CA2246398C - Seal electrical conductor arrangement for use with a well bore in hazardous areas - Google Patents

Abstract

The present invention relates to a protective sheath for protection and separating a plurality of insulated cable conductors from a single cable that includes a layer of protective armor surrounding all the conductors extending from down hole along production tubing in an underground well. The protective armor terminates at a separating point of the cable conductors so that the plurality of cable conductors are separated into individual cable conductors.
The sheath is comprised a hollow rigid tube for enclosing the plurality of insulated cable conductors and protective armor.
A plurality of individual rigid tubes are integrally formed to and enclose one end of the rigid tube so that each one of the plurality of cable conductors is routed into a separate rigid tube. Each one of the plurality of rigid tubes encloses a corresponding one of the individual cable conductors. The rigid tube and individual rigid tubes are sized to confine but not sealingly engage the conductors when the well is pressurized for preventing excessive expansion of the insulation on the conductors during well depressurization.

Description

SEAL ELECTRICAL CONDUCTOR ARRANGEMENT FOR USE WITH
A WEL~ BORE IN HAZARDOUS AREAS

This is a division of co-pendinq Canadian Patent Application Serial Number 2,159,448 which entered the national phase in Canada on September 28, 1995 and which was filed as a PCT Application Serial Number PCT/US93/04032 on April 29, 1993.

STATEMENT OF PRIOR ART
Substantial difficulty has heret:ofore been encountered in providing a sealed arrangement for supplying electrical power to a sealed wellhead over a petroleum producing well bore in a hazardous area where explosions or fires may occur due to gases and other substances associated with the production of petroleum products being ignited by electric arcs. Also, personnel and the general public are subject to electrical shock or death by electrocution.
So far as known to applicant, there has not heretofore been provided a satisfactory and safe method and arrangement for supplying electrical power through power source electrical conductor means to electr cal conductor means extending through a sealed barrier associated with a wellhead associated with a well bore in a hazardous area to overcome the above and other problems.
Present commonly employed electrical installations for supplying electr~cal power through the wellhead and into the well bore for various purposes typically consist of a flexible corrugated electrical conductor means extending through the wellhead which are connected externally of the well bore with the power source electrical conductor means.
It is substantially difficult, if nol impossible, to initiate and/or maintain an effective seal with the corrugated cable as WO 94l~726 PCT~S93/0~32 it p~cre- through the wellhead to prevent discharge of fluids in the hazardous area. The internal elements of the electrical cable are also subject to transmitting well bore liquids and gases therethrough. The gases and liquids pass through the electrical conductor means to an electrical enclosure in an adjacent non-hazardous area which creates another hazardous area. Arcing in the enclosure can cause an explosive situation. From this point, the power source electrical conductor means continues from ~ou.ld level to the level of the power transformer. Such outdoor electrical installation is not in compliance with commonly accepted electrical practices and requirements, whether such installations occur in a hazardous or in a non-hazardous location.
Designs previously and currently in use fail to ov~ ome the problems presented by the above installations. Both previous and current products employ the use of an attachment plug and ~ece~acle, which constitutes a means by which the device being powered can be disconnected while power continues to be supplied to the power source electrical conductor means. The attachment plug and receptacle constitutes disconnecting means which requires that the attachment plug ~nd le~ acle be rated for the same horsepower as the device to which power is being supplied. So far as known to applicant, no such rating is possible, especially since such plug and receptacle should also be capable of withstAn~i~7 an internal explosion without spreading such explosion.
Inside the wellhead barrier, it is desirable to provide connectors to connect the power conductors to the pump cables from a down hole pump. These connectors allow easy removal in case the well is pulled. However, problems have arisen where the connectors have been disconnected andl or damaged due to . . ~ . , . , ~, ~0 94l25726 PCT~US93/0~32 changes in pressure when the pump is turned on or off.
It is known that the inC~ tion surrounding conductors and the rubber typically used for insulation boots are permeable to fluids, such as gas and other liquids in the well bore. Pressurized and fluid impregnated rubber tends to fill gaps and ex~s~ s~ams causing paths for fluid to escape to undesired areas. A well is typically pressurized due to ~,es~u~cs exerted by the formation, and can reach pressures at the wellhead 10 in ~yc~sc of 5,000 to 10,000 pounds per square inch (psi) while the down hole pump is turned off. Such high pressure forces fluids to saturate any gas permeable materials such as rubber and insulation, which would then leak to the con~l~ctors and reach external areas where well fluids are undesired via the conductors causing a hazardous situation.
~ or example, in my previous United States Patent No. 4,614,393, it was disclosed how to seal electrical conductors passing t~rough a packer within separate -steel tubes to provide cQ~ ction from a low pressurearea above the packer to a high pressure area below the packer. Steel tubes were inserted through a penetrator of the packer, where the steel tubes were terminated on either side of the packer using the power cable co.ll.e_tors disclosed. An i~F~lAtor stand off was provided to electrically isolate a connector socket used to terminate the con~l~ctor and the steel tube. It has been discovered, howev~., that well fluids tend to penetrate the rubber boots ~L~.ding the connector elements and reach the conductive wire, thereby penetrating the insulator stand off. The fluid slowly eCcares to the low pressure area via the conductors.
~t is desired, therefore, to provide a ~ore effective fluid seal, so that connectors placed in down hole WO 94n5726 PCT~US9310~32 pressurized areas will not leak fluids to the low pressure area.
It has also been discovered that prior connectors tended to separate when the fluid-impregnated rubber boots are s~ e~ly depressurized. Depressurization oc~s when the down hole pump is shut off causing a pressure differential between the fluid-impregnated ~oots and the depressurized area surrounding the connector, since the rubber boots are unable to release the fluids fast ~nough. Thus, the rubber boots tended to expand, forcing apart the ~ating counterparts of the connector causing ~i~cQn~ection. An external protective shield was provided to protect the rubber and prevent outward expansion, where the outward shield itself composed two ~ating parts for allowing the con~ction to be ~isconnected. Even if the two parts of the protective shield ~ere fastened or otherwige locked together, the pressurized fluid within the rubber caused a piston effect, forcing the electrical connection apart due to t~e pressure differential. It is therefore desirable to provide a connector capable of remaining intact during pres6urization and depressurization within the well.
q~he power i$ typically supplied using three separate conductors preferably con~ncting three phase current. The wellhead generally comprises ferromagnetic tubing spools and tube hangers to achieve the nec~ss~ry strength without undue cost. To meet S
300-20 of the National Electric Code (NEC), which concerns induced currents in metal enclosures, the three conductors carrying alternating three phase current are typically y.ou~ed together to avoid heating the surrounding ferromagnetic metal by induction. A
single conductor carrying alternating current causes alternating magnetic flux, which induces electrical WO 94/~726 PCT~S93/0~32 eddy currents generating heat in the surrounding ferromagnetic material. Grouping the conductors together in a triangular fashion results in c~c~l1Ation of a significant amount of the magnetic flux, thereby reducing the electrical eddy currents and heat by induction. However, grouping the conductors also creates a larger hole nore than twice the diameter of a single hole, causing an increased radial profile penetrating the wellhead. A single large hole is more difficult to seal than several smaller holes. More significantly, a single large hole forces an off-center d, or eccentric, main pipe through the wellhead, llc~ ly resulting in a wellhead ~aving a larger diameter. There is a significant increase in cost associated with an increase in wellhead diameter.
For example, certain discrete wellhead sizes are manufa~L~ , where the typical cost ~etween one well h~ size and the next larger size is approximately Slo,ooo. It is desirable, therefore, to separate the con~llctors to reduce the radial profile of the electrical ~_Glu ~-Lion. Separate cor~ ctors are only allowed under NEC S 300-20 if slots are cut in the s~l~G~ ing metal, or if the conductors are passed thluu~ll an insulating wall sufficiently large for all of the conductors. Neither of these alternatives are practical or desirable for use in wellheads. Slots would eliminate the ne~es6~ry seal, and an insulating wall so described is not ~easible and would also compro~ise seal integrity.
8n~Y or ~E PR~8~N~ ON
An object of the present invention is to overcome the problems presented by prior devices and electrical arra~,g~ -nts used in hazardous areas.
An object of the present invention is to provide a relatively simple method and arrangement for supplying WO 94ns726 PCTrUS93tO~2 electrical power through power source electrical conductor means and connecting such electrical conductor means with the electrical conductor means associated with a wellhead in a hazardous area for supplying electrical power into a well bore for various purposes, by way of example only, 6uch as a down hole electrical pump, instruments and other down hole equipment.
Another object of the invention is to provide a lo splicing and conduit arrangement which safely conducts power to electrical conductor means extending through a sealed barrier in a sealed wellhead that is positioned in a hazardous area subject to explosions ~nd fires.
Another object of the present invention is to provide a rigid conduit including a splice fitting whereby a splice may be formed which separates the electrical conductor means of a well bore power cable from the power source electrical c~n~ll~tor means and seal means in the rigid cQndllit means ~etween the splice fitting ~nd the rigid conduit with breather vent me~ns so as to inhibit the passage of fluids from the electrical conductor means to the power source electrical conductor means.
Another object of the present invention is to provide an arrangement for securing a power source electrical conductor means adjacent a wellhead for supplying power to electrical conductor means ~hat extend into a se~led barrier associated with the wellhead which inhibits explosions ~nd fires in the hazardous area.
A further object of the present invention is to provide an arrangement for supplying electrical power from a power source electrical conductor means in a rigid conduit which may be secured adjacent the wellhead and which is arranged so that the rigid ~ ., ., . ., . ~., W O 94~5726 P~rnUS93104032 con~--it and electrical conductor means therein may be disconnected from the wellhead and removed from the wellhead outside the hazardous area.
A connector within the well is provided, which S includes an outer shell attached to a top stop and a bottom stop confining rubber boots surrounding the electrical connection. During depressurization near the wellhead when the down hole pump is turned on or the casing annulus pressure is bled off, the rubber boots are prevented from PYr~ing due to the outer shell and top and bottom stops, so that the connDction remains intact.
The conductors pass through the wellhead through rigid tubes and into COL~C_I~OI~ilinq conn~ctors according to the present invention. The ~on~ tor extends beyond the rigid tube and is terminated with a first connector means, such as a female co~nector socket, which is adapted to electrically engage a F~oon~ conductor means, such as a c~L~f~lol~Aing male connection pin. A
stand off is provided around the co~ ctor between the rigid tube and the first connector means to ~evellL
electrical conduction to the rigid tube. The standoff includes an extension lip counter bored to tightly fit around the rigid tube, and an internal shoulder abutting the end of the rigid tube. In this manner, the stand off is forced against the rigid tube forming an effective fluid seal.
The conductors providing three-phase current pene~.ating the wellhead are aligned to achieve a narrower radial profile than that previously possible.
The conductors are preferably arranged side-by-side, although not limited to this configuration, along an arc of a circle having its center the same as the center of the wellhead. Each conductor is surrounded by a rigid tube comprising a non-ferromagnetic, ,, .. . , .. , ~

