Whipstock liner

TECHNICAL FIELD

The present invention relates to well bore patterns, and more particularly to forming one or more lateral well bores off a first drilled well bore.

BACKGROUND

In some wells, a liner can be used to prevent the wall of a well bore from caving or to filter solids (particulate or larger) from entering the well bore. Liners can also be run to isolate one or more subterranean zones, for example, to protect fresh-water formations, isolate a zone of lost returns or isolate formations with significantly different pressure gradients. Liners are usually manufactured from plain carbon steel, but may be specially fabricated of stainless steel, aluminum, titanium, fiberglass and other materials.

In some cases, it is desirable to drill a second well bore from a first well bore, i.e., a lateral. One manner of drilling the second well bore involves a whipstock. Whipstocks include an inclined wedge placed in a well bore that forces the drill bit to start drilling in a direction away from the well bore axis. The whipstock has a hard surface so that the bit will preferentially drill through either casing or rock rather than the whipstock itself. Whipstocks may be oriented in a particular direction if needed, or placed into a well bore blind, with no regard to the direction they face. Most whipstocks are set on the bottom of the hole or on top of a high-strength cement plug or a whipstock anchor packer (e.g., a special-purpose packer placed in the casing to permit a sidetrack operation), but some are set in an open well bore. When the operations involving the whipstock are complete, the whipstock is often retrieved from the well bore.

SUMMARY

The present invention relates to well bore patterns, and more particularly to forming one or more lateral well bores off a first drilled well bore.

In one aspect, a device includes a liner having a setting collar at one end, the setting collar adapted to couple with a liner running tool, the setting collar further adapted to attach a liner tubing; and a whipstock surface on the setting collar adapted to deflect a drilling string.

In another aspect, a liner system includes: a first length of liner tubing extending from a first end to a second end; and a setting collar adapted to couple with a liner running tool, the setting collar including a whipstock surface adapted to deflect a drilling string. The setting collar is coupled to the first end of the first length of liner tubing.

In another aspect, a method of forming a well system includes: forming a first well bore; installing a first liner in the first well bore, the first liner having a first whipstock surface adapted to deflect a drilling string; and then forming a second well bore extending from the first well bore by deflecting a drilling string through contact with the first whipstock surface.

Embodiments can include one or more of the following features.

In some embodiments, the liner includes a length of liner tubing. In some instances, a threaded connection couples the setting collar to the length of liner tubing. In some instances, a first inner diameter of the setting collar at least as large as a second inner diameter of the liner tubing. In some instances, the liner tubing is selected from the group consisting of solid liner tubing, apertured liner tubing, and other types of liner tubing.

In some embodiments, the whipstock surface is at least partially defined by additional material coupled to the end of the setting collar.

In some embodiments, the whipstock surface is defined at an end of the setting collar and is formed at a an angle to a longitudinal axis of the setting collar. In some instances, the angle is between 2 and 45 degrees (e.g., about 3 degrees, between 10 and 20 degrees, and/or about 15 degrees).

In some embodiments, the whipstock surface is defined by an end portion of setting collar sidewalls. In some instances, the end portion of the setting collar sidewalls has a first sidewall thickness than is greater than a second sidewall thickness of a second portion of the setting collar sidewalls. In some instances, the first sidewall thickness is greater than a third sidewall thickness of a length of liner tubing coupled to the setting collar. A threaded connection can couple the setting collar to the first length of liner tubing. A first inner diameter of the setting collar can be at least as large as a second inner diameter of the liner tubing.

In some embodiments, liner systems also include a second length of liner tubing, the second length of liner tubing attached to the second end of the first length of liner tubing.

In some embodiments, the first liner includes a first setting collar (e.g., a setting collar is adapted to couple with a liner running tool) attached to a length of liner tubing. In some instances, installing a liner includes orienting the first whipstock surface by rotating the first setting collar. Rotating the first setting collar can include engaging the first setting collar with torque fins on the liner running tool.

