Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR FRACTURING OF OIL AND GAS WELLS
BACKGROUND
[00011 This disclosure relates to a fracturing system and method for acquiring
oil and gas.
[0002] The demand for natural gas and oil has significantly grown over the
years making low
productivity oil and gas reservoirs economically feasible, where hydraulic
fracturing plays an
important part in these energy productions throughout the world. For several
decades different
technology has been used to enhance methods for producing resources from oil
and gas wells.
Long horizontal wellbores with multiple fractures is one commonly used process
to enhance
extraction of oil and gas from wells. This process starts after a well has
been drilled and the
completion has been installed in the wellbore. Multi-stage hydraulic
fracturing is a method that
involves pumping large amounts of pressurized water or gel, a proppant and/or
other chemicals
into the wellbore to create discrete multiple fractures into the reservoir
along the wellbore.
[0003] One of the technologically advanced methods being used today is
simultaneous proppant
fracturing of up to thirty fractures in one pumping operation. This method
involves usage of
proppant to prevent fractures from closing. However, this practice can usually
cause an uneven
distribution of proppant between the fractures, which will reduce the
efficiency of the fracture
system. As a result, this practice can also cause fractures to propagate in
areas that are out of the
target reservoir. Thus, such method can be inefficient and unsafe.
[0004] Additionally, proppant fracturing usually involves multiple steps and
requires several
tools in order to be performed successfully. Such practice that will allow
even distribution of
proppant between fractures highly depends on setting, plugs between the
fracture stages or using
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frac balls of increasing sizes. In these methods, plugs are either set after
each fracture has been
perforated and pumped, or frac balls are dropped from the surface to
successively open
fracturing valves placed along the well. For each stage, balls of different
diameters are dropped
into the well corresponding to a specific fracturing valve's seat. At a point
in the well, the ball
will no longer pass through due to a decrease in well diameter. Once the ball
is in place,
fracturing can take place. After fracturing, the plugs must be drilled out and
the balls must be
recovered. With each fracturing stage while setting plugs, much time and
energy is expended in
tripping out of the hole between the stages and drilling out the plugs.
Moreover, land-based rigs
are usually rented per day basis, and so any delays can be quite expensive.
Also, only about 12
different fracture stages are possible with the ball method before a
restriction in flow area due to
small ball diameter, which makes fracturing difficult due to large pressure
losses.
[0005] As such it would be useful to have an improved system and method for
fracturing oil and
gas wells.
SUMMARY
[0006] This disclosure relates to an improved system and method for fracturing
a well. In one
embodiment, the system can comprise a base pipe comprising an insert port
capable of housing a
stop ball partially within the chamber of the pipe and a sliding sleeve. The
sliding sleeve can
comprise a first sleeve with an in inner surface. That inner surface can
comprise a void. The
first sleeve can be maneuverable into two positions. In the first position,
the void can rest on a
surface of the base pipe not comprising an insert port. Such positioning can
prevent a stop ball
from exiting the chamber of the base pipe. In the second position, the void
can rest over the
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insert port. Such positioning can allow the stop ball into the chamber of said
base pipe and to
enter the void.
[0007] In another embodiment, the method can comprise connecting a base pipe
within a pipe
string. The base pipe can comprise an insert port capable of housing a stop
ball, with the stop
ball partially within the chamber of the base pipe. The method can also
include the step of
actuating a sliding sleeve from a first position to a second position. The
sliding sleeve can
comprise a first sleeve that has an in inner surface with a void. In the first
position, the void can
rest on a surface of said base pipe not comprising said insert port,
preventing said stop ball from
exiting the chamber of said base pipe. In the second position, the void can
rest over the insert
port. Such positioning can allow the stop ball to exit the chamber of said
base pipe, to enter said
void.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1A illustrates a side view of a base pipe.
[0009] Figure 1B illustrates a cross-sectional view of a base pipe.
[0010] Figure 1C illustrates a cross sectional view of a base pipe.
[0011] Figure 2A illustrates a sliding sleeve.
[0012] Figure 2B illustrates a cross-sectional view of a sliding sleeve.
[0013] Figure 2C illustrates a cross sectional view of a sliding sleeve.
[0014] Figure 2D illustrates a cross sectional view of a sliding sleeve.
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[0015] Figure 3A illustrates a peripheral view of outer ring.
