US2128716A - Well testing device - Google Patents

Description

2 sheets-sheet 1 Aug. 30, '1938. T. N. SMITH 4 WELL TESTING DEVICE Filed Nov. 2, 1957.

ug. 30, 1938. T. N. SMITH WELL TESTING' DEVICE 2 Sheets-Sheet 2 Filed NOV. 2, 1937 Patented Aug. 30, '19385v Y y. v I

UNITED STATES PATENT OFFICE l alzsmc WELL TESTING DEVICE Thomas Noah smith, san Antonio, Tex. Application Nqvember z, 1937, serial No. 112,431

` sI claims. (c1. 16s-1) This invention relates to well testers for use in Fig. 2 is a central longitudinal section through testing a well preferably of the gas and oil type, the device, showing the same in a seated position to determine whether a producing stratum has in a formation to be tested; y l been reached. Fig. 3 is a fragmentary view showing the jawed Up until recently, the commonly accepted members at the zone where the packer body and 5 method used for testing wells involved considerthe' drill stem meet, in the position at the time able labor and expense and quite frequently rethe device is being lowered into the well;

suited in destroying the well.v It generally in-v Fig. 4 is a fragmentary view at the same zone volved thesettlng of well casing and a screen toof the same parts, in the position where the gether with the work of cementing the well bepacker body is seated, in the formation; l0

fore the test could be made. The well then had Fig. 5 is a fragmentary vertical section showing to bewashed and tested and if it was found that a modification of the packer in a'position before no producing formation had been reached, the seating;

liner, screen, wash pipe and related equipment Fig. 6 is a fragmentary vertical section of the had to be removed, so that the well could be modification shown in Fig-5 but in the position l5 drilled further into another stratum. Seldom, if `after seating;

ever, was the' screen recovered in a condit on Fig. 7 is a perspective view, partly in section,

where it could be used again because of the` act showing the packer removed from the device; and

that'it had been so firmly anchored. Fig. 8 is a modification of the valve means It is an object of this invention to provide a shown in Figs. l and 2. 20

device which can be quickly introduced into the This tool is intended for use in the rotary syswell to make a test of the formation and then tem of drilling wells, wherein the work of proagain easily withdrawn, all with a. minimum exducing ahole is done by a bit attached to the penditure of time and money. f y end of a tubular drill stem. The drill stem is 25. A particular object of the invention is to prorotated by a rotary, the connections between the 25 vide means whereby the tool may be seated in drill stem and the rotary being such that the the bore hole and lpacked oi before the valve is drill stem may be fed downwardly while, at the opened, so that aproper seat is assured and the same time, it is being rotated. Simultaneously uid below the packer is shut off before the valve with the rotary and downward motion of the bit,

` is opened. drilling fluid. or mud, is .pumped downwardly 30 Still another object of the invention is to prothrough the drill stem, this iluid emerging from vide valved means above the packer for setting ports, or water courses, in the bit. After thev up a circulation of ushing uid down through drilling iiuid leaves the blt it travels upwardly. the string of pipe and up the outside thereof, through the space between the drillstem and the equalizing pressures and thereby causing a back well wall to the surface, where it is stored in a 35 pressure to force the liquid or gasback in ordr- "slush pit for use again. This drilling fluid to prevent a blow out, a very serious but not comserves to `coo1 the cutting edges of the bit; to remon happening when testing wells at different move cuttings made bythe blt;v and to prevent,

strata, Y so far as possible, blowouts which might occur Yet another object is to provide a novel form when high pressure formations are encountered. 40

' and construction for the packer employed. Since the well is full of this drilling fluid at A further object of the inventfonfisto provide a all times, it is clear-that the static pressure .at valve means provided with iiuid ducts, so deany given point in the well is dependent uponsigned that the fluid issuing therefrom` under the head of the fluid above that point. Usually,

high pressure and containing particles of foreign therefore, in deep well drilling the static pressure 45 matter will not have a tendency to erode the in the well is sufficient to prevent blowouts. valve seat. But the static pressure also has its objections.