In some embodiments, methods also include installing a second liner in the second well bore, the second liner having a second whipstock surface on the second setting collar adapted to deflect a drilling string. In some instances, methods also include forming a third well bore by deflecting a drilling string through contact with the second whipstock surface. The third well bore can extend from the first well bore

An advantage of one or more implementations is that the whipstock surface is integrated with the setting collar of the liner. Thus, a separate whipstock need not be provided. As the whipstock surface resides at the end of a liner, the spacing between laterals is not limited by the size of a separate whipstock tool. In other words, multiple whipstock surfaces can be positioned closer to one another in a well bore than multiple separate whipstocks, because the whipstock surfaces residing at the end of a liner take up less space. As a result, multiple lateral well bores can be diverted from the original at more closely spaced intervals. For example, one liner can be positioned adjacent, and in some instances within a few inches of or in contact with, the whipstock surface of another liner. This allows the first liner to communicate flow into the second string and reduces the chance of the well bore plugging if it collapses. In some implementations, the whipstock surface maintains its position and orientation within the well bore by reacting against the liner tubing which may be frictionally held in the well bore. In some implementations, there are no moving parts associated with a gripping mechanism to fail. Also, because of the lack of moving parts, the system is inexpensive to construct.

Another advantage of one or more implementations is increased drilling efficiency because of a reduced number of trips into and out of the well bore. For example, a well system with single lateral well bore diverging from a horizontal well bore can be formed with only three trips into and out of the well system using the devices, systems, and methods described above. First, a drill string can be used to form the horizontal well bore extending from an articulated well bore. Second, after the drill string is withdrawn, a working string can be used to install a liner with a setting collar with a whipstock surface in the horizontal well bore. The liner is positioned such that the setting collar is disposed at the point the lateral well bore will be formed. Third, after the working string is withdrawn, the drill string travels back through the articulated well bore and horizontal well bore until it is deflected by the whipstock surface on the setting collar of the liner in the horizontal well bore. After forming the lateral well bore, the drill string is withdrawn. In contrast, use of a separate whipstock requires additional trips into and out of the well bore by the working string to place and retrieve the whipstock (e.g., after the liner is installed in the horizontal well bore and after the lateral well bore is formed).

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic partial side cross-sectional view of an illustrative liner system constructed in accordance with the concepts described herein.

FIG. 2 is a schematic side cross-sectional view of an illustrative well system constructed in accordance with the concepts described herein.

FIG. 3 is a schematic plan view of the illustrative well system of FIG. 1.

FIG. 4 is a schematic side cross-sectional view of the illustrative well system of FIG. 2 during its construction in accordance with the concepts described herein.

FIG. 5 is a schematic side cross-sectional view of the illustrative well system of FIG. 2 during its construction in accordance with the concepts described herein.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring to FIG. 1, an illustrative liner system 10 constructed in accordance with the concepts described herein is depicted depending from a liner running tool 12 in a well bore 14. The illustrative liner system 10 includes a tubular setting collar 16 coupled to one or more lengths of liner tubing 18. In one instance, the tubular setting collar 16 is coupled to an adjacent length of liner tubing 18 with a threaded connection. The liner tubing 18 can be one or more lengths of solid tubing, apertured tubing, and other types of liner tubing.

Although there are numerous liner running tools that can be used in accordance with the concepts described herein, an illustrative liner running tool 12 is depicted in FIG. 1. The illustrative liner running tool 12 includes a body portion 28 that is adapted to couple to (and depend from) a working string 26. The body portion 28 is at least partially received within the interior of the setting collar 16. One or more radially extendable/retractable dogs 20 are positioned about the body portion 28. In the extended position, the dogs 20 protrude from the exterior of the body portion 28. FIG. 1 depicts the dogs 20 extended into a corresponding groove 22 in the interior of the setting collar 16. The dogs 20 abut a downwardly facing shoulder 24 of the groove 22 and support the weight of liner system 10. When retracted, the dogs 20 reside out of the groove 22. In one instance, the dogs 20 are biased to the radially extended position, and can be retracted by application of hydraulic pressure through the interior of the liner running tool 12. Thus, to release the dogs 20 from the groove 22 and the liner running tool 12 from the setting collar 16, hydraulic pressure is applied through the interior of liner running tool 12. In other instances, the dogs 20 may be extended or retracted by one or more of mechanical manipulation via the working string 26, hydraulic pressure, electric power or other mechanism. When the dogs 20 are released from the groove 22, the liner running tool 12 can be withdrawn from the setting collar 16.

