Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR PERFORATING AND FRACTURING
IN A WELL
BACKGROUND
[0001] In preparing wells for production of formation bearing fluids, a well
often
is subjected to perforating and fracturing processes. Conventionally,
perforating has been
accomplished with a stand-alone wireline crew utilizing a dedicated wireline
unit, a
pickup and personnel specifically trained to operate the wireline unit and
conduct the
perforation procedures. A separate stand-alone fracturing crew has been used
to carry out
the pumping or fracturing portion of the overall process. The fracturing crew
similarly
utilizes a crane and its own dedicated vehicles, equipment and personnel
trained to carry
out the fracturing procedures.
[0002] The use of separate crews, separate vehicles and separate equipment for
processes that are often conducted simultaneously can lead to inefficiencies.
For
example, the procedural separation of perforating and fracturing can require
extra
vehicles and extra personnel. This, in turn, creates increased costs,
increased time
requirements, and increased logistical difficulty, particularly when
alternating perforating
and fracturing procedures are conducted in a given well. Additionally, the
relatively
large number of vehicles and personnel requires a relatively large location
footprint at a
given well site.
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SUMMARY
[0003] In general, the present invention provides a system and method for
creating greater efficiency during perforating and fracturing procedures in a
well. The
system and method utilize a vehicle having a crane for lowering and raising
fracturing
and perforating equipment in a wellbore. Additionally, a wireline winch is
mounted
directly to the crane to facilitate the run in of conductive wireline for
perforating
procedures. This combination greatly facilitates sequential perforating and
fracturing
procedures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Certain embodiments of the invention will hereafter be described with
reference to the accompanying drawings, wherein like reference numerals denote
like
elements, and:
[0005] Figure 1 is a schematic side view of a well site with an example of a
crane
and a control vehicle, according to an embodiment of the present invention;
[0006] Figure 2 is a side view of an example of a crane base with combined
wireline winch, according to an embodiment of the present invention;
[0007] Figure 3 is a side view of an example of a crane truck with crane in an
operational position, according to an embodiment of the present invention;
[0008] Figure 4 is a side view of the crane truck illustrated in Figure 3 with
crane
in a transport position, according to an embodiment of the present invention;
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[0009] Figure 5 is a schematic view of an example of a control system used to
control and monitor aspects of perforation and fracturing procedures,
according to an
embodiment of the present invention;
[00010] Figure 6 is an illustration of a well with several zones in which
perforation
and fracturing procedures have been conducted, according to an embodiment of
the
present invention; and
[0011] Figure 7 is a procedural flowchart illustrating an example of a
perforating/fracturing procedure, according to an embodiment of the present
invention.
DETAILED DESCRIPTION
[0012] In the following description, numerous details are set forth to provide
an
understanding of the present invention. However, it will be understood by
those of
ordinary skill in the art that the present invention may be practiced without
these details
and that numerous variations or modifications from the described embodiments
may be
possible.
[0013] The present invention generally relates to well preparation procedures.
In
preparing or constructing certain wells, perforation and fracturing procedures
often are
used to facilitate the production of desired fluids, e.g. oil, from the
subterranean
formation. The present invention generally combines aspects of the perforation
and
fracturing techniques to increase the efficiency with which these procedures
are carried
out at a given well site.
[0014] Efficiency is enhanced, at least in part, by combining a wireline winch
system with a crane used in fracturing. In at least some embodiments, the
wireline winch
control/acquisition systems also can be combined with the fracturing control
and
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monitoring systems. This combination eliminates the previous need for separate
wireline
vehicles and also reduces the number of personnel required by integrating
perforating
skills and personnel with the fracturing crew. In some applications, this
enables the
reduction of personnel by at least two individuals.
[0015] Referring generally to Figure 1, a well site 20 is illustrated as
having a
well comprising a wellbore 24 drilled into a formation 26. Wellbore 24 extends
downwardly from a wellhead 28 positioned at a surface 30 of the earth.
Wellbore 24
provides access for equipment used in perforating and fracturing procedures
designed to
enhance production of desired fluids from formation 26. As illustrated,
aspects of the
perforating and fracturing processes are combined to provide greater
efficiency with
respective the well preparation project.