WO 94l257~ PCTnUS93/0~2 electrically conductive material, where the rigid tube acts as an eddy current shunt for electrical eddy currents induced by the magnetic fields generated by the alternating current flowing through the conductors.
In this manner, electrical eddy currents do not flow in the wellhead, which would otherwise consume valuable energy and create undesired heat.
A rigid seal means ~e?l~hly secures the rigid tubes penetrating the wellhead to protect the conductors. A ferrule-type fitting is provided on the outside of the b~rrier or wellhead, which includes a ferrule according to the present invention allowing the fitting to be removed without destroying the rigid tub~s. The ferrule comprises a resilient material, such as, but not limited to, hard plastic rated for high temperature, and more preferably a polyimide resin. The ferrule is softer than the rigid tube so t~at it does not permanently bite into the rigid tube.
Thus, the ferrule is not permanently attarh6d to the rigid tube, and may be readily removed when the well is pulled.
A protective metal sheath according to the present invention protects the insulation of the down hole cable conductors in the well and provides axial column strength for the conductors. The triskelion ~L~O~ S
and protects the ins~llAtion of the cable conductors by pL~ve..~ing sudden ~ypansion during decompression when the down hole pu~p is LuL~d on, or when the casing annulus pressure is bled off, where the i nr~- I ation would otherwise expand and possibly break causing electrical ~ailure. The triskelion is Ayially fixed in position to the production tubing to provide the column strength. The triskelion also provides a protective transition between a single 3-wire cable extending from down hole to three single wire conduits.

.. . ~ ~, An alternative form of splice fitting includes a breather boot wit.h a breather passage sealed with silicone compound to protect the electrical connection between the power electrical conductor and the electrical conductor extending through the wellhead barrier from water or moisture. The breather passage extends into the breather boot to the exposed conductor wire of the electrical conductor extending through the wellhead barrier. Thus, if the seal in the wellhead barrier should fail allowing well fluids to reach the splice fitting v:a the electrical conductor, the sllicone compound is displaced with the well fluids at a lower pressure than the pressure required to reach the power electrical conductor. This allows the well fluids to escape the breather boot into the splice fitting.
Thus, the well f:Luids are prevented from reaching a non-hazardous area v:ia the power electrical conductor.
In accordance with one aspect of the present invention there is provided a protective sheath for protection and separating a plurality of insulated -able conductors from a 2CI single cable tha~ includes a layer of protective armor surrounding all the conductors extending from down hole along production tubing in an underground well, wherein the protective armor terminates at a separating point of the cable conductors so that the plurality of cable conductors are separated into individual cable conductors, said sheath comprising: a hollow rigid tube for enclosing the plurality of insulated cable conductors and protective armor; and a plurality of individual rigid tubes integrally formed to and enclosing one end of said rigid tube so that each one of the plurality of cable conductors is routed into a separate rigid tube wherein each one of said plurality of rigid tubes encloses a corresponding one of the individual cable conductors; the rigid tube and individual rigid tubes being sized to confine but not sealingly engage the conductors when the well is pressurized for preventing excessive expansion of the insulation on the conductors during well depressurization.

9a BRIEF DESCRIPTION OF THE DRAWINGS
The present invention, taken in conjunction with the invention disclosed in co-pending Canadian Patent Application Serial Number 2,159,448 which entered the national phase in Canada on September 28, 1995, will now be described in detail with the aid of t:he accompanying drawings, in which:
Fig. 1 is a side view of one preferred form of the present invention;
Fig. 2 is a top plan view looking down on Fig. l;
Fig. 3 is a sectional side view partly in elevation on the line 3-3 of Fig. l;
Fig. 4 is a top plan view of one form of splice fitting, with the cover removed, which may be employed to receive a formed splice which connects power source electrical conductor means with electrical conductor means in a hazardous area where the present invention is employed;

WO 94~5726 PCT~S93/~32 Fig. 5 is a side sectional view, partly in elevation, showing a splice completed in the splice fitting of Fig. 4 with a cover thereon;
Fig. 6 is a side sectional view similar to Fig. 5 with the cap or cover of the splice fitting removed and illustrating the position of the splice before it is completed and positioned as illustrated in Figs. 4 and 5;
Fig. 7 is a view similar to Fig. 6 showing an alternate form barrier for the wellhead;
Fig. 8 is a front view of electrical connection apparatus according to the present invention within the well bore of a well;
Fig. 9 is an enlarged view of connector within the well shown in Fig. 3;
Fig. 10 is an exploded side view of the connector of Fig. 9;
Fig. 11 is a partial sectional view illustrating a stand off according to the present invention within the connector of Fig. 9;
Fig. 12 is a partial sectional front view of a wellhead illustrating relative positioning according to the present invention of electrical conductor6 penetrating the wellhead;
Fig. 13 is a partial sectional view of a rigid seal means for Realably securing the rigid tube within the wellhead;
Figs. 14 and 14A are sectional views of a triskelion according to the present invention for protecting down hole cables; and Figs. 15 and l5A are sectional views of an alternative emho~i ?nt of the triskelion of Fig. 14;
Fiq. 16 is a top plan view of another form of a splice fitting according to the present invention, with 3s the cover removed, for connecting a power source ,. .. . . .