A still further object of the invention is to pro- One of them is that oil or gas bearing strata vide a testing tool in which the parts are so demight -be passed without the driller having knowli signed and arranged as to make for ease in asedge of this. This is because the static pressure 50 sembly, economy in the cost of manufacture and of the drilling fluid serves to prevent the entrance simplicity and efficiency in operation. g of gas or oil into the hole unless the gas or oil Referring to the drawings: s is under sulcient Ipressure to enter the well Fig. 1 is a central longitudinal section through against the static pressure... 55'` the device embodying the invention; In order to eliminate the possibility of passing 55 smaller hole is known tothe operator as a rat ho1e, and the shoulder of thlsghole furnishes a. sealing means for sealing oi the static pressure of the well from the rat hole while' the device rests on the shoulder and the test is being made.

Upon the shoulder casing may also be set, should production be discovered in the small rat hole. The rat hole is usually cored' in`by one crew yof workmen.. 'I'he next crew reams down, leaving a full-gauged hole to'bottom, ready for the next crew to, begin rat-heling or core drilling again. 'I'he core obtained in the rat hole operation gives the driller an accurate log o1'- the well and also gives him an indication of when oil or gas formation is reached.

After drilling the rat hole the entire string of drill stem is removed from the well and the bit is replaced by the testing tool. The bit is removed from the hole during testing. The valve of the testing'tool is: held in Aa closed position during the time the tool is being lowered; consequently the inside of the drill stem contains no iiuid and for this reason there is no static pressure in the drillstem. Invother words, the well is full of drilling iluid but there is none in the drill stein.A

Afterthetesting tool has been seated on the shoulder ofthe rat hole and the static pressure from Vthe hole above has been sealed oiI from the rat hole, the valve in the testing tool is opened thereby relieving the formation being. tested of all static pressure.- Any oil or gas in thejstrata being tested willnow` enter'the rat hole, pass through the valve of the testing tool and into the drill stem, thus furnishing a sample `of the producing capacity of that particular strata.

On removing the tool from its seat the valve is again closed, thereby retaining the fluid which has entered during the test, vuntil the tool is raised to the surface.v

'I'he device of Fig. 1 is intended to be secured to the lower end of a hollow drill stern I by means of the threads shown or, a standard A. P. I. drill stem tool joint or coupling (not shown). and inserted downwardly into the well within the casing 2. The hollow drill stem serves to control and operate the testing device. length section 3 constituting a sample retaining chamber, has formed therein a flared mouth l and is formed with screw threads 5 to which is adapted to be secured the valve housing 8,' said housing having a valve seat 'l upon which is adapted to seat a valve 8. Y

'I'he valve. is housed,l as shown. the valve stem4 Shaving a sliding ilt therewith and being pro- .vided throughout its lower extremity with threads ,l 0, securing the packer body proper I I to the valve housing Il. v

The valve housing is provided with a downwardly depending guide I5, adapted to t vwithin and slide with respect to a guide I 8 formed on the packer body proper. y

A helical spring I1, ofthe proper tension, is

placed within the recess formed by the guide I5 and surrounds the valve stem 9, as shown, said spring aiding in keeping lthe parts 6 and II apart -while the device is being lowered into the valve.

The valve stem has a longitudinal bore 20 therein, extending throughout its length,`fsaid bore The nipple orl short communicating with a plurality of horizontal openings 2l, which openings lead to a recess 22 formed in the valve housing and directly below the valve seat 1 and valve 8.- 'Ihe lower portion of the bore 20 has screwed therein a choke plug 25 which is provided with passage 26, said passage in turn communicating with passagesor fluid inlet openings 213 and 28 in the bull plug or strainer 30, which depends from the valve stem 9 and is separated'frni the packer body proper by lock washer 3 I.

