Unitary lateral leg with three or more openings

Provided is a multilateral leg bore, a multilateral junction, and a well system. The multilateral leg bore, in one aspect, includes a unitary housing having a first end and a second opposing end defining a length (L). In accordance with this aspect, the multilateral junction includes three or more bores formed in the housing and extending along the length (L).

BACKGROUND

A variety of selective borehole pressure operations require pressure isolation to selectively treat specific areas of the wellbore. One such selective borehole pressure operation is horizontal multistage hydraulic fracturing (“frac” or “fracking”). In multilateral wells, the multistage stimulation treatments are performed inside multiple lateral wellbores. Efficient access to all lateral wellbores is critical to complete successful pressure stimulation treatment.

DETAILED DESCRIPTION

In the drawings and descriptions that follow, like parts are typically marked throughout the specification and drawings with the same reference numerals, respectively. The drawn figures are not necessarily to scale. Certain features of the disclosure may be shown exaggerated in scale or in somewhat schematic form and some details of certain elements may not be shown in the interest of clarity and conciseness. The present disclosure may be implemented in embodiments of different forms.

Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed herein may be employed separately or in any suitable combination to produce desired results.

Unless otherwise specified, use of the terms “connect,” “engage,” “couple,” “attach,” or any other like term describing an interaction between elements is not meant to limit the interaction to a direct interaction between the elements and may also include an indirect interaction between the elements described. Unless otherwise specified, use of the terms “up,” “upper,” “upward,” “uphole,” “upstream,” or other like terms shall be construed as generally toward the surface of the ground; likewise, use of the terms “down,” “lower,” “downward,” “downhole,” or other like terms shall be construed as generally toward the bottom, terminal end of a well, regardless of the wellbore orientation. Use of any one or more of the foregoing terms shall not be construed as denoting positions along a perfectly vertical axis. In some instances, a part near the end of the well can be horizontal or even slightly directed upwards. In such instances, the terms “up,” “upper,” “upward,” “uphole,” “upstream,” or other like terms shall be used to represent the toward the surface end of a well. Unless otherwise specified, use of the term “subterranean formation” shall be construed as encompassing both areas below exposed earth and areas below earth covered by water such as ocean or fresh water.

A particular challenge for the oil and gas industry is developing a pressure tight TAML (Technology Advancement of Multilaterals) level 5 multilateral junction that can be installed in casing (e.g., 7 ⅝″ casing) and that also allows for ID access (e.g., 3 ½″ ID access) to a main wellbore after the junction is installed. This type of multilateral junction could be useful for coiled tubing conveyed stimulation and/or clean-up operations. It is envisioned that future multilateral wells will be drilled from existing slots/wells where additional laterals are added to the existing wellbore. If a side track can be made from the casing (e.g., 9 ⅝″ casing), there is an option to install a liner (e.g., 7″ or 7 ⅝″ liner) with a new casing exit point positioned at an optimal location to reach undrained reserves.

Referring now toFIG.1, illustrated is a diagram of a well system100for hydrocarbon reservoir production, according to certain example embodiments. The well system100in one or more embodiments includes a pumping station110, a main wellbore120, tubing130,135, which may have differing tubular diameters, and a plurality of multilateral junctions140, and lateral legs150with additional tubing integrated with a main bore of the tubing130,135. Each multilateral junction140may comprise a junction designed, manufactured or operated according to the disclosure, including a multilateral bore leg according to the disclosure. The well system100may additionally include a control unit160. The control unit160, in this embodiment, is operable to control to and/or from the multilateral junctions and/or lateral legs150, as well as other devices downhole.

Turning toFIG.2Aillustrated is a perspective view of a multilateral junction200designed, manufactured and operated according to one or more embodiments of the disclosure. The multilateral junction200, in the illustrated embodiment, includes without limitation a y-block210, a mainbore leg240, and a lateral bore leg260.

The y-block210may include a housing220. For example, the housing220could be a solid piece of metal having been milled to contain various different bores according to the disclosure. In another embodiment, the housing220is a cast metal housing formed with the various different bores according to the disclosure. The housing220, in accordance with one embodiment, may include a first end222and a second opposing end224. The first end222, in one or more embodiments, is a first uphole end, and the second end224, in one or more embodiments, is a second downhole end.

The y-block210, in one or more embodiments, includes a single first bore225extending into the housing220from the first end222. The y-block210, in one or more embodiments, further includes a second bore230and a third bore235extending into the housing220. In the illustrated embodiment the second bore230and the third bore235branch off from the single first bore225at a point between the first end222and the second opposing end224. In accordance with one embodiment of the disclosure, the second bore230defines a second centerline and the third bore235defines a third centerline. The second centerline and the third centerline may have various different configurations relative to one another. In one embodiment the second centerline and the third centerline are parallel with one another. In another embodiment, the second centerline and the third centerline are angled relative to one another, and for example relative to the first centerline.