WO 94l2~726 PCT/US93/04032 electrical conductor means with a electrical conductor means in a hazardous area where the present invention is employed;
Fig. 17 is a sectional side view showing a splice completed in the splice fîtting of Fig. 16 with a cover thereon;
Fig. 18 i6 a sectional side view similar to ~ig.
17, with the cap or cover of the splice fittinq removed, to illustrate the position of the splice before it is completed and positioned as illustrated in Figs. 16 and 17;
Fig. 19 is a more detailed partial cross-sectional and L ~'e ed view of the electrical connection of Fig.
17; and Figs. 20A-20F are cross-sectional views of the electrical connection within the breather boots of Figs. 16-18 loo~ng along lines 20A-20A, 20B-20B, 20C-20C, 20D-20D, 20E-20E and 20F-20F, respectively, of Fig. 19.
D~CR~PTTON OF ~p~ p~F~p~n ~XBODr~aE~
Attention is first directed to Fig. 3 of the drawings wherein a w~llh~Ad arrangenent is referred to generally by the letters W~. Wellhe~ may assume various forms and configurations but generally include some type of me~ber such as by way of example a tubing spool 7 secured by suitable means such as bolts as shown to the casing C which projects upward from the earth E which creates a hazardous area. A tu~ing hanger 8 may be positioned within the bore of the tubing spool 7 as shown in the drawings for supporting a tubing (not shown) which extends downwardly into the well bore through which the well fluids are conducted from the producing formation(s) in the well bore to the earth's surface. An adapter spool 9 is illustrated as W O 94125726 CA 02246398 1998-10-06 PCTtUS93/04032 positioned on top of the tubing spool and is adapted to receive a master control valve (not shown) on the top thereof for use in a manner well known in the art.
It can be appreciated that the wellhead configuration and components may change from that illustrated in Fig. 3 which is given by way of example only. Regardles~ of the configuration and components of a wellhead, the present invention may be employed to connect power source electrical con~-~ctor means with lo electrical conductor means which sealably extends through the wellhead.
The tubing ~anger forms a barrier in the wellhead through which electrical cQn~ctor means must extend for cQnnection with an external power source to supply power as may be desired to an instrument, down hole pump or other device.
The power source electrical conductor means and the electrical conductor means may be of any well known type, such as by way of example only, each may comprise multiple separate electrical conductors where each electrical con~ tor is i n~l lAted and all the multiple electrical conductors enclosed or encased in a sheath or outer protective jacket. The power source and electrical conductor means may each consist of a single conductor in a sheath or other protective cover.
The present invention will be described in detail as employing separate multiple electrical conductor means, but as noted this is by way of example only.
As illustrated in Fig. 3, the electrical conductor means for a well bore cable is shown as having separate electrical conductor means 10, 11 and 12. As shown in Fig. 3, these separate electrical conductor means extend through t~he tubing hanger, and each is enclosed within a separate rigid tube means each of which tube means may be designated 15 which rigid tube means ,. . , "~, .

WO 94!~ n6 PCTrUS93/0~32 sealably extends through the tubing hanger and the lower annular flange 16 of adapter spool 9 which forms one type of sealed barrier for the wellhead WH.
Each of the rigid tube ~eans 15 is preferably formed of material considered to be non-ferromagnetic such as by way of example only stainless steel, which is resistant to attack by fluids in the well bore or in the Du~lou.-ding hazardous zone. Each tube means 15 is se-lAhly secured by suitable rigid seal means 20, 20' lo in the wellhead. The rigid seal means 20', 26 may be any suitable well known rigid seal mean6 such as Swagelok~ or the like which are available over the counter and which are ~u.LGsive resistant and considered to be non-ferroJagnetic may be employed.
Upper rigid ~eal means designated 20 sealably secures said rigid tube means 15 with the flange 16 and also ~e-l ~hly ~ecure one end of the conduit portion 25 with the wellhe~d WH and/or the rigid tube means 15.
Rigid seal means 26 secure the other end of the con~it portion 25 with the splice fitting 42. Additional or lower rigid seal means 20' se~l~hly secures the rigid tube means 15 in the tubing hanger 8 and preferably adjacent the lower end thereof, but this position may be ch~ , if desired.-The barrier is illustrated in Fig. 3 as comprising the tubing hanger 8 and flange 16. It may be varied by the way of example, to compri6e only the tubing hanger 8 or flanse 16.
Where the barrier in the wellhead consists of only the tubing hanger 8 as shown in Fig. 7, a single rigid ~eal means may be employed under some conditions to secure rigid tube means 15 with the hanger 8 but it is preferred that the upper and lower rigid seal means 20, 20' e~ch be positioned as shown in Fig. 7 to sealably secure said rigid tube means 15 with the hanger.

WO 94l25726 PCTrUS93/0~32 Should the annular flange 16 be employed as the barrier then tbe rigid seal means 20 may be connected at a sinqle location to sealably secure the rigid tube means 15 passing therethrough, or to same double rigid seal means 20, 20' arrangement described above when the tubing hanger serves as the barrier may be employed to ~e~]~hly secure with the flange lS and the rigid tube means ~5. It c~n be appreciated that the location of the rigid 6eal means 20, 20' in any situation may be lo varied to accomplish the desired sealing effect with the hanger 8 and~or the flange 16.
Regardless of the form of barrier, the conduit portion 25 is Oeal~bly secured therewith as described above.
In the embodiment illustrated in Fig. 3, the electrical conductor means 10, 11, 12 are each further protected by the rigid tubes 15 which ~u~loul-d each of the electrical ~on~ctor means from the sealing tube fitting 20' at the lower end of the tubing hanger 8 and each rigid tube means extends to a separate co~ector .e~.cOented generally by the numeral 23 wherein the three down hole separate electrical conductor means of the well bore power cable are each connected with one of the separate connectors 23. Suitable protection means ouch as flexible or rigid tube means forming con~l~ctor extensions 24 separately su~Lo~nd each of the electrical conductor means and APP~d or extend downwardly in the well bore to te~ i~ate adjacent the protective jacket on the power cable which jacket receives ~nd encloses all three electrical conductor means therein. The rigid me~ns 20', 26 employed provide a metal to metal seal between the components.
It can be appreciated that the wellhead and tubing hanger are provided with suitable seals as illustrated ,.~

W O 94ns726 P~rrUS93/04432 in Fig. 3 for inhibiting the flow of fluid therefrom in a undesired manner.
Where the electrical conductor means comprise separate insulated electrical conductor means lO, ll, 12 as shown in Fig. 3 each may be received in a separate conduit portion 25, which as previously noted, is sealably secured at one end by the rigid seal means 20 to the wellhe~ WH and at its other end by the rigid seal means 26. Where the electrical con~-lctor means consists of a plurality of separate insulated electrical conductor means encl 06-~ in a sheath or a single electrical con~ctor ~eans in a sheath which extends through the wellh~A~, then there is only a single conduit portion 25 ~e-lAhly secured adjacent the barrier and adjacent splice fitting 42 by rigid seal means 26. The rigid means 26 is preferably a swivel nut Swagelok~ fitting to enable the arrangecent of the present invention to be more readily disconnected from the wellhe~ as will be described herein. The conduit portion(s1 25 may be flexible or rigid of any suitable type to withstand the conditions under which they will be employed and to safely supply the power from the power source electrical conductor means to the electrical conductor means of the power cable ext~n~ing downwardly in the well bore (not ~hown). The conduit portion(s) 25 should be capable of withst~n~jng a minimum of 600 p$i internal test pressure and are preferably formed of Monel 400 which is considered to be non-ferromagnetic and which will withstand the corrosive conditions to which the flexible electrical con~-~;ts may be subjected. Any other suitable flexible or rigid material which is corrosive resistant and considered non-ferromagnetic and capable of withstanding 600 psi internal test pressure may be used. The conduit portion(s) may be obtained from any WO 94l25726 PCTnUS93/0~32 suitable source and is an over the counter type of the product with one form including a metal internal WO 941~726 PCTnUS93/~32 material which provides as much and preferably more electrical insulation than that of the electrical insulation of the conductors to be spliced, such as delrin. Where the power source and electrical conductor means consist of ~eparate electric conductor means, then separate pA Cs~ges of the same number as the electrical conductor means will be provided in jnclllAting member 46. In the embodiment shown in Figs.
4-6, three 6eparate passages 47, 48 and 4~ extend lo through the member 46 to receive 10, 11, 12 and lOa, lla, 12a as shown in Fig. 4. The pAss~ges 47, 48 and 49 which extend from the one end 40 and into the member 46 are of less lateral extent than the portion of each p~CsAge which extends inwardly from the other end 51 of the member 46 as shown in Fig. 5. The junction of the enlarged passage portions ext~n~ing from the end 51 with the smaller pACs~ges extDn~ing from the end 50 of the member 46 provide a shoulder 53 as shown. The passages 47, 48 and 49 co~municating with the end 50 each receive therein one of the power source electrical cQn~l~ctor means lOa, lla, 12a exten~i~g through rigid con~l~it means 40 from the cable t~at enclçses them and cu.~,e_Ls with a suitable power source (not shown) as illustrated in Fig. 4. The conductor element or portion of each of the power source electrical con~-70ting means is exposed as shown at lOa', lla' and 12a' respectively. Separate splice connectors 55 are shown, each of which has a passage which extends partially from one end of each co~ector for receiving the ~Ypose~ portions lOa', lla' and 12a' of each of the power source electrical conducting means and each splice connector 55 is provided with suitable means such as a screw 58 for securing each of the exposed elements of each of the electrical conductor means in WO 94l~726 PCTrUS93/0~32 one end of the electrical conductor splice connector 55.
Similarly, the ~Y~osed conductor element portion 10', 11' and 12' of each of the electrical conductor means 10, ll and 12 is ~Yro~~~ as shown in Figs. 4 and 5 and each extends into a passage exton~ing into the other end of each electrical conductor splice connector 55 and is secured therewith by a screw 58' or the like.
The member 46 may then be moved to a desired position within the splice fitting 42 and the cables 10, 11, 12 and lOa, lla, 12a positioned 50 that if desired one end of the member 46 may abut the shoulder 53 as shown in Fig. 5. An insulating ~crew 60 formed of plastic or the like may be positioned between the two longitudinally spaced screws 58 and 58' on the center member 55 to retain the splice connectors 55 in position as desired within the jn~ ting ~ember 46.
If desired, additional ;~ ting 8~;~e~s may be positioned in me$~3er 46 to abut the end of each splice co~ector 55 which is adjacent the outer ~plice conn~ctor 55 ne~rest the end 51 of m~m~r 46.
To assure that the present invention will function within the hazardous area as desired, it is preferable in most instances, that a seal means represented by the numeral 65 be provided in the conduit downstream of the splice fitting 42 adjacent the wellh~d in which the plural electrical conductors of the power source are spliced with the multiple electrical conductors of the down hole power cable as previously described.
The seal means 65 is downstream from the wellhead and compri6e~ a seal fitting 66 with a sealant 67 therein. The F~-lAnt 67 is preferably and should be obtained from the manufacturer of the seal fitting.
For example, in the present instance the seal fitting is catalogue No. EYD6, used as one off the shelf .. . . .