The liner running tool 12 further includes one or more extendable/retractable torque fins 28 positioned about the body portion 28. In the extended position, the torque fins 28 protrude from the exterior of the body portion 28. FIG. 1 depicts a torque fin 28 extended into a corresponding longitudinally (with respect to the setting collar 16) oriented slot 30 in the interior of the setting collar 16. The number of slots 30 can correspond to the number of torque fins 28. When the liner running tool 12 is rotated relative to the setting collar 16, the torque fin 28 abuts one or the other sidewall 32 of the slot 30, and cause the setting collar 16 to rotate with the liner running tool 12. When retracted, the torque fins 28 reside out of the slots 30, and the liner running tool 12 can rotate in the setting collar 16. In one instance, the torque fins 28 are spring biased to the radially extended position, and include a sloped upper surface 34. As the liner running tool 12 is drawn upward in the setting collar 16, the sloped upper surface 34 bears against the upper wall 36 of the slot 30 and wedges the torque fins 28 to the retracted position and out of the slots 30. Thereafter the running tool 12 may be withdrawn from the setting collar 16. In other instances, the torque fins 28 may be extended or retracted by one or more of mechanical manipulation via the working string 26, hydraulic pressure, electric power or other mechanism.

The tubular setting collar 16 has a whipstock surface 40 on its upper end. As is discussed in more detail below, the whipstock surface 40 operates to deflect drilling operations to deviate from a longitudinal axis of the setting collar 16. The longitudinal axis of the setting collar 16 is substantially parallel or coincides with the longitudinal axis of a portion of the well bore (e.g. well bore 14) in which the setting collar 16 resides. The whipstock surface 40 is defined at the end of the setting collar 16 and formed at a specified angle θ to the longitudinal axis of the setting collar 16. The specified angle θ is selected based on the desired angle of departure of the drilling operations from the longitudinal axis of the well bore. In some instances, at least a portion of the whipstock surface is at an acute angle to a longitudinal axis of the setting collar. For example, in one instance, the whipstock surface 40 is formed at a 15° angle to the longitudinal axis of the well bore 14. In other instances, the whipstock surface 40 can be formed at shallower or steeper angles. For example, in another instance, the whipstock surface 40 is formed at a 3° angle to the longitudinal axis of the well bore 14. In certain implementations, the whipstock surface 40 has two or more angles. For example, in one instance, the whipstock surface 40 has an initial angle of 15° and subsequently an angle of 3° to the longitudinal axis of the well bore 14.

In certain implementations, the whipstock surface 40 is defined by the end walls 42 of the setting collar 16. Accordingly, the whipstock is integral to the liner tubing 18 in contrast to a conventional whipstock that is coupled to an interior of a liner or casing. To this end, the setting collar 16 may have an increased sidewall thickness 44 about the end walls 42. In some instances, this sidewall thickness 44 is greater than the sidewall thickness 46 of the liner tubing 18. In one instance, the setting collar 16 has an outer diameter approximately equal to the outer diameter of a stock sized collar for use with the size of liner tubing 18 used, but has an inside diameter sized to receive a stock size liner running tool 12 for running a smaller size of liner tubing. For example, for a system with 4.5 inch (114.3 mm) nominal outer diameter liner tubing 18, the setting collar 16 can have 5.0 inch (127 mm) nominal outer diameter (i.e. approximately equal to the standard size casing collar), but have an inner diameter sized to accept a stock liner running tool 12 configured for running a 3.5 inch (88.9 mm) nominal outer diameter liner tubing 18. In other implementations, additional material may be coupled to the end of the setting collar 16 to define a whipstock surface 40. The inner diameter of the setting collar 16 is equal to or greater than the inner diameter of the liner tubing 18. For example, in some instances, a smallest inner diameter of the setting collar is at least as large as a smallest inner diameter of the liner tubing.

In certain implementations, the whipstock surface 40 can be harder than the remainder of the setting collar 16. In one instance, the whipstock surface 40 is steel that has been surface hardened. In other instances, a hardened surface is deposited on the whipstock surface 40 in addition to, or as an alternative to, the surface hardening.