[0016] Figure 3B illustrates a cross-sectional view of an outer ring.
[0017] Figure 4A illustrates a valve casing.
[0018] Figure 4B illustrates a fracturing port of a valve casing.
[0019] Figure 4C illustrates a production port of a valve casing.
[0020] Figure 5 illustrates a fracturing valve in fracturing mode.
[0021] Figure 6 illustrates an impedance device in between fracturing port.
[0022] Figure 7 illustrates fracturing valve in production mode.
DETAILED DESCRIPTION
[0023] Described herein is an improved fracturing system and method for
acquiring oil and gas.
The following description is presented to enable any person skilled in the art
to make and use the
invention as claimed and is provided in the context of the particular examples
discussed below,
variations of which will be readily apparent to those skilled in the art. In
the interest of clarity,
not all features of an actual implementation are described in this
specification. It will be
appreciated that in the development of any such actual implementation (as in
any development
project), design decisions must be made to achieve the designers' specific
goals (e.g.,
compliance with system- and business-related constraints), and that these
goals will vary from
one implementation to another. It will also be appreciated that such
development effort might be
complex and time-consuming, but would nevertheless be a routine undertaking
for those of
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ordinary skill in the field of the appropriate art having the benefit of this
disclosure. Accordingly,
the claims appended hereto are not intended to be limited by the disclosed
embodiments, but are
to be accorded their widest scope consistent with the principles and features
disclosed herein.
[0024] Figure IA illustrates a side view of a base pipe 100. Base pipe 100 can
be connected as a
portion of a pipe string. In one embodiment, base pipe 100 can be a
cylindrical material that can
comprise different wall openings and/or slots. Base pipe 100 wall openings can
comprise insert
port 101, fracturing port 102, and/or production port 103. Insert port 101 can
be made of one or
more small openings in a base pipe 100. Fracturing port 102 can also be made
of one or more
openings. Further, production port 103 can be a plurality of openings in base
pipe 100.
[0025] Figure 1B illustrates a front view of base pipe 100. Base pipe 100 can
further comprise a
chamber 104. Chamber 104 can be a cylindrical opening or a space created
inside base pipe 100.
As such chamber 104 can be an opening that can allow material, such as frac
fluid or
hydrocarbons to pass through. Figure 1C illustrates a cross sectional view of
a base pipe 100.
Each wall opening discussed above can be circularly placed around base pipe
100.
[0026] Figure 2A illustrates a sliding sleeve 200. In one embodiment, sliding
sleeve 200 can be
a cylindrical tube that can comprise fracturing port 102. Thus, fracturing
port 102 can have a
first portion within base pipe 101 and a second portion within sliding sleeve
200. Figure 2B
illustrates a front view of a sliding sleeve 200. Sliding sleeve 200 can
further comprise an outer
chamber 201. In one embodiment, outer chamber 201 can be an opening larger
than chamber
104. As such, outer chamber 201 can be large enough to house base pipe 100.
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[0027] Figure 2C illustrates a cross sectional view of a sliding sleeve 200.
Sliding sleeve 200
can comprise a first sleeve 202 and a second sleeve 203. First sleeve 202 and
second sleeve 203
can be attached through one or more curved sheets 204 with the spaces between
each curved
sheet 204 defining a portion of fracturing port 102. Inner surface of first
sleeve 202 can have a
bottleneck void, or any other void within the inner surface. The void can
extend radially around
the complete inner diameter of base pipe 101, partially around the inner
diameter, or locally. If
completely around the inner diameter, the ends of inner surface can have a
smaller diameter than
the void.
[0028] Figure 2D illustrates a cross sectional view of a sliding sleeve 200.
Sliding sleeve 200
can further comprise a fixed sleeve 205, and actuator 206. In one embodiment,
actuator 206 can
be a biasing device. In such embodiment, biasing device can be a spring. In
another
embodiment, actuator can be bidirectional and/or motorized. In one embodiment,
second sleeve
203 of sliding sleeve 200 can be attached to fixed sleeve 205 using actuator
206. In one
embodiment, sliding sleeve 200 can be pulled towards fixed sleeve 205, thus
compressing, or
otherwise storing, load actuator 206 with potential energy. Later actuator 206
can be released, or
otherwise instigated, pushing sliding sleeve 200 away from fixed sleeve 205.