WO 94l~726 PCTrUS93/0~32 example of a suitable fitting which may be employed and is manufactured by Crouse-Hinds and the ~eal compound or sealing means of Cro~re Hinds should be employed with that fitting. Where a seal fitting of another S manufacturer is e~ployed, then that manufacturer's seal means including its 5~AlAnt compound is employed.
Particular means of Crouse-Hinds for the specific seal fitting above designated, comprises a compound and a fiber. Crouse-Hinds refers to its 6ealant compound as Chico A and the fiber is referred to as Chico X. To form the 6eal means 6S, the seal fitting 66 may be provided with the sealing 67 prior to or after its connection with the nipple 31 which is connected to the end 42a of splice fitting 42. In either situation the Chico X fiber is 6tuffed in the fitting 66 and then Chico A compound is mixed with water in accordance with the manufacturer's instructions and then poured into the seal fitting on top of the fiber. The thickness, or longitudinal extent of the sealant 67 formed within a seal fitting must at least be equal in longitudinal length to the diameter of the fitting member in which it is positioned. It is recommendéd that the minimum diameter of the conduit or tubular member for receiving the plural electrical power conductors from the power source and various fittings employed herein have a minimum diameter of 2 inch~s, then the minimum longit~ inAl extent of the seal fitting 66 should be not less than 2 i n~h~c . As better seen in Figs. 5 and 6, ~ nipple 31 is connected between the seal fitting 66 and the end 42a of splice fitting 42. Where the seal fitting 66 is secured in position between nipple 31 and conduit 40, the sealant 67 is formed therein by inserting Chico X and Chico A and then adding Chico A
compound as described above. The seal fitting 66 includes the plug 68 and breather 69 as best ~. , WO 94125726 PCT~S9310~32 illustrated in Figs. l and 3 with another seal fitting 66' shown connected in the downward extension of conduit 40 outside the hazardous area as shown in Fig.
l, and the sealant may be formed by removing plug 68 and then repositioning the plug in the seal fitting after the sealant is formed in the fitting. The 6ealant 67 is formed within the seal fitting 66 and is within 18 inches from the adjacent splice fitting 42.
In the preferred embodiment illustrated, such female seal fitting 66 is for sealing in a vertical or a horizontal position and is preferably by way of example only, the EYD6 of Crouse-~inds, as previously noted. It can be appreciated that other conduit seal fittings, vertical or horizontal, male and female, elbow seal, female hubs, male and female hub may be employed in certain situations.
The seal fitting 66 shown in Fig. 3 is connected at its end 66b to the ron~l~it 40, and also inc}udes a plug 68. A breather or vent 69 in the seal fitting 66 is between the -~rlAnt and the well~ in the drawings. Seal fittings 66 and 66' are preferably the same. Seal fitting 66 is connected in the conduit 40 and then connects with splice fitting 42 which in the preferred embodiment is adjacent the wellhead in the hazardous area. Seal fitting 66' is connected in con~t~it 40 outside the haz~rdous area.
The seal means 65 including seal fitting 66, ~ nt 67 and breather tube or vent means 69 are for allowing an internal explosion to occur therein and in the arrangement in a hazardous situation without conveying the explosion internally of the conduit 40 or externally thereof. Also, it accommodates a flame or fire within such confinement, without permitting or conveying the fl~e externally. The breather vent is constructed in a well known manner to contain internal ,W O 9~25726 P~r~US93/04032 explosions and first or fla~es within the arrangement.
In addition to the foregoing the breather tube 69 aids in Ai ~ch~rging fluids, liquids and gases from the seal fitting 66. In this regard, it should be noted also S that the sealing compound used in conduit seal fittings is somewhat porous so that gases, particularly those under slight ~eE~ure with small molecules such as hy~Gyen ~ay pass slowly through the sealing compound.
Also, it should be noted that there is no gasket between the splice fitting 42 and the cover 43 to permit the Ai --h~ge of fluids from the splice fitting 42 to the ~u~Lo~.~ing atmosphere. If any gas or fluid should migrate through the insulation of the electrical con~Al~ctors 10, 11 and 12 between the wellhead and the splice fitting, gas is permitted to escape through the conA~it seal fitting 66 th ou~h the breather 69, as noted previously.
Also, the arrangement and configuration of the splice within the splice fitting 42 does not directly conn~ct or join the two sets of cables in engagement together and thereby isolates the multiple conductors of the power cable from the plural conA~ctors of the power source to further inhibit movement of gas and/or liquids from the well bore through the conduit 40 and the electrical ~Qn~stors.
The rigid ~Qn~ t ~eans 40 may extend from the wellhead in an elevated relationship as illustrated and then the portion thereof as shown in Fig. 1 ~p~n~c downwardly into the earth ~L C cnted by the letter E
at a location as illustrated at 40c in Figs. 1 and 3 beyo..d the portion or area classified as hazardous.
Another splice fitting 42' may be provided and a splice formed therein in the manner as described and illustrated with regard to Figs. 4, 5 and 6 herein to connect electrical conductors from a power source with .. , .,~ ,. . . .