In some embodiments, the setting collar 16 and whipstock surface 40 are of one-piece construction (e.g., the whipstock surface is formed directly on the setting collar). In some embodiments, the setting collar 16 and whipstock surface 40 are of unitary multi-piece construction (e.g., the whipstock surface can be formed on a separate work piece that fixedly attached to the setting collar so that the setting collar and whipstock-bearing work piece are not separable downhole.

The liner running tool 12 enables the illustrative liner system 10 to be placed in a well bore, such as well bore 14. To this end, the liner running tool 12 is coupled to a working string 26 and received in the setting collar 16 of the illustrative liner system 10. The dogs 20 are changed to the extended position to be received in the groove 22 of the setting collar 16. If biased to the extended position, the dogs 20 automatically snap into the groove 22. The liner system 10 is thereafter supported from the liner running tool 12, as the dogs 20 bear against the shoulder 24 of groove 22. Additionally, the torque fins 28 of the liner running tool 12 can be aligned with the slots 30 in the setting collar 16. When changed to the extended position, the torque fins 28 are received in the slots 30 and torsionally lock the liner running tool 12 to the setting collar 16 (and thus illustrative liner system 10) to rotate together. If biased to the extended position, the torque fins 28 automatically snap into the slots 30 when aligned with the slots 30. Thereafter, the illustrative liner system 10 depends from the liner running tool 12, and is run into a well bore, such as well bore 14 as is depicted in FIG. 4, on the working string 26. Once in the desired location within the well bore and/or as the illustrative liner system is moved into location in the well bore, the illustrative liner system 10 can be rotationally oriented to align the whipstock surface 40 to deflect drilling operations in the desired orientation by rotating the liner running tool 12 via the working string 26. The liner running tool 12 can then be released from the illustrative liner system 10 by actuating the dogs 20 to the retracted position (for example, by applying hydraulic pressure through the working string 26 into the interior of the liner running tool 12), actuating the torque fins 28 to the retracted position (for example, by wedging sloped upper surface 34 against the upper wall of the slot 36), and withdrawing the liner running tool 12 from the setting collar 16. The setting collar 16 and whipstock surface 40 need not be attached (for example, by slips) to the wall of the well bore, because they are affixed to the liner tubing 18. The liner tubing 18, in turn, is frictionally held in the well bore 14. However, in some instances, the setting collar can include a liner hanger and/or can include a gripping assembly (e.g., slips). The gripping assembly is actuable into gripping engagement with a wall of the well bore to anchor the setting collar, and liner tubing, in the well bore.

FIG. 2 depicts an illustrative well system 100 constructed in accordance with the concepts described herein. The well system 100 includes a surface well bore 110 and one or more secondary well bores 112 (three shown) formed near to, and in some instances adjacent to, one another. The secondary well bores 112 define a well bore pattern. The surface well bore 110 extends either directly from the surface 116, or extends from another bore, pit, shaft, fissure, cavity, or other feature (not specifically shown) in communication with the surface 116. In FIG. 2, the surface well bore 110 is depicted as an articulated well bore having a first portion 118, a second portion 120, and a curved portion 122 connecting the first portion 118 and the second portion 120. The second portion 120 extends into a subterranean zone 114. Although depicted as being substantially vertical, some or all of the first portion 118 may be slanted, undulating, or otherwise not vertical. Likewise, although depicted as being substantially horizontal, some or all of the second portion 120 may be slanted, undulating, or otherwise not horizontal. A casing 124 or other type of liner tubing may optionally be provided through at least a portion of the surface well bore 110. The casing 124 may be provided, for example, to prevent collapse of the earth about the well bore 110 and/or to isolate other subterranean zones through which the well bore 110 may pass from communicating with the well bore 110. FIG. 3 depicts the casing 124 extending from a wellhead 136 about the surface 116 downward through the first portion 118, curved portion 122 and into the second portion 120. In other instances, the casing 124 can extend solely in the first portion 118 or through the first portion 118 and into the curved portion 122.

In one instance, the subterranean zone 114 is a coal seam. However, the concepts described herein are applicable to other types of subterranean zones. For example, the subterranean zone 114 can be an oil and gas formation, water producing formation, or other type of formation.

