OTC 7891 New Tool Designs For High Rate Gravel Pack Operations
OTC 7891 New Tool Designs For High Rate Gravel Pack Operations
OTC 7891 New Tool Designs For High Rate Gravel Pack Operations
OTC 7891
New Tool Designs For High Rate Gravel Pack Operations
Colby M. Ross, P.E., HalliburtonEnergyServices
ABSTRACT
l?eferencas
andillustrations
atendofpaper.
217
NEWTOOLDESIGNS
FORHIGHRATEGRAVELPACKOPERATIONS
218
OTC 7891
CONVENTIONALTOOLSYSTEMS
OTC 7891
COLBYM. Ross
MULTI-POSITION
TOOLSYSTEIIAS
219
NEWTmL DESIGNS
FORHIGHRATEGRAVELPACK
OPERATIONS
OTC 7891
MODIFICATIONS
Most small-size-casing gravel pack tools currently in
use require redesign to sustain higher flow rates. The
newly designed frac pack setting and service tools
incorporated the following modifications:
[ce Tool
Removal of the seals that normally seal in the
packer bore to allow return flow.
Replacement of the seal mandrels with a smaller
OD service tool mandrel.
Replacement of the concentric tube crossover with
a single tube ported flow sub that has elongated
flow slots (Figure 4).
FRACPACKTOOLSFOR SMALL-DIAMETER
CASING
At times, drilling problems can compromise the use of
7-inch or larger casing, and smaller casing must be
used. The operational limits of the available gravel pack
tool systems were particularly restrictive when small
size tubulars were considered . For example, the
maximum rate limitation of 8 bbl/min was insufficient for
some completions. The need to find solutions for the
problems relating to casing sizes of less than 7 inches
motivated further investigation, which resulted in the
conception of the newest improvement to gravel
packing tool technology.
I
These changes provided an increased through bore and
increased exit port slot areas.
220
OTC 7891
COLBYM. Ross
200
175
150
~25
Velocity (f/see) =
:
G
g 100
>
or
Velocity (f/see)=
75
50
TESTING
A series of tests were run on both the standard 5-inch
25
15
w sub Ass@
l~e flow sub below the packer is considerably different
in design. The traditional flow sub flow ports were
replaced with a crossover mandrel. The mandrel
provides slurry exit ports and a return flow bypass
Two stages were pumped for each tool tested. The first
with water and the second with a gelled sand slurry of
approximately 15 Ibm/gal. Stages were performed as
follows:
221
NEWTOOLDESIGNS
FORHIGHRATEGRAVELPACKOPERATIONS
OTC 7891
TABLE 2
Water Stage
Rate (bbl/min)
VOI(bbls)
- 225%
erosion rate @10 bbl/min
(10)2
Sand Stage
Rate (bbl/min)
VOI(bbls)
150
10
150
15
150
al
X!iQ
222
CASEHISTORY
A gulf coast operator who had been involved in the
initial request for a high rate tool in 5-1/2-inch casing
ran the initial job. Previous jobs run by this operator had
been done with conventional tools at lower rates or as
standard fracturing operations, followed by prepacks. In
the latter case, the additional trip required for fracturing
was not cost effective. The zone of interest ran from
8,210 to 8,267 feet. The screen, flow sub, packer and
service tool assembly was run and set. Normal
preparation of the work string was performed, followed
by an initial pad of 72 barrels of 10% HCI followed by 59
barrels of gel. This was pumped ahead of the proppant
slurry.
During the gravel pack operation, a total of 6,700 Ibm of
ceramic frac beads were pumped around the screen
and into the formation. The annular capacity of the
OTC 7891
COLBYM. Ross
ACLNOWLEDGEMENTS
The author wishes to thank the management of
Halliburton Energy Services for their support in
development of these tools and particularly J.D.
Hendrickson for his help, both in testing the tools and in
coordinating this paper.
REFERENCES:
1.
R. D.:
Offshore Hydraulic Fracturing Technique, JPT,
CONCLUSIONS:
In addition to the increased productivity that can be
realized from performance of the fracturing and gravel
packing operations simultaneously, the operator can
benefit from advantages such as 1) the elimination of
one trip into the well, 2) reduction of formation exposure
time, which minimizes fluid loss through the created
fractures, and 3) reduction of subsequent fluid-loss
cleanup time.
TRIC Conversion
bbl x
ftx
F
psi x
lbf X
lbm x
in X
ft3 x
1.589873
.~8*
(F - 32)/1.8
6.894757
4.448222
5.535924
2.54*
2.831685
223
FACTORS
E+ 03 = mz
E-01
=m
= c
E + 00 = kPa
E+ (IO =N
E -01 = kg
E+ OO=cm
E- 02 = m3
GRAVEL PACK
SERVICE SEAL UNIT
CONVENTIONAL CROSSOVER
POSITIVE INDICATOR
WASH PIPE
PRODUCTION SCREEN
BRIDGE PLUG
Figure 1
Conventional Single Zone
Gravel Pack Assembly
224
ELONGATED
FLOW
PORTS
~~l.TRRY
PORTS
RETURN
FLOW
Conventional Cross-Over
Weldment
Figure 2
225
-.
.
1
--E%
SERVICE TOOL
CROSSOVER
FLOW SUB
VIEW B
\
VIEW A
LOWER SEAL
BORE
POF
GRAVELPACK
PACKER
PACKER
BORE/SERVICETOOL
FLOW ANNULUS
RETURN FLOW
FROM SCREEN
SHEAR SUB
Fiaure 3
Circulation Paths torHigh Rate Frac Pack Tool
226
RETURN FLOW
SLURRY EXIT
PORTS
RETURN FLOW