, W O 94125726 F~rrUS93/04432 the plural electrical conductors in rigid conduit means 40. In thi6 situation a union 88 may be threadedly con~ected with the end of the splice fitting 66' as indicated and also connected with the seal fitting 66' S therebeneath. The seal fitting 66' is connected in turn to an elbow 71 that extends into the ground at the location outside the hazardous area. The splice fitting 42' is also preferably provided within 18 inrh~s of splice fitting 42~ as previously described lo with regard to splice fitting 42.
Suitable ~ L means are provided for securing or loc~ing the splice fitting 42 and conduit means 40 in position adjacent the wellheA~ and such means includes a bracket represented by the letter B with a portion 70 secured to the wellhead in any ~uitable manner such as by the bolt and nut means as illustrated in Fig. 3 of the drawings. The bracket B has a lower upwardly extending portion 71 and a ~eparate upper portion 72 for conn~ction with the lower upwardly ext~ portion 71. The top edge of lower portion 71 and the bottom edge of the upper portion 72 ~re each provided with matc~ing semi-circular recess 71a', 72a' to receive the end 42c of splice fitting 42 there through as shown in Fig. 3 of the drawings. Suitable bolts (not shown) may then be ~e~ d through the upper portion 72 to extend into the lower 71 to secure the bracket in position with the splice connected as shown in Fig. 3.
In the emho~i -nt illustrated, ~uitable means as provided to lock the splice fitting 42 to or adjacent the bracket B and to the wellhead. Such means ~ay assume any form and as illustrated includes the semi-circular rings 74 and 75 on the lower and upper upwardly extending portions 71, 72 respectively which rings project beyond the semi-circular recess defined . ,~, , , , ~

~WO 94/~726 PCT~US93/0~32 by the mating lower and upper bracket portions 71, 72.
The rings 74, 75 extend into a groove 42d formed in the splice fitting and thereby lock the splice fitting and bracket to the wellhead.
In another form, the securing means may be in the form of a nipple that is threaded into the end 42c of the splice fitting 42 and is provided with an end that is threaded externally and which projects through a circular op~ing in a bracket portion which extends upwardly from the portion 70 to receive the end 42c of the fitting therethrough. The threaded nipple end projects through the opening in the upstanding bracket portion receives a threaded ring thereon that abuts the upst~ndi n~ bracket portion to secure the splice fitting 42 in position adjacent the wellhead.
In Fig. 6 any suitable instrument such as a screwdriver 81 may be employed to secure the screws 58, 58' of each of the splice connectors 55 with the respective conduit e~G~' ends of the plural conductors of the power cable and the ~ultiple conductors of the down hole cable.
A suitable housing H is provided to enclose the splice fitting 42 adjacent the wellhead to inhibit fluid such as water and the like from entering thereinto. Such housing as shown in Fig. 3 includes a top wall 82, side walls 83 and an end wall 84 as shown.
It will be noted that the top cover 82 of the housing H
is provided with a cut away portion represented at 86 in Fig. 3 so that the housing fits snugly adjacent a portion of the spool 9 as illustrated. One of the side walls such as the wall 83 is provided with an opening 85 to enable the splice cGI~.e_Lor 42 to extend therethrough for communication with the conduit 40.
The housing H is secured to the bracket B by non-tamper screws or nuts represented at 87 in dotted line.

WO 9A12~7t6 PCr/US93104~)32 Similarly, the covers 43 for the splice fittings 42, 42' are maintained in position by non-tamper means 87 well known in the art to inhibit access, except with special tools. This effectively locks the housing H
and caps 43, 43' in place so that access can be gained only by authorized personnel. The splice fitting 42' outside the hazardous area connects the horizontal portion of the con~llit means 40 with the vertical portion thereof as shown, and as previously noted, a splice is formed therein in the manner as described with regard to the splice fitting 42.
The present invention is advantageous in that it provides an arrangement so that the power source electrical conducting means which supply power to the wellhead are maintained in a co~uit, which conduit can be easily moved out of the way or ~i~co~ected from the wellh~A~ when desired.
To effect such ~icconnection and/or removal, the ~plice in the splice fitting 42 immediately adjacent the wellhe~ rco~nected by reversing the splicing p.oceJ-~e previously described and the splice fitting 42 is unlocked from the bracket B. The union 88 may be rotated whereupon the conduit means 40 with the power cable therein can be rotated sufficiently to displace it from the wellhead. At the sàme ti~me as the splice in fitting 42 is disconnected or thereafter, the splice in the splice fitting 42 may be di~co~nected and the union ~i~connected from the splice fitting so that the entire horizontally exten~i~g rigid conduit ~ean6 40 may be removed to a remote location while wellhead operations are conducted.
In the preferred embodiment the conduit means 40 extends from it6 connection with the wellhead in horizontal elevated plane or position above the earth as shown.

WO 94/~726 PCTrUS9310~32 Where the electrical conductor means is a single large member, an offset tubing hanger may be required to accommodate passage of such conductor therethrough.
Also, it can be appreciated that the con~lit portion 25 may be formed by exten~ing rigid tube means 15, or by a separate conduit portion connecting directly into the p~s~e(s) in the barrier for communicating with the rigid tube means se-lAhly secured therein. It can be further understood that the conne~tor arr~n~ -nt 24 can be modified to provide a single connector where the electrical conductor means is a single member.
PreferAbly the outer jacket and any other coverings of the power source electrical con~ tor means should be removed so that the sealing compound, or sealant 67, in the seal fitting 66 will ~u~.d each individual inc~ ted conductor and the outer jacket.
Referring now to Figure 8, a front view is shown of apparatus according to the present invention within the well bore below the barrier or wel Ih~ l. In the preferred embodi~ent, three similar rigid tubes 15 enclosing the electrical con~llctor means 10, 11, 12 co.~ L to three similar connectors 23. The connectors 23 cG..ne_L the electrical conductor means 10, 11, 12 to three separate and similar down hole cable conductors 118 (Fig. 9) extending from down hole from a pump or similar electrical apparatus requiring power. The connectors 23 connect to a triskelion 150, which is used to protect the down hole cable conductors 118, to provide column SutJ~G and to provide a transition from a 3-wire cable 155 containing the three down hole cable conductors 118 to the three single c~ble con~lctor extensions 24. ~he tr;s~elion 150 and the 3 wire cable lS5 are banded or otherwise clamped using clamp means 160 to production tubing 162.

, .~ " .. . ..