The illustrative well system 100 further includes a cavity 126 (an enlarged cavity is shown) formed in or near to the subterranean zone 114. Other well systems formed according to the concepts described herein can omit the cavity 126. In one instance, the cavity 126 is formed through a surface communicating cavity well bore 128 extending either directly from the surface 116, or from another bore, pit, shaft, fissure, cavity, or other feature (not specifically shown) in communication with the surface 116. Therefore, the cavity 126 corresponds to the location of an intersection between the surface well bore 110 and the cavity well bore 128. The cavity 126 may have a larger transverse dimension than the cavity well bore 128, as is shown in FIG. 2, or may have a transverse dimension that is smaller than or substantially equal to the transverse dimension of the cavity well bore 128. Some or all of the cavity well bore 128 may be provided with a casing 130 or other type of liner tubing. The casing 130 may be provided, for example, to prevent collapse of the earth about the well bore 128 and/or to isolate other subterranean zones through which the well bore 128 may pass from communicating with the well bore 128. In FIG. 2, the casing 130 is shown extending from a wellhead 132 at the surface 116 to the cavity 126. The casing 130 may also be omitted. The cavity 126 can also optionally be provided with a sump 134 that extends downward beneath the cavity 126. In operation of the illustrative well system 100, the sump 134 functions to collect fluids and fines received in the cavity 126 to facilitate removal of the fluids (and sometimes also the fines) to the surface 116. The inlet 144 of a pump 146 can be provided in the sump 134 to pump the fluids from the sump 134 to the surface 116. Alternately, the inlet 144 of the pump 146 can be provided within the cavity 126 or within the interior of the cavity well 128 to pump fluids from the cavity 126 to the surface 116. An apertured liner section 152 may be provided in the cavity 126 and communication with the interior of the cavity well bore 128. The cavity 126 may be filled with gravel or other particulate 148 (i.e. gravel packed) to help support the cavity 126 from collapse and to filter against passage of pieces of the subterranean zone 114 to the surface 116.

The secondary well bores 112 are depicted as extending substantially horizontal within the subterranean zone 114 that likewise extends substantially horizontal. The secondary well bores 112 need not be horizontal, and in other instances, one or more of the secondary well bores 112, or portions thereof, may be vertical, slanted, undulating, or otherwise not horizontal. In one instance, one or more of the secondary well bores 112 is slanted to follow the updip or the downdip of the subterranean zone 114. One or more of the secondary well bores 112 may, alternately or additionally, have a shallow slope that causes fluids received in the secondary well bores 112 to flow towards the cavity 126.

FIG. 2 depicts the secondary well bores 112 originating from the same location about the end of the second portion 120 of the surface well bore 110. In other instances, one or more of the secondary well bores 112 can originate from distinct locations within or apart from the surface well bore 110 or subterranean zone 114. The secondary well bores 112, or portions thereof, may be substantially parallel to other of the secondary well bores 112 or may diverge from other of the secondary well bores 112. In FIG. 2, the secondary well bores 112 are depicted as diverging from one another near their origin and being substantially parallel to one another in a portion that intersects the cavity 126. As is seen in FIG. 3, the secondary well bores 112 thereafter diverge and extend to a boundary of a specified access area 142 to more evenly access, for example to drain, the specified access area 142. All of the secondary well bores 112 may be substantially aligned in the same horizontal, vertical or other plane, or one or more of the secondary well bores 112 may reside at least partially out of plane with others of the secondary well bores 112.

It should be appreciated that the systems and methods of using the illustrative liner system 10 described herein are described with respect to the specific configuration of the illustrative well system 100 for convenience of discussion only. The systems and methods described herein can be applied equally to other configurations of well systems and well bores. For example, other well systems may omit the cavity well bore, have different patterns of secondary well bores, or have other different configurations.

One or more of the secondary well bores 112 is provided with an illustrative liner system 10 that extends through at least a portion thereof. The liner systems 10 may be provided, for example, to prevent the subterranean zone 114 from collapsing into the secondary well bores 112. FIG. 2 depicts a liner system 10 provided in two of the completed secondary well bores 112, and a liner 138 optionally excluding the whipstock surface 40 installed the last installed liner system 10. The liner systems 10 and liner 138 extend from about the second portion 120 of the surface well bore 110 and through the cavity 126 continuing on into the subterranean zone 114. The liner systems 10 and/or liner 138 may further extend to the end of each of the secondary well bores 112. One or more of the liners 10, 138 and/or liner tubings 18 may be provided with apertures 140 to allow passage of fluid between their respective exterior and interior. The liners 10, 138 and/or liner tubings 18 may, in some instances, be jointed lengths of tubing connected by collars 150. In other instances, the liners 10, 138 and/or liner tubings 18 may be continuous tubing. The liners 10, 138 and/or liner tubings 18 may be affixed or otherwise intended to reside in the secondary well bores 112 for the life or a majority of the life of the well system 100.