The lateral bore leg260, in the illustrated embodiment, includes a unitary housing262. The unitary housing262, in the illustrated embodiment, has a first end264and a second opposing end266defining a length (L). The length (L) of the lateral bore leg260may vary greatly and remain within the scope of the disclosure.

Turning toFIG.2Bwith continued reference toFIG.2A, illustrated is a cross-sectional view of the lateral bore leg260(e.g., multilateral bore leg) taken through the line2B-2B ofFIG.2A. The lateral bore leg260, in the illustrated embodiment, includes the unitary housing262. Located within the unitary housing262, in the illustrated embodiment, are three or more bores270, the three or more bores270formed in the unitary housing262and extending along the length (L). In the illustrated embodiment ofFIG.2B, the lateral bore leg260includes a center bore270c, a right bore270r, and a left bore270l. In the illustrated embodiment, a centerpoint of each of the center bore270c, right bore270rand left bore270lare laterally offset from one another. Further to this embodiment, the centerpoint of the center bore270cis horizontally offset from the right bore270rand the left bore270l. In the embodiment ofFIG.2B, the center bore270c, right bore270rand left bore270ldo not overlap one another, and thus provide three separate flow paths and three separate tool paths.

Further to the embodiment ofFIG.2B, the center bore270chas a diameter (dc), the right bore270rhas a diameter (dr), and the left bore270lhas a diameter (dl). While not specifically required, in the embodiment ofFIG.2B, the diameter (dc) is greater than the diameters (dr) and (dl). Other embodiments exist wherein the diameter (dc) is not greater than the diameters (dr) and (dl), or alternatively wherein the diameter (dc) is less than the diameters (dr) and (dl).

In certain embodiments, such as that illustrated inFIG.2B, the unitary housing262is generally D-shaped, thereby having one somewhat straight surface and an opposing curved surface. The unitary housing262illustrated inFIG.2Bhas an inner radial profile (ri) and an outer radial profile (ro). In at least one embodiment, the outer radial profile (ro) is operable to mimic an outer radial profile of the y-block210. The outer radial profile (ro) may range greatly, but in one or more embodiments the outer radial profile (ro) ranges from about 2.5 cm to about 30 cm (e.g., from about 1 inches to about 12 inches). The outer radial profile (ro), in one or more embodiments, ranges from about 3.8 cm to about 20.3 cm (e.g., from about 1.5 inches to about 8 inches). In yet another embodiment, the outer radial profile (ro) may range from about 7.6 cm to about 15.3 cm (e.g., from about 3 inches to about 6 inches). In yet another embodiment, the outer radial profile (ro) may range from about 8.9 cm to about 12.7 cm (e.g., from about 3.5 inches to about 5 inches), and more specifically in one embodiment a value of about 11.4 cm (e.g., about 4.5 inches). Furthermore, in at least one embodiment, the inner radial profile (ri) is operable to hug a radius of a mainbore leg240as the pair are being deployed. Accordingly, the inner radial profile (ri) would have similar values as an outer radius of the mainbore leg240.

The unitary housing262may additionally have an inner thickness (ti), for example where the center bore270capproaches the inner radial profile (ri). The unitary housing may additionally have an outer thickness (to), for example where the center bore270capproaches the outer radial profile (ro). In designing the lateral bore leg260, the diameter (dc) of the center bore270cmay be maximized such that an acceptable inner thickness (ti) and outer thickness (to) are achieved, and that the lateral bore leg260can handle the necessary stresses placed thereon. Similarly, a wall thickness (t) may exist between the center bore270cand the right and left bores270r,270l. In designing the lateral bore leg260, the diameter (dc) of the center bore270cmay be maximized such that an acceptable wall thickness (t) is achieved, and that the lateral bore leg260can handle the necessary stresses placed thereon.

Turning toFIG.2C, illustrated is a stress map of the lateral bore leg260illustrated inFIG.2B. Note, in the embodiment ofFIG.2C, the highest stresses are experienced proximate the wall thickness (t). Accordingly, the lateral bore leg260has maximized the flow area, while at the same time keeping the stresses to acceptable values.