W0~4/~726 PCT~S931~32 Referring now to Figure 9, an enlarged view of one of the connectors 23 is shown- Only the connection for the electrical conductor means 11 is shown and its c~e,~o"~ing rigid tube 15, it being understood that similar connections and apparatus are used for the electrical .o.,l~Lor means 10, 12, if included. The rigid tube 15 is inserted and p~es throush a top fitting 100 and a top stop 102. The top fitting lOo and top stop 102 are preferably made of a non-lo ferromagnetic, electrically conAItctive material, suchas stainless steel, for examplel or the like. The top fitting 100 is preferably a ferrule-type fitting, such as, for example, Swagelok~ or the like, so that the top fitting 100 is fixedly attached to the rigid tube 15.
- 15 The top fitting 100 preferably includes four parts, including an upper fitting lOOa, a lower fitting lOOb and a two-piece ferrule (not shown) for ~ecuring the top fitting 100 to the rigid tube 15. The lower fitting lOOb includes a threaded extension lOOc for interfacing a threaded hole 102a of the top stop 102, so that the top fitting 100 is s~,awed into the top stop 102. Alternatively, the lower fitting 100b of the top fitting 100 may be integrally for~ed with the top stop 102 for ~o,.~e..ience and re~ce~ cost.
The top fitting 100 is preferably a close fit having a relatively tight tolerance around the rigid tube 15. The top fitting 100 is preferably tightened to crimp the rigid tube 15 to preferably form a fluid seal. This choking effect of the rigid tube 15 by the top fitting 100 further prevents fluid flow from the well bore to an external low pressure area 132 through the rigid tube 15.
An outer sleeve 104, preferably comprising a hollow cylindrical tube, preferably made of a non-ferromagnetic electrically conductive material, such as ~0 94f~726 PCTrUS9310~32 stainless steel, for example, or the like, forms a protective shield circumscribing the connector 23. The outer sleeve 104 includes an upper hole 104a (Figure 10) for receiving a set screw 106. The top stop 102 includes a COL1e_~0n~in~ threaded hole 102b for receiving the screw 106. In this manner, the outer sleeve 104 is slid around the top stop 102 so that the holes 104a and 102b are aligned, and the screw 106 is screwed into the threaded hole 102b through the hole 10 104a of the outer sleeve 104 and tightened to the rigid tube 15. The outer sleeve 104 is thus fixedly attached to the top stop 102, which is att~rhe~ to or integrally formed with the top fitting 100.
Figure 10 is an exploded side view of the co~nector 23 r included for ~ oses of clarity.
The rigid tube 15 extends past the connector 23 to a lower end 110, which engages a stand off 112. The electrical conductor means 11 extends beyond the lower end 110 of the rigid tu,be 15 through the stand off 112 20 to the upper end 114a of a female connector socket 114.
The ins~ tion 113 (Figure 11) of the electrical con~lctor means 11 is stripped off exposing the conductor element portion 11', which is crimped and~or soldered to electrically and mech~nically connect it to the female connector socket 114, as known to those skilled in the art.
The female connector socket 114 includes a socket portion 114b at its opposing end for receiving a male co~ e_~ or pin 116. It is noted that the particular male and female connectors described herein could be reversed, or otherwise replaced with other slidable connector means as known, so that the present invention is not limited by any particular co~nector means. The male connector pin 116 and the female connector socket 114 are formed of any suitable electric conducting WO 94l~726 PCT~US931~32 material such as copper, or the like, and each is formed by a plurality of longit~l~in~lly extending portions which are configured to axially align and mate. A similar connection configuration is more fully described in the U.S. Patent No. 4,614,393, which is hereby incorporated by reference. In this manner, the male connector pin 116 and the female connector socket 114 are coupled together for electrically connecting one of the down hole cable conductors 118 to the electrical conductor means 11.
There are preferably three similar down hole cable conductors 118, although only one is referenced. The cable 118 extends upwards from the down hole pump to penetrate the connector 23, where the cable 118 is electrically and me~hAnically con~cted to the male connector pin 116 in a si~ilar manner as described for the electrical conductor meAns 1~ and the female conn~ctor soc~et 114.
A female boot 120, preferably comprising rubber, 20 i6 forDled to SU~LOUII~ the rigid tube 15, the stand off 112 and the female connector socket 114 for electrically isolating the rnn~l~cting portions from the outer sleeve 104. The female boot 120 preferably includes a longituAinAl p~cs~ge 120a and an arcuate 25 grove 120b for receiving a projecting end portion 122a including an arcuate, ~n~lllAr rib 122b of a male boot 122. The male boot 122 is inserted into the female boot 120 and locked as shown, where the projecting end portion 122a fills the longi~ inAl passage 120a so that the arcuate, annular rib 122b interfaces the arcuate groove 120b. The male boot 122 also comprises rubber, and is formed to ~LLOu~d the cable 118 and the male connector pin 116 for electrical isolation from the outer sleeve 104. The male and female boots 120, 35 122 have outer surfaces 120c, 122c, respectively, which W O 94/25726 P~rrUS93/04U32 are preferably formed to fill the outer sleeve 104.
The outer sleeve 104 is thus electrically isolated from the conductive portions of the connector 23.
The cable 118 extends through and past the end of the conductor extension 24 and through a bottom stop 124. The bottom stop 124 includes an ope~ing or counter bore 124a for terminating the cond-~tor extension 24. The conductor extension 24 fits re~con~hly tight into the counter bore 124a to create a relatively rigid ccnnection between the connector 23 and the t~on~ ctor extension 24. This prevents h~nr3 ing which could otherwise cut the insulation of the cable 118. The cable 118 extends past the bottom stop 124 to the male connector pin 116 within the connector 23.
The bottom stop 124 includes a threaded hole 124b for receiving a threaded set screw 126. The outer sleeve 104 includes a lower hole 104b aligning with the - threaded hole 124b for receiving the screw 126. In this manner, the screw 126 fastens the outer sleeve 104 to the bottom stop 124.
Al1-hol~Jh not clearly shown, a hllching is preferAbly inserted into the counter bore 124a to a position between the cable 118 and the ~ottom stop 124.
In practice, there are about 200 different sizes of down hole cable conductors 118, a}though the bottom stop 124 is preferably only one size. For convenience, therefore, field personnel carry a plurality of ring-s~ hl~C~ing6 ha~ing a fixed external diameter to fit within the bottom stop 124, and different incremental sizes of the internal diameter to match the size of the cable 118. After insertion of the proper sized bllchin~, the screw 126 is tightened against the hlls~ing to complete the connection.
In operation, the formation exerts a significant amount of pressure which may be applied against the WO 94125726 PCTrUS93/04032 barrier or wellhead WH. ~he fluld within the well bore forms a fluid column which rises and falls depending upon the formation pressure and whether the down hole pump is turned on or off. When the pump is turned off, the fluid column typically rises causing a high pressure area 130 surro~n~i n~ the connector 23 . This high pressure can reach the pressure rating of the wellhead WH, which could be 5,000 to 10,000 psi or ~ore. In c~ ast, the surrounding air 132 outside the wellhead WH is at relatively low pressure.
Due to the high prescure, t~e male and female boot6 120, 122 typically become saturated with well fluids. When the down hole pump is turned on, it pumps fluid up the production tu~ing 162 typically causing the fluid column to fall, so that the area 130 becomes relatively dc~L. ~~ized. The fluid impregnated male and female boots 120, 122 can not rele~se the fluid fast ~,o-~h, 80 that a pressure differential exists between the inside of the ~o.l~.r~-Lor 23 and the surrounding depressurized area 130. The rubber of the male and female boots 120, 122 tends to ~Yra~ to force the male and female boots 120, 122 apart, which would otherwise separate the male ronn~ctor pin 116 from the female connector socket 114. Due to the top stop 102, the bottom stop 124 and the outer sleeve 104, the rubber boots 120, 122 are confined and can not readily eYr~nd so that the co..~.e~-Lor 23 remains intact.
Further, since the top fitting 100 is fixedly attached to the rigid tube 15 and attached to or integrally formed with the top stop 102, the rigid tube 15 is not forced out of the connector 23, so that the connector 23 remains intact.
Referring now to Figure 11, a partial sectional view of the connector 23 is shown illustrating the stand off 112. As shown, the stand off 112 preferably , ~ " ,. . . .

WO 941~726 PCT~S93/04032 has a larger diameter than the female connector socket 114 for proper placement of the rubber female boot 120.
When the down hole pump is L~L .ed off, any fluid existing in the high pressure area 130 seeps inside the connector 23 and impregnates the male and female boots 120, 122. A low pressure area exists inside the rigid tube 15 relative to the area 130 and the boots 120, 122. The pressurized fluid impregnated rubber of the boots 120, 122 tends to ~YpA~ within the connector 23, thereby forming a tighter seal on all passages through which well fluids might flow. It is undesirable for fluid to escape through the rigid tube 15 via the electrical conductive means 11 co~prising the conductor element portion 11' and the in~ tion 113.
The stand off 112 preferably for~ed of a reenforced, high voltage, high ~LL~ Lh insulator material. The material is preferably a glass-filled material, ~uch as ~estingho~-e G-10, ~or exaople. The stand off 112 has a hole 112a with a diameter for 20 ~ULLO~ ;n7 the in~ulation 113 of the electrical co,.~ Live means 11, and a second, larger diameter hole 112b on one end ext~n~ing part way~ into the stand off 112. The second hole 112b is carefully counter bored to receive the rigid tube 15 to prefera~ly create a tight fit. The second hole 112b also forms an extension lip 112c for circumscribing the rigid tube 15, and a shoulder 112d engaging the lower end 110 of the rigid tube 15. In spite of the high pressure, the rubber of the female boot 120 may extend slightly 30 between the extension lip 112c and the rigid tube 15, ~ut will not penetrate all the way to the shoulder 112d. In fact, due to the pressure applied by the SU~ L ~.ding rubber, and the low pressure within the rigid tube 15, the lower end 110 of the rigid tube 15 is forced into the shoulder 112d of the ~. . . . .

WO 94~5726 PCTrUS931~32 forming an effective fluid seal. The stand off 112 has a relatively wide flat face at a lower end 112e engaging the upper end 114a, which is also relatively wide and flat, forming a fluid seal. The pressure also forces the female connector socket 114 against the lower end 112e of the stand off 112. Thus, fluid will not escape past the stand off 112, allowing for a greater seal.
It is now appreciated that each of the connectors lo 23 for connecting the electrical co~ductor means 10, 11, 12 provides an effective seal preventing fluid from escaping through the rigid tubes ~5, and remain intact during pressurization and depressurization oc~Lences in the well. ~he top and bottom stops 102, 124 attached to the outer sleeve 104 confines the rubber boots 120, 122 and prevents them from ey~n~ing. The stand off 112 includes a shoulder 112d formed around the rigid tube lS to prevent a fluid leak.
Time varying current through a conductive wire typically generates a magnetic field circumscribing the wire. The b~rrier comprising the tubing hanger 8 and flange 16 typically comprise ferromagnetic materials to achieve the required strength without ~Y~Desive ~Yr~n~e. The varying ~ul~ellt through the electrical 25 ron~l~ctor means 10, 11, 12 would typically in~-~ce electrical eddy currents in the tllhing hanger 8 and the flange 16, which is undesirable because the electrical eddy currents ca~se a significant loss of energy due to heating of the wellhead WH. To reduce the electrical eddy currents, multiphase co~uctors are typically grouped together in an attempt to cancel the induced magnetic flux from each conductor with the opposing magnetic flux from the other conductors. This groupin~
of the conductors, however, i~creases the radial .. ~, , .