Turning now to FIG. 4, an illustrative method for forming well bores is described with reference to the construction of illustrative well system 100. In construction of the illustrative well system 100, the cavity well bore 128 is drilled from the surface 116 to the desired location of the cavity 126 in or near the subterranean zone 114. If a sump 134 is to be provided, the cavity well bore 128 may be drilled to extend below the desired location of the cavity 126. In some instances, a casing 130 can be positioned (and optionally cemented in place) in the cavity well bore 128 above the location of the cavity 126. The cavity 126 is formed through the cavity well bore 128. In one instance, the cavity 126 is formed using hydraulic or mechanical under reaming processes. The cavity 126 may be centered about the cavity well bore 128. As is seen in FIG. 2, the cavity well bore 128 may be drilled so that the cavity 126 can be formed offset from a corner of the access area 142 (whether or not the cavity well bore 128 originates offset from a corner of the access area 142).

The first portion 118 of the surface well bore 110 is drilled from about the surface 116 towards the subterranean zone 114. The first portion 118 may be located near a corner of the access area 142 (see FIG. 2). Directional drilling equipment 178 provided on a drill string 180 is then used to drill the curved portion 122. In one instance, the directional drilling equipment 178 includes a downhole steerable motor, such as a mud motor coupled to an adjustable bend or fix bend, bent sub, accelerometer based inclinometer, and magnetic guidance tools. The directional drilling equipment 178 is coupled to a drilling bit 176 such that the downhole steerable motor rotates the drilling bit 176. The bent sub points the downhole steerable motor and drilling bit 176 in a direction different from the axis of the preceding portions of the well bore drilled (i.e. first portion 118) when the drill string 180 is not being rotating. When rotated by the downhole steerable motor, the drill bit 176 drills in the direction it points. Therefore, by orienting the drill string 180 to point the bent sub in the desired direction, the drill bit 176 drills the curved portion 122 of the surface well bore 110. When the curved portion 122 is complete, the second portion 120 may be drilled substantially straight (in one instance, substantially horizontal) by rotating the entire drill string 180 while operating the downhole steerable motor to rotate the drill bit 176. Rotating the drill string 180 sweeps the bent sub through 360 degrees and the drill bit 176 does not drill in a single direction off the well bore axis, but rather sweeps around with the bent sub and drills in a net direction that is substantially straight. If the bent sub is adjustable, the angle of the bent sub can be set to 0 degrees relative to the axis of the well bore to drill a substantially straight well bore without rotating the drilling string 180. Although described herein with respect to a sliding steerable motor and bent sub, it is within the scope of the concepts described herein to use rotary steerable tools to directional drill.

In some instances, upon completion of all or some portion of the surface well bore 110, a casing 124 can be positioned (and optionally cemented in place) in the surface well bore 110 or portions thereof.

A first of the secondary well bores 112 is drilled extending from the second portion 120 of the surface well bore 110. In one instance, as shown in the figures, the first drilled secondary well bore 112 is drilled substantially straight out from the end of the second portion 120 of the surface well bore 110, through the cavity 126 and diagonally to a distant corner of the specified access area 142 (FIG. 3). When the first drilled secondary well bore 112 is complete, a liner system 10 can be positioned in the first drilled secondary well bore 112 using liner running tool 12 and working string 26. The whipstock surface 40 is positioned about the desired origination (i.e. kick off) location of the second secondary well bore 112 to be drilled. Furthermore, as the liner system 10 is being positioned in the first drilled secondary well bore 112 or after the liner system 10 is in position, the liner running tool 12 can be rotated via of the working string 26 to orient the whipstock surface 40. In FIG. 4, the whipstock surface 40 is oriented to deflect drilling operations downwardly from the longitudinal axis of the first drilled secondary well bore 112.