[0029] Figure 3A illustrates a peripheral view of outer ring 207. In one
embodiment, outer ring
207 can be a solid cylindrical tube forming a ring chamber 301, as seen in
figure 3B. In one
embodiment, outer ring 207 can be an enclosed solid material forming a
cylindrical shape. Ring
chamber 301 can be the space formed inside outer ring 207. Furthermore, ring
chamber 301 can
be large enough to slide over base pipe 100.
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[0030] Figure 4A illustrates a valve casing 400. In one embodiment, valve
casing 400 can be a
cylindrical material, which can comprise fracturing port 102, and production
port 103. Figure
4B illustrates fracturing port 102 of valve casing 400. In one embodiment,
fracturing port 102
can be a plurality of openings circularly placed around valve casing 400, as
seen in Figure 4B.
Figure 4C illustrates production port 103 of valve casing 400. Furthermore,
production port 103
can be one or more openings placed around valve casing 400, as seen in Figure
4C.
[0031] Figure 5 illustrates a fracturing valve 500 in fracturing mode. In one
embodiment,
fracturing valve 500 can comprise base pipe 100, sliding sleeve 200, outer
ring 207, and/or valve
casing 400. In such embodiment, base pipe 100 can be an innermost layer of
fracturing valve
500. A middle layer around base pipe 100 can comprise outer ring 207 fixed to
base pipe 100
and sliding sleeve 200, where fixed sleeve 205 is fixed to base pipe 100.
Fracturing valve 500
can comprise valve casing 400 as an outer later. Valve casing 400 can, in one
embodiment,
connect to outer ring 207 and fixed sleeve 205. In a fracturing position,
fracturing port 102 can
be aligned and open, due to the relative position of base pipe 100 and sliding
sleeve 200.
[0032] Fracturing valve 500 can further comprise a frac ball 501 and one or
more stop balls 502.
In one embodiment, stop ball 502 can rest in insert port 101. At a fracturing
state, actuator 206
can be in a closed state, pushing stop ball 502 partially into chamber 104. In
such state, frac ball
501 can be released from the surface and down the well. Frac ball 501 will be
halted at insert
port 101 by any protruding stop balls 502 while fracturing valve 500 is in
fracturing mode. As
such, the protruding portion of stop ball 502 can halt frac ball 501. In this
state, fracturing port
102 will be open, allowing flow of proppant from chamber 104 through
fracturing port 102 and
into a formation, thereby allowing fracturing to take place.
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[00331 Figure 6 illustrates an impedance device in between fracturing port. An
impedance
device can counteract actuator 206, in an embodiment where actuator 206 is a
biasing device,
such as a spring. In one embodiment, an erosion device, in the form of a
string 601, can be an
impedance device. String 601 can connect sliding sleeve 200 with base pipe
100. While intact,
string 601can prevent actuator 206 from releasing. Once the string 601 is
broken, actuator 206
can push sliding sleeve 200. One method of breaking string 601 can be by
pushing a corrosive
material reactive with string through fracturing port, as corrosive material
can deteriorate string
601 until actuator 206 can overcome its impedance.
[0034] Figure 7 illustrates fracturing valve 500 in production mode. As
sliding sleeve 200 is
pushed towards outer ring 207 by actuator 206, fracturing port 102 can close
and production port
103 can open. Concurrently, frac ball 501 can push stop balls 502 back into
the inner end of first
sleeve 202, which can further allow frac ball 501 to slide through base pipe
101 to another
fracturing valve 500. Once production port 103 is opened, extraction of oil
and gas can start. In
one embodiment, production ports 103 can have a check valve to allow
fracturing to continue
downstream without pushing frac fluid through the production port 103.
[0035] Various changes in the details of the illustrated operational methods
are possible without
departing from the scope of the following claims. Some embodiments may combine
the
activities described herein as being separate steps. Similarly, one or more of
the described steps
may be omitted, depending upon the specific operational environment the method
is being
implemented in. It is to be understood that the above description is intended
to be illustrative,
and not restrictive. For example, the above-described embodiments may be used
in combination
with each other. Many other embodiments will be apparent to those of skill in
the art upon
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reviewing the above description. The scope of the invention should, therefore,
be determined
with reference to the appended claims, along with the full scope of
equivalents to which such
claims are entitled. In the appended claims, the terms "including" and "in
which" are used as the
plain-English equivalents of the respective terms "comprising" and "wherein."
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