W O 94125726 ~rrus93104n32 profile of the electrical penetration of the wellhead ~H .
Referring now to Figure 12, a partial sectional front view of the w~llheA~ WH is shown, illustrating the preferred positions of the electrical conduction means 10, 11, 12 penetrating the wellhead WH. From Figures 12 and 2, it is seen that the three rigid tubes 15 passing through the flange 16 and the tubing hanger ~3 are preferably aligned side-by-side defining an arc on a circle preferably having its center located at the center of the wellhead WH, although the present invention is not limited to this particular configuration. Figure 3 shows that the profile of all of the rigid tubes lS are approxi~ately that of a single rigid tube 15, which is desirable since it allows for a reduced radial profile of multiphase conductors penetrating the wellhead WH. Nonetheless, the present invention is not limited to any particular configuration of the rigid tubes 15, 60 that a single rigid tube 15 could be used or ~ultiple rigid tubes 15 could be arranged in any fashion.
In spite of the fact that the electrical conductor means 10, 11, 12 are operated at high voltage to reduce amperage and consequent power losses, significant amounts of sinusoidally varying ~UL~e~ flows through the electrical conductor means 10, 11, 12 in t~ree phase fashion. Without the present invention, high C~LLe~ conductors arranged in this fashion would not cancel the magnetic flux of the conductors, causing heating of the wellhead WH and loss of energy. There has been, however, no measurable rise in the temperature of the wellhead WH, even with power d~ -n~s up to 200 horsepower or more using apparatus according to the present invention. The rigid tubes 15 are 3S preferably formed of a non-ferromagnetic electrically WO241~726 PCT~S9310~32 conductive material, such as for example, stainless steel, which effectively act as eddy ~Le,.~ shunts, so that electrical eddy currents only flow in the rigid tubes 15. Since the currents flowing in the rigid tubes 15 do not produce any significant heat, the wellhq~ WH does not absorb energy nor does it generate heat. Thus, the use of the non-ferromagnetic rigid tube 15 saves energy and eliminates undesirable heating of the wellhead WH.
Referring now to Figure 13 a partial sectional view of the rigid seal means 20 is shown for P~A lAhly securing the rigid tube 15 to the barrier of the wellhead WH. The conduit portion 25 is preferably conn~cted to a ferrule-type fitting 140, such as a Swagelok~ or the like, used to co~ect the conduit portion 25 to the wellhead WH and to the rigid tu~es 15. The ferrule-type fitting 140 comprises a body fitting 142 having a threaded portion 142a for interfacing a threaded hole 16a of the tubing spool 16, thus providing a metal to metal explosion-proof connection. The body fitting 142 slides over the rigid tube 15 and is screwed into the threaded hole 16a. The body fitting 142 has an upper threaded projecting mem~er 142b having a conical counter bored upper end 142c creating a gap between the threaded projecting mem~er 142b and the rigid tube 15.
A ferrule 144, preferably comprising a ring-shaped conical h~ching, has a center hole for fitting around the rigid tube 15 to rest on top of the body fitting 142. The cross-~ection of the ferrule 144 is preferably wedged-shaped, having a wide flat portion 144b at one end, and an opposing narrow end 144a fitting into the gap between the rigid tube 15 and the body fitting 142. The ferrule 144 preferably comprises a hard ~oldahle or marhin~hle plastic type material, .. ~ , ...

and more preferably comprises a polyimide resin, such as Yespel~ by Dupont Co., which has some flexibility to retain its original shape after being deformed. Other heat resistant polymers or moldable powders could be 5 used. Also, polyetheretherketones (PEEK), such as, for example, XYl~ ~eries 450 by E.G.C., Corp., could be molded or marhin~ to form an appropriate ferrule 144.
A nut fitting 146 preferably has a threaded opening 146a for interfacing the threaded projecting member 142b. The nut fitting 146 has an upper opening 146b for slidably fitting around the rigid tube 15. The upper opening 146b is narrower than the threaded op~ing 146a, for~ing an inner sho~ r 146c, for contacting or interfacing with the flat portion 144b of 15 the ferrule 144.
Thus, when the nut fitting 146 is screwed onto the body fitting 142 and over the ferrule 144, the shoulder 146c ~ t the ferrule 144, wedging the ferrule 144 further into the gap. Due to the cross-20 sectional wedge shape of the ferrule 144, it slides against the counter bored upper end 142c, deforming to press Agair~ct the rigid tube 15. ~he ferrule 144 is preferably deformed slightly as the nut fitting 146 is tightened, causing a slight deformation or crimp 148 in 25 the rigid tube 15. The ferrule 144 thus preferably allows a tight connection between the ~ody and nut fittings 142, 146. However, the ferrule 144 is made of a softer material than the material of the rigid tube 15, so that the ferrule 144 does not "bite" into the 30 rigid tube 15. The crimp 148 in the rigid tube 15 pirlt~h~c or cho~es the electrical conductor means 11 to form a fluid seal for preventing any fluid from leaking from the high pressure area 130 inside the wellhead WH
through the rigid tube 15.

WO 94/~726 PCTrUS93t~32 When the nut and body fittings 142, 146 are subsequently removed, the ferrule 144 retains its original shape and can thus be easily removed from the rigid tube 15. In prior designs, a metal ferrule was used, which permanently bit and clamped to the rigid tube 15 when the fitting was screwed together. When the well was pulled, the metal ferrule had to be sawed off or otherwise removed, thereby destroying the rigid tube 15. The ferrule 144 according to the present invention, on the other hand, allows easy removal when the well is pulled. Recall that a similar rigid seal means 20' is provided on the opposite end of the tu~ing hanger 8, for~ing a seal on either end of the wellhead WH. As shown in Fig. 12, however, the lower rigid seal means preferably includes a standard two-pioce metal ferrule to lock the rigid tube 15 in place, preventing axial movement. A ring-ch~e~ ferrule 21a is forced against a conical sh~re~ ferrule 21b to form a metal to metal contact as known to those fikilled in the art.
The upper ri~id seal means 20 using the single ferrule 144 does not nec~sArily function as an axial stop.
Referring now to Figure 14, a pArtial sectional view is shown of a protective cover or sheath, otherwise referred to as the triskelion 150, which protects and separates the individual conductors and also covers the end of the insulation of the down hole cable conductors 118. The triskelion 150 is preferably formed from a non-ferromagnetic electrically con~-lctive material, such as nickel-plated brass or stainless steel, for example, although other similar materials may be used. As described previously, three down hole cable conductors 118 are extended within corresponding rigid tube means forming conductor extensions 24. The conductor extension 24 fits relatively snugly around the down hole cable conductors 118 forming a relatively WO 94/~726 PCT~S93/~32 small annular clearance to pre~ent excessive expansion of the insulation of the down hole cable conductors 118 during !~t - e-surization. The upper ends of the con~t-ctor extensions 24 are terminated at the counter bores 124a as described previously.
The conduc*or extensions 24 are separated near the top of the trickelion 150, but are integrally formed at a mid-point 152 with a single, larger protective sheathing 154, 50 that the down hole cable conductors 118 extend into the sheathing 154. The down hole cable con~ tors llB are ~lG~ed together wit~in the sheathing 154 forming the 3-wire cable 155 bound by protective armor 156, which preferably co~prises coLlu~aLed steel armor ~,o~-,ding the down hole cable co~ r:Lors 118. The 3-wire cable 155 and the protective armor 1~6 extends all the way down the bore hole to protect the down hole cable conductors 118.
The sheathing 154 is preferably flared below the mid point 152 at a location 158, to increase the diameter of the sheathing 154 to cover the ~-ou~ed down hole cable conductors 118 ~nd t~e protective cover 156. The triskelion 150, therefore, covers the end of the cable insulation of the cable 118 and separates the individual down hole cable con~lrtors 118.
It is kno~n that the in~llAtion s~,.ou.. ding the cable conductors 118 saturates with fluid, so that the insulation tends to ~YrAn~ and ~ollL,act during compression and decompression when the down hole pump is turned on ~nd off. In t~is manner, the triskelion 150 prevents damage of the con~ctors and surrounding incnl~tion of the do~n hole cable conductors 118, by preventing the insulation from expanding after decompression. Such ~yp~ncion could destroy the insulation around the conductors, possibly causing an electrical short. The triskelion 150 further provides .. .. .. . .