[0016] For example, a combined perforating and fracturing unit 32 is utilized
to
deploy and remove perforating and fracturing equipment 34 to and from wellbore
24. In
this embodiment, combined unit 32 comprises a crane 36 and a wireline winch 38
mounted directly to crane 36. Combined unit 32 also may comprise a vehicle,
such as a
crane truck 40, for transporting the combined crane and wireline winch. In
this
embodiment, crane truck 40 is a road legal vehicle that enables the transport
of crane 36
and wireline winch 3 8 from one well site to another.
[0017] In the example illustrated, equipment 34 comprises fracturing equipment
42 and perforating equipment 44, such as a perforating gun 46. Crane 36 is
used to move
equipment 34 to desired locations within wellbore 24 via, for example, a cable
48.
Wireline winch 38 is used to supply a conductive wireline 50 into wellbore 24
to enable
the passage of signals to perforating gun 46 for initiation of perforation at
desired
locations within the wellbore. The conductive wireline also can be used for
other
purposes, such as providing a path for signal flow during data acquisition.
Accordingly,
a single vehicle can be utilized for both perforating and fracturing support
in a combined
process as opposed to using separate vehicles, separate crews and distinct
procedures.
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[0018] According to other aspects of the embodiment illustrated in Figure 1, a
control system 52 can be used to control and monitor aspects of both the
perforating and
fracturing processes. For example, control system 52 may comprise controls 54
dedicated to control of wireline winch 38 as well as the wireline computer
control/acquisition system. Additionally, control system 52 may comprise frac
controls
56, such as those used to control/monitor the various aspects of a fracturing
procedure.
Control system 52 also can be used to control crane 36. In the embodiment
illustrated,
the overall control system 52 is located in a vehicle 58 which may be deployed
at the well
site 20. By way of example, vehicle 58 may comprise a "frac van" in which the
fracturing control system has been combined with a control system for wireline
winch 38,
wireline 50 and any data acquisition equipment providing signals through
wireline 50.
[0019] As illustrated, a communication line 60 extends between crane truck 40
and vehicle 58. The communication line 60 may comprise a cable or other
hardwired
communication line directly coupling control system 52 with wireline winch,
crane 36
and equipment 34. However, communication line 60 may utilize other types of
communication, including wireless communication. Alternately, signals may be
sent
between control system 52 and crane truck 40 over additional communication
lines or
networks. In this latter embodiment, control system 52 could be utilized to
control/monitor the fracturing and perforating processes from a location
separated from
well site 20.
[0020] Referring generally to Figure 2, an embodiment of combined unit 32 is
illustrated in enlarged form. As illustrated, wireline winch 38 is affixed to
crane 36 at an
attachment 62. Attachment 62 may comprise weldments, fasteners, e.g. bolts, or
other
mechanisms for securely affixing wireline winch 38 to crane 36. Thus, wireline
winch 38
and crane 36 can be rotated together about an axis of rotation 64. In most
applications,
axis 64 will be oriented generally perpendicular to a surface on which crane
truck 40 is
parked.
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[0021] In this embodiment, crane 36 comprises a rotatable base 66 which is
rotatable by, for example, hydraulic input as with conventional crane units. A
platform
68 and a crane torrent 70 are mounted above base 66. As illustrated, wireline
winch 38 is
affixed to torrent 70 and is rotatable with torrent 70, platform 68 and base
66 about axis
64. Crane 36 further comprises a boom 72 pivotably mounted to torrent 70 by a
pivot
junction 74. An actuator 76, such as a hydraulic cylinder, is used to pivot
boom 72.
Additionally, crane 36 comprises a reel 78 about which cable 48 is wound. Reel
78 is
mounted on an arm 80 that extends from torrent 70, and the reel is rotated by
a powered
device 82. One example of a suitable device 82 is a hydraulic motor supplied
with
hydraulic fluid through flow lines 84. The hydraulic motor 82 can be powered
to spool
up cable 48 or to release additional cable 48 as desired for appropriate
movement of
equipment 34 within wellbore 24.
[0022] Wireline winch 38 comprises a framework 86 that is mounted to crane 36.
For example, framework 86 can be affixed via attachment 62 to crane torrent 70
such that
framework 86 extends from axis 64 in generally the same direction as arm 80.