The lateral bore leg260, in one or more embodiments, is a high pressure lateral bore leg. For example, in at least one embodiment, the lateral bore leg260is capable of withstanding at least 5,000 psi burst rate. In yet another example, the lateral bore leg2600is capable of withstanding at least 10,000 psi burst rate. In at least one embodiment, the lateral bore leg260is capable of withstanding at least 4,000 psi collapse rate. In yet another example, the lateral bore leg260is capable of withstanding at least 7000 psi collapse rate. Accordingly, the lateral bore leg260may be employed to access and fracture one or both of the main wellbore and/or lateral wellbore. For example, the lateral bore leg260could have the necessary pressure ratings, outside diameters, and inside diameters necessary to run a fracturing string there through, and thereafter appropriately and safely fracture one or both of the main wellbore and/or lateral wellbore. Moreover, the lateral bore leg260would ideally have a yield strength of at least 80 ksi, so as to meet the NACE standard.

Turning toFIG.3, illustrated is a cross-sectional view of an alternative embodiment of lateral bore leg360. The lateral bore leg360ofFIG.3is similar in many respects to the lateral bore leg260illustrated inFIG.2B. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The lateral bore leg360differs for the most part from the lateral bore leg260, in that a centerpoint of each of the center bore370c, right bore370rand left bore370lare laterally offset from one another, and the centerpoint of the center bore370c, right bore370rand left bore370lare horizontally aligned with each other. Further to the embodiment ofFIG.3, the diameter (dc), diameter (dr), and diameter (dl) equal each other.

Turning toFIG.4, illustrated is a cross-sectional view of an alternative embodiment of lateral bore leg460. The lateral bore leg460ofFIG.4is similar in many respects to the lateral bore leg260illustrated inFIG.2B. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The lateral bore leg460differs for the most part from the lateral bore leg260, in that the diameter (dc), the diameter (dr) and the diameter (dl) differ from each other, and furthermore the diameter (dc) is the largest diameter.

Turning toFIG.5, illustrated is a cross-sectional view of an alternative embodiment of lateral bore leg560. The lateral bore leg560ofFIG.5is similar in many respects to the lateral bore leg260illustrated inFIG.2B. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The lateral bore leg560differs for the most part from the lateral bore leg260, in that the diameter (dc) is the smallest diameter, and furthermore the diameter (dr) and diameter (dl) equal each other.

Turning toFIG.6A, illustrated is a cross-sectional view of an alternative embodiment of lateral bore leg660A. The lateral bore leg660A ofFIG.6Ais similar in many respects to the lateral bore leg260illustrated inFIG.2B. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The lateral bore leg660A differs for the most part from the lateral bore leg260, in that the center bore670c, right bore670rand left bore670loverlap one another to provide a single combined flow path but three separate tool paths.

Turning toFIG.6B, illustrated is a cross-sectional view of an alternative embodiment of lateral bore leg660B. The lateral bore leg660B ofFIG.6Bis similar in many respects to the lateral bore leg660A illustrated inFIG.6A. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The lateral bore leg660B ofFIG.6Bdiffers for the most part from the lateral bore leg660A ofFIG.6A, in that the unitary housing262does not include the inner radial profile (ri). Accordingly, the unitary housing262ofFIG.6Bcloser to a D-shape than the unitary housing262ofFIG.6A.

Turning now toFIGS.7through19, illustrated is a method for forming, intervening, fracturing and/or producing from a well system700.FIG.7is a schematic of the well system700at the initial stages of formation. A main wellbore710may be drilled, for example by a rotary steerable system at the end of a drill string and may extend from a well origin (not shown), such as the earth's surface or a sea bottom. The main wellbore710may be lined by one or more casings715,720, each of which may be terminated by a shoe725,730.

The well system700ofFIG.7additionally includes a main wellbore completion740positioned in the main wellbore710. The main wellbore completion740may, in certain embodiments, include a main wellbore liner745(e.g., with frac sleeves in one embodiment), as well as one or more packers750(e.g., swell packers in one embodiment). The main wellbore liner745and the one or more packer750may, in certain embodiments, be run on an anchor system760. The anchor system760, in one embodiment, includes a collet profile765for engaging with the running tool790, as well as a muleshoe770(e.g., slotted alignment muleshoe). A standard workstring orientation tool (WOT) and measurement while drilling (MWD) tool may be coupled to the running tool790, and thus be used to orient the anchor system760.

Turning toFIG.8, illustrated is the well system700ofFIG.7after positioning a whipstock assembly810downhole at a location where a lateral wellbore is to be formed. The whipstock assembly810includes a collet820for engaging the collet profile765in the anchor system760. The whipstock assembly810additionally includes one or more seals830(e.g., a wiper set in one embodiment) to seal the whipstock assembly810with the main wellbore completion740. In certain embodiments, such as that shown inFIG.8, the whipstock assembly810is made up with a lead mill840, for example using a shear bolt, and then run in hole on a drill string850. The WOT/MWD tool may be employed to confirm the appropriate orientation of the whipstock assembly810.