WO 94~5726 PCTrUS93/~32 a transition from the 3-wire cable 155 down hole su.~o~--d~ by the protective armour 156 to the three single cable conductor extensions 24. The triskelion 150 is axially fixed in position by the clamp means 160 to provide axial column strength to the conductors to maintain vertical elevation of the male connector pin 116 inside the female connector socket 114.
Figure 14A is a cross-sectional view of the triskelion 150 looking along line 14A-14A of Figure 14.
Figures 15 and 15A illustrate an alternative triskelion 150', where the down hole cable con~ctors 118 are prefer~bly aligned side-by-side Analogou~ parts are indicated using identical reference numerals followed by an a~GaLl~he c-ymbol n ~1l . One advantage of the triskelion 150' over the triskelion 150 is that the trickelion 150' has a narrower profile for flat cables.
Referring now to Figure 16, a top plan view of an alternate form of splice fitting, referred to as the splice ~itting 200, is shown with a similar removable cap or cover 202 (Fig. 17) removed. The splice fitting 200 and its coL~ ,o..ling cover 202 are similar and used for similar ~ es as the splice fitting 42 and cover 43. It has been discovered that an appreciable amount of water collects within the splice fittings 42 or 200 due to cQn~nC~tion or other ~eans, so that it is desirable to protect the electrical cor...e~Lion from water. However, if the seal through the barrier of the wellh~a~ WH should fail for any rea_on, ~uch that well fluids travel from the well bore through the electrical conductor means 10, 11, 12 to the splice fitting 200, it is desired to ~le~e.,L the fluids from reaching and penetrating the power electrical conductor means 10a, lla and 12a. If this were to occur, there is an increased likelihood that the well fluids could reach a wo 94!~726 PCTrUS93/0~32 non-hazardous area via the power electrical conductor means 10a, lla, 12a.
The electrical conductor means 10, 11, 12 enter the splice fitting 200 from the wellhead ~H into openings 204 of breather boots 206. The splice fitting 200 includes one or more ~imilar electrical connections ~epen~ing on the num~er of electrical conductor connections required, where there are three connections in the preferred em~odi~ent. The conductor element portions 10', 11' and 12' are exposed within the or~ninqs 204, and are inserted ~hrough gas block seal passages 208 and into ~olL~ on~ing passages 210 of separate splice connectors 212. The splice connectors 212 preferably comprise an electrically conductive material such as cG~ L or the like. The breather boots 206 include cavities 214 for placement of the splice connectors 212. The power electrical conductor means 10a, lla, 12a enter the opposing or power side end of the splice fitting 200 into power conductor Z0 passages 216 of the breather boots 206. The power conductor element portions 10a', lla' and 12a' of the power electrical con~ctor means 10a, lla and 12a, ~e_~e~Lively, are ~YpOs~ and inserted into co~le~ ;ng passages 218 on the opposite side of the splice connectors 212.
Referring now to Fig. 17, a sectional side view of the splice fitting 200 is shown with the cover 202 attached. Only the conne~tion for the electrical conductor means 10a and 10 is shown, it being understood that the connections for the other electrical conductor means lla, 12a and 11, 12 are made in a similar manner. Two threaded holes 220 and correspon~ing screws 222, preferably allen-type screws, are provided for securing the conductor element portion 10' to the splice conn~ctor 212. In a similar manner, WO 94l25726 PCTrUS9310~32 two threaded holes 224 and corresponding screws 226, preferably allen-type screws r are provided for securing the power conductor element portion lOa' to the splice connector 212.
The breather boot 206 preferably comprises rubber, or any other suit~ble material for providing electrical insulation and to seal the electrical connection from per.eLLation by water. The breather passage 204, however, includes a breather passage 205 along the electrical conductor means 10, which would otherwise allow fluid communication within the breather boot 206.
Furthermore, the insulation 113 of the electrical conductor means 10 does not extend into the opening 204 all the way to the gas block seal passage 208, leaving a he~r space 228 between the insulation of the electrical conductor means 10 and the gas block seal pAcs~ge 208. The purpose of the breather passage 205 and the gas block seal passage 208 will be described ~elow.
Referring now to Fig. 18, a sectional side view of the splice fitting 200 is shown illustr~ting the position of the splice fitting 200 to make the electrical connection. The breather boot 206 is preferably slid onto the electrical conductor means 10, exposing the splice connector 212. Any suitable instrument, such as an allen wrench or driver 230, may be employed to secure the screws 222, 226 of the splice connector 212 to complete the electrical connection.
The breather boot 206 is slid back into place as shown in Figs. 16 and 17, and the breather passage 204, as well as the header space 228, are filled with a silicone compound or the like, to seal the connection from water penetration. The silicone compound preferably has a grease-like viscosity to protect against water vapor. Furthermore, the silicone ~., .. ~ .

WO 94/~726 PCT~S93/0~32 compound preferably has a relatively low viscosity for silicone, but high temperature viscosity stability to remain at a relatively low to medium viscosity at temperatures of about 200~F. Also, the silicone compound preferably has a high dielectric strength to achieve good electrical insulation.
Under normal conditions, the silicone compound remains in the header space 228 and the breather passage 205 until the electrical connection is removed or otherwise taken apart. However, if the seal within the bore hole should fail, so that well fluids escape through the electrical conductor mean 10 to the splice fitting 200, down hole pressure is exerted to remove the silicone co~und from the h~ r space 228 and the breather passage 205. The silicone compound functionally cooperates with the breather boot 206, 50 that the silicone ~ ~l ~ is displaced ~y well fluids from the well via the electrical conductive means 10 at a lower.pressure than that re~uired to penetrate the gas bloc~ seal passage 208 to, and around the splice connector 212, and to the power electrical conductor means lOa within the breather boot 206. This allows the well fluid to escape into the splice fitting 200.
As described for the splice fitting 42, there is no gasket between the splice fitting 200 and the cover 202 to permit the discharge of well fluids to the s~ ~oul,ding atmosphere. Thus, the well fluids are not communicated to the power electrical conductor means lOa, which could otherwise com~unicate the well fluids to a non-hazardous area.
Figure 19 is a more detailed partial cross-sectional and reversed view of an electrical connection within a breather boot 206.
Figs. 2OA-2OF are cross-sectional vlews of the electrical connection of Fig. 19, looking along lines WO 94l~726 PCT~S93/0~32 20A-20A, 20B-20B, 20C-20C, 20D-20D, 20E-20E and 20F-20F, respectively. Fig. 20A illustrates the breather p~c~-~e 205 more clearly. Fig 20B illustrates the header space 228. Fig. 20C illustrates that the gas block seal passage 208 surrounds and seals the electrical conductor portion lo'. Fig. 20D illustrates the physical isolation between the power conductor element portion lOa' and the conductor element portion 10' within the splice connector 212. Fig. 20E
lo illustrates the screws 226 screwed into the splice connector 212 to secure the power conAuctor element portion lOa'. In a similar manner, the screws 222 are used to secure the conductor element portion 10' to the splice connectors 212. Figure 20E illustrates the power electrical conductor means lOa entering and ffealed by the breather boot 206. It is noted that the power electrical conductor means lOa is preferably a Underwriter's Laboratories (UL~ listed 5 KV stranded wire w~th inc~ tion 240 circumscribed by a jacket 242, although it is not limited to any particular type of conductor.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in size, shape and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

Claims (4)

Claims:

1. A protective sheath for protection and separating a plurality of insulated cable conductors from a single cable that includes a layer of protective armor surrounding all the conductors extending from down hole along production tubing in an underground well, wherein the protective armor terminates at a separating point of the cable conductors so that the plurality of cable conductors are separated into individual cable conductors, said sheath comprising:
a hollow rigid tube for enclosing the plurality of insulated cable conductors and protective armor; and a plurality of individual rigid tubes integrally formed to and enclosing one end of said rigid tube so that each one of the plurality of cable conductors is routed into a separate rigid tube wherein each one of said plurality of rigid tubes encloses a corresponding one of the individual cable conductors;
the rigid tube and individual rigid tubes being sized to confine but not sealingly engage the conductors when the well is pressurized for preventing excessive expansion of the insulation on the conductors during well depressurization.

2. The sheath of claim 1, wherein said hollow rigid tube and said plurality of individual rigid tubes comprise a non-ferromagnetic electrically conductive material.

3. The sheath of claim 1, wherein said hollow rigid tube and said plurality of rigid tubes are formed of nickel plated brass.

4. The sheath of claim 1, further comprising:
means for attaching the sheath to the production tubing.