'I'he packer body proper II is shaped as shown, provision being made for a plurality of superimposed layers of packing material 35, suitably, secured to the packer.body by any well known means. The packing material is made of rubberized material or of leather belting. One of the Afeatures ofthe packer body is that, due to the square shoulder 36, it can easily be seated on soit or hard formations, without forcing said formations outwardly.. 'I'heshoulders 36 seat on the shoulders 31 of the rat hole 38. Frictional resistance between the packing material and the formation se'at will prevent rotation of the packer body. Turning now to Fig. 1, and particularly to the portion marked A, one views the tool in which the relative positions of the cams, spring and valve when entering'or leaving the well, lare shown. Fig. 3 should also be considered in connection with Fig. 1, since this shows the cam arrangement at the portion marked A. In Figs. 1 and 3, the cani arrangement or jaws are shown in a closed position. The jaws, dogs, or cams 40 and 4I, there I ing the valve 8 against the static pressure of the well and preventing the entrance of drilling fluid into the drill stem. In Fig. 1, the static pressure in the wellv acts against the area of the valve 8 which. except for theforce exerted by the spring I1, would cause the valve 48 to open. Drilling 'fluid would then enter the drill stem and ruin any test that has been taken. In removing tests vof very 'deep wells where the force exerted by the spring I1 is not great enough to hold the valve 8` against its seat 1, the drill stem may be rotated to a partial turn before raising the packer of! of its seat, bringing the raised portions of the jaws or `cams in line and closing the valve 8. I'he relative positions of the parts while making the test are shown in Figs. 2 and 4 and the jaws or cams lll and 4I are as shown at the portibn B of Fig. 2.

After the testing tool has been seated on the shoulder of the rat hole and the static pressure from the hole above has been sealed of! from the rat hole, the-valve 8 is opened by rotating part 5 clockwise with respect to part I I, so that the Jaws or cams take the position shown in Fig. 4, thereby relieving the formation being tested of all static pressure. Any oil or gas being tested will enter the rat'hole, pass through the stem of valve 8 and into Ithe drill stem, above valve 8, thus furnishing a sample of the producing capacity of thewell.

The direction of rotation ofthe drill stem for the opening and .closing operations of the. valve vis always clockwiseor in the same direction.

This is important-'since the joints composing the drin stem erejoied together with rightr hand threads. Any rotation inthe reverse direction might cause the threads and joints to loosen;

The reason the square shoulder of the packer.. is provided, Vis manifest.

seated on the shoulder -of the rat hole, the en WhenI the packer is tire weight ofthe drill-stem is allowed'to rest on-the packer. If an angular form 'of packeris `employed,as is common in the art, this great weight causes the packer to be wedged into the rat hole so `tightly that it is very diiilcult to remove the packer. The wedging action is eliminated by using a square shouldered packer.

In the modification shown in Fig. 7, the packer body is designated as 55 and is composed of a metal supporting member surrounded by arubber composition member 56, shaped as shown. Any desired iibrous composition might be used instead of the rubber composition', to suit individuei conditions. As shownthe lower end of- Y annular row of spaced perforations 59 and that the annular flange 59 -is located nearer to the upper portion ofthe member 55 than it is to the lower portion thereof. This assures igreater resiliency to the material 56 .below the flange 59. The material 56 encompassesthe iiange 59 and is also worked into the. perforations 6d.'

Another object in locating the flange 59 as shown, is that, in removing the packer from its seat, the pull of the flange 59 will tend to elongate the member 55 and thereby `reduce its diamet'er'. vIt is clear that this vaction will aid great- 1y the removal of 'the packer from its seat. Obviously, the packer here shownA will not wedge in the upper end of the rat hole, 'and even though in slome. of the softer formations the packer should sink below the surface of the rat hole, land have a tendency to stick, the pull applied to the packer in removing it from the seat will cause the same to elongate and reduce the diameter thereof, thereby releasing the packer from the hole. The member 55 is held to the valve stem 9 andthe threads l0 by means of the nut 51.