Wireline
winch 38 further comprises a wireline reel 88 rotatably mounted on framework
86.
Wireline reel 88 is driven by a powered device 90, such as an electric motor
or a
hydraulic motor. Accordingly, conductive wireline 50 can be spooled up or
released by
controlling the rotation of wireline reel 88 via powered device 90. Wireline
winch 38
further comprises a guide boom 92 pivotably mounted to framework 86 via a
mounting
portion 94. The guide boom 92 can be pivoted by an actuator 96, such as a
hydraulic
cylinder. Hydraulic fluid may be supplied to hydraulic cylinder 96 and device
90, for
example, via hydraulic lines 98. Additionally, a wireline guide 100 is
disposed on boom
92 to guide conductive wireline 50 as wireline reel 88 is rotated during
perforation/acquisition procedures.
[0023] In an embodiment that utilizes hydraulically activated components, such
as hydraulic actuators 76 and 96, hydraulically driven reels 78 and 88, and a
hydraulically
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rotated crane, pressurized hydraulic fluid may be supplied via a hydraulic
control system
102, such as those commonly used in a variety of equipment applications. The
hydraulic
control system 102 may have separate sections 104 dedicated to controlling
different
applications, e.g. wireline winch components or crane components.
Additionally, the
hydraulic control system 102 may be controlled remotely via overall control
system 52.
[0024] An embodiment of crane truck 40 is illustrated in Figure 3. In this
embodiment, crane truck 40 is a road legal truck having a chassis 106
supported on front
wheels 108 and rear wheels 110. As illustrated, rear wheels 110 are mounted on
a pair of
axles. However, crane truck 40 may comprise a single rear axle or multiple
rear axles
depending on the weight of the equipment carried as well as the regional
regulations
pertaining to use of vehicles on public roadways.
[0025] A cab 112 is mounted on chassis 106, and combined unit 32 is mounted to
chassis 106 rearwardly of cab 112. Combined unit 32 may be mounted to chassis
106 via
a platform 114 that is supported by chassis 106. In this embodiment, combined
unit 32 is
mounted toward the rear of platform 114 to create a load region 116 between
cab 112 and
combined unit 32 for carrying materials, equipment or other items related to
the
perforation and/or fracturing procedures.
[0026] In the embodiment of Figure 3, crane truck 40 is illustrated in an
operational state. Accordingly, crane 36 and wireline winch 38 have been
rotated to the
rear of crane truck 40 and are in a raised condition. In fact, boom 72
comprises at least
one extensible section 118 that is extended to a degree that enables cable 48
and wireline
50 to extend downwardly into well 22. Cable 48 extends from reel 78 to a
distal end 120
of extended section 118 and over a pulley or pulleys 122. Similarly, wireline
50 extends
from wireline winch 38 and over a wireline pulley system 124 suspended from
distal end
120. It should be noted that outriggers (not shown) or other mechanisms can be
used to
stabilize crane truck 40 during operation of crane 36.
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[0027] Upon completion of the perforating and fracturing procedures at well
site
20, crane truck 40 can be reconfigured to a transport state, as illustrated in
Figure 4. In
other words, cable 48 and wireline 50 are reeled in, and extended section 118
is retracted.
Additionally, crane 36 and wireline winch 38 are rotated together about axis
64, and
boom 72 as well as guide boom 92 are lowered for transport to the next well
site in the
next perforation/fracturing project. Additionally, materials, equipment, etc.
can be placed
on platform 114 in load region 116 for transport.
[0028] Another unique aspect of combined unit 32 is that the perforation and
fracturing procedures can be controlled with the single control system 52, as
further
illustrated in Figure 5. By way of example, control system 52 may be enclosed
in vehicle
58 for easy transport from one well site to another. At each well site, the
control system
52 is coupled to combined unit 32 via, for example, communication lines 60 to
enable the
flow of signals between the operational unit, i.e. combined unit 32, and the
remote,
mobile control system.
[0029] As illustrated, control system 52 may be a computer based control
system
having a processor or processors 124 for managing the input and output of
data.
Additionally, control system 52 may comprise a display 126 for displaying to
an operator
a variety of information related to operation of the crane, wireline winch and
the
acquisition of well related data.