Turning toFIG.9, illustrated is the well system700ofFIG.8after setting down weight to shear the shear bolt between the lead mill840and the whipstock assembly810, and then milling an initial window pocket910. In certain embodiments, the initial window pocket910is between 1.5 m and 3.0 m long, and in certain other embodiments about 2.5 m long, and extends through the casing720. Thereafter, a circulate and clean process could occur, and then the drill string850and lead mill840may be pulled out of hole.

Turning toFIG.10, illustrated is the well system700ofFIG.9after running a lead mill1020and watermelon mill1030downhole on a drill string1010. In the embodiments shown inFIG.10, the drill string1010, lead mill1020and watermelon mill1030drill a full window pocket1040in the formation. In certain embodiments, the full window pocket1040is between 6 m and 10 m long, and in certain other embodiments about 8.5 m long. Thereafter, a circulate and clean process could occur, and then the drill string1010, lead mill1020and watermelon mill1030may be pulled out of hole.

Turning toFIG.11, illustrated is the well system700ofFIG.10after running in hole a drill string1110with a rotary steerable assembly1120, drilling a tangent1130following an inclination of the whipstock assembly810, and then continuing to drill the lateral wellbore1140to depth. Thereafter, the drill string1110and rotary steerable assembly1120may be pulled out of hole.

Turning toFIG.12, illustrated is the well system700ofFIG.11after employing an inner string1210to position a lateral wellbore completion1220in the lateral wellbore1140. The lateral wellbore completion1220may, in certain embodiments, include a lateral wellbore liner1230(e.g., with frac sleeves in one embodiment), as well as one or more packers1240(e.g., swell packers in one embodiment). Thereafter, the inner string1210may be pulled into the main wellbore710for retrieval of the whipstock assembly810.

Turning toFIG.13, illustrated is the well system700ofFIG.12after latching a whipstock retrieval tool1310of the inner string1210with a profile in the whipstock assembly810. The whipstock assembly810may then be pulled free from the anchor system760, and then pulled out of hole. What results are the main wellbore completion740in the main wellbore710, and the lateral wellbore completion1220in the lateral wellbore1140.

Turning toFIG.14, illustrated is the well system700ofFIG.13after employing a running tool1410to install a deflector assembly1420proximate a junction between the main wellbore710and the lateral wellbore1140. The deflector assembly1420may be appropriately oriented using the WOT/MWD tool. The running tool1410may then be pulled out of hole.

Turning toFIG.15, illustrated is the well system700ofFIG.14after employing a running tool1510to place a multilateral junction1520proximate an intersection between the main wellbore710and the lateral wellbore1410. In accordance with one embodiment, the multilateral junction1520could be similar to one or more of the multilateral junctions discussed above with respect toFIGS.2through6. Accordingly, while not clearly illustrated in the embodiment ofFIG.15as result of the scale of the drawings, the multilateral junction1520could have the aforementioned lateral well bore as discussed above.

Turning toFIG.16, illustrated is the well system700ofFIG.15after selectively accessing the main wellbore710with a first intervention tool1610through the y-block of the multilateral junction1520. In the illustrated embodiment, the first intervention tool1610is a fracturing tool, and more particularly a coiled tubing conveyed fracturing tool. With the first intervention tool1610in place, fractures1620in the subterranean formation surrounding the main wellbore completion740may be formed. Thereafter, the first intervention tool1610may be pulled from the main wellbore completion740.

Turning toFIG.17, illustrated is the well system700ofFIG.16after positioning a downhole tool1710within the multilateral junction1520including the y-block. In the illustrated embodiment, the downhole tool1710is a fracturing tool, and more particularly a coiled tubing conveyed fracturing tool.

Turning toFIG.18, illustrated is the well system700ofFIG.17after putting additional weight down on the second intervention tool1710and causing the second intervention tool1710to enter the lateral wellbore1140. With the downhole tool1710in place, fractures1820in the subterranean formation surrounding the lateral wellbore completion1220may be formed. In certain embodiments, the first intervention tool1610and the second intervention tool1710are the same intervention tool. Thereafter, the second intervention tool1710may be pulled from the lateral wellbore completion1220and out of the hole.

Turning toFIG.19, illustrated is the well system700ofFIG.18after producing fluids1910from the fractures1620in the main wellbore710, and producing fluids1920from the fractures1820in the lateral wellbore1140. The producing of the fluids1910,1920occur through the multilateral junction1520, and more specifically through the y-block design, manufactured and operated according to one or more embodiments of the disclosure.