In the modification of the valve member, shown 'in Fig. 8, passages 65 near the upper end of the valve stem 9, and just under the valve 8, are provided. These passages are upwardlyfand outwardly directed and communicate with the bore 20. The object in providing these passages is to prevent the' iiuid which enters the testing l high pressure and contains bits of sand and foreign matter, will rapidly vcut any valve or valve seat with which it comes Ain contact. 'I'he pasvice it is only necessary to start the mud pumps at the surface and apply pressure through the column of drilling'fluid inside the drill stem which in turn will cause valve 50 to open, equalizing the pressures onboth the column of uid inside of the drill stem land on the outside of the drill stem, causing a back pressure and forcing the uid or gas back into the well, to prevent what is known as a blowout.l v i Other advantages, besides those mentioned, of the construction, will -be apparent to those skilled in the art.

1. In a device of ,the character described including a drill' stem, a nipple constituting a same ple retaining chamber, a valve housing secured to said nipple, a valve at the upper end of said valve housing `and having a downwardly depending valve stem to which is secured a packer, said packer being slidable with respect to said vvalve housing, said packer andhousing being provided with cooperating cammed surfaces whereby said valve can be moved away from its coacting .valve seat when said drill stem is rotated in one direction only with respect to said packer.

2. In a device of the character described including a drill stem, a nipple constituting a sample retaining chamber, a valve housing secured to said nipple, a valve at the upper end of said valve housing and having a downwardly depending valve stem to whichis secured a packer, said packer bein-gl slidable with respect to said valve housing, a spring surrounding said valvestem and normally urging said valve housing and said packer away from each other, said packer and housing being provided with cooperating cammed .sur-faces whereby said valve can be moved away from its coacting valve seat when said drill stem is rotated in one direction only with respect to said packer. v

3. In a device of the character described including a drill stem, a nipple constituting a sarn- A ple retaining chamber, a valve housing secured tosaid nipple, a valve at the upper end of said valve housing and having a downwardly depending hollowvalve stem to which is secured a packvalve stem and normally urging said-valve housing and said packer away from each other, said valve being adapted to move to its seat when said cammed surfaces are disengaged and from its seat when said cammed surfaces are engaged and when said drill stem is rotated in one direction only with respect to said packer, whereby uid is allowed to enter the, lowerA end of said hollow valve stem and pass above said valve. s

4. In a device of the character described including a drill stem, a nipple constituting a sample retaining chamber, a valve housing'secured to said nipple, a valve at the upper end of said valve housing and having a downwardly depending hollow valve stem to which is securedv a packer, said packer being slidable with respect to said valve housing, said packer being provided with cammed surfaces contacting cammed surfaces on said valve housing, said packer being provided with square shoulders for engaging the 1 upper ,portion of a rat hole in a well, said valve stem having a perforated lug screwed on the lower end thereof and engaging said packer and adapted to project down into the rat hole, a spring surroundingsaid valve stem and normally urging said valve housing and said packer away from each other, said valve being adapted to movel to its seat when said cammed surfaces are disengaged and from its seat when said cammed surfaces are engaged and when said drill stem is rotated in one direction only with respect to saidA ible packer rests on said rat hole, -said cupped packer, whereby iiuld is allowed to 'enter the lower end of said hollow valvezstem and pass above said valve.

5. In. a device ofthe character described for testing formations in oil wells, in which the well is provided with the usual bore and rat hole, a substantially cylindrical compressible packer mounted on a packer body secured to the valve stem of said device, said packer having substantial depth lengthwise of said valve stem and having a diameter greater than said rat hole and less than said bore hole, the lower face of said packer beingcupped so that when said device is lowered into said well for testing and said compresslbeing embedded in said cylindrical plug, the lower face of said compressiible packer being cupped.

" THOMAS NOAH SMITH.

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