[0030] By way of example, system 52 may be coupled to a variety of
components, such as components 128 and 130 for monitoring operational aspects
of the
crane 36 and/or the wireline winch 38. In this example, component 128 is a
camera, such
as a digital video camera, that is mounted on or in proximity to the crane 36
and/or
wireline winch 38. Video camera 128 enables, for example, an operator to
monitor the
spooling of cable 48 or wireline 50 during perforation and fracturing
procedures.
Component 130 can comprise another video camera or another type of sensor or
other
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component that enables an operator to monitor operational aspects of crane 36
and/or
wireline winch 38.
[0031] Control system 52 also may be used to directly control the operation of
crane 36 and wireline winch 38. For example, control system 52 may be coupled
to
hydraulic control system 102 and to each of the control components 104 that
govern the
hydraulic inputs to wireline winch 38 and to crane 36. This enables a remote
operator
within vehicle 58 to control operation of combined unit 32 by, for example,
raising and
lowering boom 72 and guide boom 92, controlling the speed and direction of
reel 78 and
reel 88, and controlling the rotation of crane 36 and wireline winch 38 about
axis 64.
[0032] Additionally, control system 52 may be coupled to equipment 34 via
conductive wireline 50. This enables an operator to output command signals,
for
example, to perforating gun 46 to initiate perforation. It also enables the
operator to
monitor various well related parameters, provided equipment 34 includes
appropriate
sensors or other instruments able to output data to control system 52 via
wireline 50.
Accordingly, an operator potentially has great ability to monitor and control
many
aspects of both the perforation procedures and fracturing procedures from a
single,
remote location. Furthermore, the mobile vehicle 58 enables movement of the
control
system from one well site to another.
[0033] In many applications, such as staged fracturing projects, combined unit
32
enhances the efficiency with which the perforation procedures and fracturing
procedures
can be carried out in multiple formation zones, e.g. formation zones 134, 136
and 138, as
illustrated in Figure 6. Perforations 140 can be formed in each of the
plurality of
formation zones, and fracturing processes can be conducted upon the completion
of
perforations in each zone. This allows different zones to be fractured
differently due to,
for example, variations in permeability from one zone to another. In any
event, the
procedures can be carried out with the crane 36 and the wireline winch 38
combined on a
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single vehicle with a single crew as opposed to organizing the cooperative
efforts of
separate vehicles with separate crews.
[0034] One example of the operation of combined crane 36 and wireline winch 38
can be described with reference to Figure 7. Initially, equipment 34 is run
into wellbore
24 via crane 36, as illustrated by block 142. The equipment 34 is moved by
cable 48 of
crane 36, and simultaneously conductive wireline 50 also may be run into
wellbore 24.
When the equipment is at a desired location within wellbore 24, e.g. formation
region
134, that zone of the wellbore is perforated by sending a signal through
conductive
wireline 50 to perforating gun 46, as illustrated by block 144. Upon
perforation, the
formation region is fractured, as illustrated by block 146.
[0035] When the initial fracturing procedure is completed, the equipment is
lifted
to the the next wellbore/formation zone, e.g. zone 136, and wireline 50 is
reeled in to
remove slack, as illustrated by block 148. The perforation procedure is then
conducted in
this zone, as illustrated by block 150. Following perforation, the fracturing
procedures
can be conducted in this formation region, as illustrated by block 152. This
process can
be repeated for additional zones until all of the desired wellbore zones are
perforated and
fractured. After the final fracture procedure, the equipment is lifted from
wellbore 24, as
illustrated by block 154. Crane 36 and wireline winch 38 can then be placed
into a
configuration for transport, and crane truck 40 can be used to move the
equipment to the
next well site.
[0036] It should be noted that crane truck 40 and control system vehicle 58
may
be constructed in a variety of configurations. Additionally, the equipment
used for the
perforation and fracturing procedures can vary according to specific project
objectives,
equipment available, environment and other factors. Also, the size and
configuration of
the crane and the wireline winch can vary based on the specific types of
projects for
which the combined unit is utilized.
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[0037] Accordingly, although only a few embodiments of the present invention
have been described in detail above, those of ordinary skill in the art will
readily
appreciate that many modifications are possible without materially departing
from the
teachings of this invention. Accordingly, such modifications are intended to
be included
within the scope of this invention as defined in the claims.
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