Aspects Disclosed Herein Include:

A. A multilateral bore leg, the multilateral bore leg including: 1) a unitary housing having a first end and a second opposing end defining a length (L); and 2) three or more bores formed in the housing and extending along the length (L).

B. A multilateral junction, the multilateral junction including: 1) a y-block, the y-block including; a) a housing having a first end and a second opposing end; b) a single first bore extending into the housing from the first end, the single first bore defining a first centerline; and c) second and third separate bores extending into the housing and branching off from the single first bore, the second bore defining a second centerline and the third bore defining a third centerline; 2) a mainbore leg coupled to the second bore for extending into the main wellbore; and 3) a lateral bore leg coupled to the third bore for extending into the lateral wellbore, the lateral bore leg including; a) a unitary housing having a first end and a second opposing end defining a length (L); and b) three or more bores formed in the housing and extending along the length (L).

C. A well system, the well system including: 1) a main wellbore; 2) a lateral wellbore extending from the main wellbore; 3) a multilateral junction positioned at an intersection of the main wellbore and the lateral wellbore, the multilateral junction including; 1) a y-block, the y-block including; i) a housing having a first end and a second opposing end; ii) a single first bore extending into the housing from the first end, the single first bore defining a first centerline; and iii) second and third separate bores extending into the housing and branching off from the single first bore, the second bore defining a second centerline and the third bore defining a third centerline; b) a mainbore leg coupled to the second bore for extending into the main wellbore; and c) a lateral bore leg coupled to the third bore for extending into the lateral wellbore, the lateral bore leg including; i) a unitary housing having a first end and a second opposing end defining a length (L); and ii) three or more bores formed in the housing and extending along the length (L).

Aspects A, B, and C may have one or more of the following additional elements in combination: Element 1: wherein the unitary housing has a center bore, a right bore, and a left bore. Element 2: wherein a centerpoint of each of the center bore, right bore and left bore are laterally offset from one another, and the centerpoint of the center bore is horizontally offset from the right bore and the left bore. Element 3: wherein a centerpoint of each of the center bore, right bore and left bore are laterally offset from one another, and the centerpoint of the center bore, right bore and left bore are horizontally aligned with each other. Element 4: wherein the center bore has a diameter (dc), the right bore has a diameter (dr), and the left bore has a diameter (dl), and further wherein the diameter (dc) is greater than the diameters (dr) and (dl). Element 5: wherein the center bore has a diameter (dc), the right bore has a diameter (dr), and the left bore has a diameter (dl), and further wherein the diameter (dc), diameter (dr), and diameter (dl) equal each other. Element 6: wherein the center bore has a diameter (dc), the right bore has a diameter (dr), and the left bore has a diameter (dl), and further wherein the diameter (dc), the diameter (dr) and the diameter (dl) differ from each other, the diameter (dc) being the largest diameter. Element 7: wherein the center bore has a diameter (dc), the right bore has a diameter (dr), and the left bore has a diameter (dl), and further wherein the diameter (dc) is the smallest diameter and the diameter (dr), and diameter (dl) equal each other. Element 8: wherein the center bore, right bore and left bore do not overlap one another, and thus provide three separate flow paths and three separate tool paths. Element 9: wherein the center bore, right bore and left bore overlap one another to provide a single combined flow path but three separate tool paths. Element 10: wherein the housing is generally D-shaped. Element 11: wherein the generally D-shaped housing has an inner radial profile (ri) and an outer radial profile (ro). Element 12: wherein the outer radial profile (ro) is operable to mimic an outer radial profile of a y-block the multilateral bore leg is coupled to. Element 13: wherein the inner radial profile (ri) is operable to hug a radius of a mainbore leg the multilateral bore leg is deployed with. Element 14: wherein the mainbore leg couples to the second bore using one or more threads, and further wherein the lateral bore leg couples to the third bore using something other than the one or more threads. Element 15: wherein the unitary housing has a center bore, a right bore, and a left bore, and further wherein centerpoint of each of the center bore, right bore and left bore are laterally offset from one another, and the centerpoint of the center bore is horizontally offset from the right bore and the left bore. Element 16: wherein the center bore has a diameter (dc), the right bore has a diameter (dr), and the left bore has a diameter (dl), and further wherein the diameter (dc) is greater than the diameters (dr) and (dl). Element 17: wherein the center bore, right bore and left bore do not overlap one another, and thus provide three separate flow paths and three separate tool paths. Element 18: wherein the center bore, right bore and left bore overlap one another to provide a single combined flow path but three separate tool paths.