The second drilled secondary well bore 112 originates (i.e. kicks off) from the second portion 120 of the surface well bore 110. The second drilled secondary well bore 112 can be termed a lateral well bore to the second portion 120, because it deviates laterally from the second portion 120. If drilled with the directional drilling equipment 178 discussed above, the drill string 180 is rotated to orient the drill bit 176 in the desired kick off direction. The drill bit 176 is rotated to begin drilling, and the drill string 180 is pushed axially further into the second portion 120. The drill bit 176 and drill string 180 deflect off of the whipstock surface 40 into the sidewall of the well bore and begin drilling the second drilled secondary well bore 112. Thereafter, the orientation of the drill string 180 may be periodically adjusted and/or the drill string 180 may be rotated as discussed above to control the desired path of the second drilled secondary well bore 112. The second drilled secondary well bore 112 is drilled to diverge from (substantially vertically below) the first drilled secondary well bore 112 for a distance, substantially track the first drilled secondary well bore 112 for a distance, intersect the cavity 126, and as is seen in FIG. 3 further diverge from (substantially horizontally to the side) the first drilled secondary well bore 112 to an intermediate boundary of the specified access area 142.

Turning now to FIG. 5, when the second of the secondary well bores 112 is complete, the drill string 180 is withdrawn to the surface 116, and a second liner system 10 is positioned in the second drilled secondary well bore 112 using the liner running tool 12 and working string 26. The second liner system 10 deflects off of the whipstock surface 40 of the liner positioned in the first drilled secondary well bore 112 as it is run into the second drilled secondary well bore 112. The whipstock surface 40 of the second liner system 10 is positioned about the desired kickoff location of the third secondary well bore 112 to be drilled. In FIG. 5, the liner system 10 extends into the second portion 120 of the surface well bore 110. As the liner system 10 is being positioned in the second drilled secondary well bore 112 or after the liner system 10 is in position, the liner running tool 12 can be rotated via the working string 26 to orient the whipstock surface 40. In FIG. 5, the whipstock surface 40 is oriented to deflect drilling operations downwardly from the longitudinal axis of the second portion 120 of the surface well bore 110.

The third drilled secondary well bore 112 kicks off from the second portion 120 of the surface well bore 110. The third drilled secondary well bore 112 can be termed a lateral well bore to the second portion 120, because it deviates laterally from the second portion 120. The drill bit 176 is rotated to begin drilling and the drill string 180 is pushed axially into the second portion 120. The drill bit 176 and drill string 180 deflect off the whipstock surface 40 into the sidewall of the well bore and begin drilling the third drilled secondary well bore 112. The third drilled secondary well bore 112 is drilled to diverge from (substantially vertically below) the second drilled secondary well bore 112 for a distance, substantially track the second drilled secondary well bore 112 for a distance, intersect the cavity 126 and as is seen in FIG. 3 further diverge from (substantially horizontally to the side) the second drilled secondary well bore 112 to an intermediate boundary of the specified access area 142.

When the third drilled secondary well bore 112 is complete, a liner 138 may be positioned within the third drilled secondary well bore 112. The liner 138 may be provided to terminate in or about the casing 124. In one instance, the liner 138 can be provided with a packer 144 that substantially seals the annulus between the liner 138 and the casing 124.

It should be clear from the discussion above that additional well bores beyond the three secondary well bores 112 discussed above, or fewer well bores can be formed.

Upon completion of the secondary well bores 112, the cavity 126 is gravel packed and the apertured liner section 152 is installed. The pump inlet 144 can be positioned in the sump 134, the cavity 126 or the cavity well bore 128, and the pump 146 operated to withdraw fluid and fines to the surface while the subterranean zone 114 is produced either through the surface well bore 110 or through the cavity well bore 128. The setting collars 16 (and thus whipstock surfaces 40) of each liner system 10 installed in the secondary well bores 112 remain in the secondary well bores 112 indefinitely, and at least during production. Accordingly, fluids from the subterranean zone 14 that enter the liner tubings 18 may flow through the interior of the setting collars 16 to the surface if some or all of the fluids of the subterranean zone 114 are produced through the surface well bore 110.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Whipstock liner

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CPC

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