Baker Hughes Corporation

Brian S Kennedy

Henry J Jordan, Jr

Alan B Emerson

Patrick James Zimmerman

Robert J McNair

A method for completing multi-lateral wells and maintaining selective re-entry into laterals is presented. In accordance with the present invention, a first lateral well is drilled from a primary well bore and a string of external casing packers and a packer bore receptacle are run therein. Once the orientation of the packer bore receptacle is determined, an orientation anchor of a retrievable whipstock assembly is mounted thereto. Thereafter, a second lateral well may be drilled. Once the second lateral well is drilled, the whipstock assembly may be retrieved and replaced with a scoophead diverter assembly which also includes an orientation anchor for mating with the packer bore receptacle. At this time, a string of external casing packers may be run into the second lateral well through the scoophead diverter assembly. Finally, a selective reentry tool is run into the scoophead assembly. The selective re-entry tool includes a diversion flapper for selecting either the first or second lateral well bore. Selective re-entry is desirable for the purpose of performing well intervention techniques. The re-entry tool may be actuated by a device located on a coil tubing work string which may be operated from the surface.

Method for completing multi-lateral wells and maintaining selective

A scoophead/diverter assembly functions to orient and anchor multiple tubing strings at the Y-juncture in an oil or gas well with multiple lateral wellbores. An important advantage of this arrangement is to provide communication to multiple reservoirs or tap different locations within the same reservoir, and enable re-entry to these wellbores for remediation and stimulation. The large bore of the scoophead enables a secondary wellbore's production tubing (liner) to pass through until the top of the liner is in the scoophead. In order to effect a seal inside the scoophead, a novel offset parallel seal assembly with centralizer is utilized. This parallel seal assembly carries compressive loads on the primary wellbore side, and has a shear out mechanism on the secondary wellbore side. This seal assembly also may constitute the connection between the scoophead and a selective re-entry tool (SRT). The SRT is a tool that ties the two separate tubing strings below it into a single production tubing string to surface or the next lateral. This parallel seal assembly has two seal assemblies parallel to one another with one seal assembly being larger diameter and longer than the other. The larger seal assembly seals into the seal bore of a tie back sleeve which is latched into the scoophead, and is attached to the top of the secondary wellbore's production tubing string. The smaller seal assembly seals in the small bore of the scoophead. The smaller assembly acts to isolate the primary wellbore. The larger seal assembly is longer than the smaller to allow it to enter its bore and align the assembly. The alignment is accomplished by trapping the larger seal assembly in its bore and trapping the centralizer in the wellbore. This positively limits the rotational mis-alignment available to the smaller seal assembly prior to stabbing into the scoophead.

Parallel seal assembly

A novel scoophead/diverter assembly is presented which is installed at the juncture between a primary wellbore and a lateral branch and which allows the production tubing of each to be oriented and anchored. This scoophead/diverter assembly further provides dual seal bores for tying back to the surface with either a dual packer completion or a single tubing string completion utilizing a selective re-entry tool. The scoophead/diverter assembly comprises a scoophead, a diverter sub, two struts as connecting members between the scoophead and diverter sub and a joint of tubing communicating from the scoophead, thru the diverter sub, and to the primary wellbore. The scoophead has a large and small bore. The large bore is a receptacle for a tie back sleeve run on top of the lateral wellbore string, and the small bore is a seal bore to tie the primary wellbore back to surface. Below the scoophead, a joint of tubing is threaded to the small bore. The tubing passes through an angled smooth bore in the diverter sub which causes the tubing joint to deflect from the offset of the small bore of the scoophead back to the centerline of the scoophead, and thus the centerline of the borehole with which it is concentric. In accordance with an important feature of the scoophead, the profile in the top of the scoophead is configured so that it directs the production tubing for the lateral wellbore into the large bore of the scoophead and also orients a parallel seal assembly when tying back to the surface with a dual packer completion or a single tubing completion. The orientation is accomplished by combining a sloped profile with a slotted inclined surface around the small bore and a compound angled surface above the slot.

Scoophead/diverter assembly for completing lateral wellbores

A novel lateral connector receptacle or LCR is provided which functions to (1) provide means for running a lower completion into a well; (2) provide means for orienting a retrievable whipstock assembly and/or scoophead diverter; and (3) provides means for attaching an upper completion to a lower completion. The LCR includes an upper section having a latch thread and smooth seal bore which respectively threadably attaches to, and mates with seals from, an orientation anchor. A middle section of the LCR includes an orientation lug for mating with the orientation anchor and providing a fixed reference point to the retrievable whip stock and/or scoophead/diverter assembly; and a lower section includes an inner mating (e.g., profiled) surface for attachment to an appropriate run-in tool. Preferably, the LCR includes three cylindrical, threadably mated subs (which respectively include the (1) latch thread and seal bore; (2) the orientation anchor lug and (3) the profiled connecting surfaces) and a fourth bottom sub. The LCR combines all of the aforementioned features providing a novel tool which allows for the ability to stack infinite laterals in a single well.

Lateral connector receptacle

A scoophead/diverter assembly functions to orient and anchor multiple tubing strings at the Y-juncture in an oil or gas well with multiple lateral wellbores. An important advantage of this arrangement is to provide communication to multiple reservoirs or tap different locations within the same reservoir and enable re-entry to these wellbores for remediation and stimulation. The large bore of the scoophead enables a secondary wellbore's production tubing (liner) to pass through until the top of the liner is in the scoophead. In accordance with an important feature of this invention, a novel liner tie-back sleeve is used to thread onto the top of a lateral liner, and locate, latch and provide a seal receptacle to isolate the secondary wellbore's production fluids. The liner tie-back sleeve also includes a running profile for a suitable running tool. The liner tie-back sleeve comprises two cylindrical parts that, when assembled, provide a running tool profile for running the liner in the wellbore. The sleeve has a locating shoulder on the outer surface to indicate when the sleeve is located in the scoophead, and a locking groove for locking dogs from the scoophead to snap into to provide resistance when pulling tension against the sleeve. Once the sleeve is in place and the running tool removed, an internal latch thread and seal bore is exposed for a parallel seal assembly (or other tool or production tubing) to plug into for isolating the secondary lateral wellbore. Providing the seal point between the parallel seal assembly and sleeve eliminates the need to effect a seal in the scoophead on the large bore side.

Liner tie-back sleeve

A scoophead/diverter system is run into a wellbore using a novel scoophead running tool. The running tool allows circulation through its inside diameter, and has internal pressure integrity to test any seals below the running tool prior to releasing the scoophead. This also allows circulation while running in order to apply MWD techniques. This run-in tool includes a mounting head from which extends a running stump and a housing (or connecting mandrel) parallel to the running stump. The running stump and housing are sized and configured to be respectively received in large and small diameter bores in the scoophead. The scoophead running tool thus allows torque to be transmitted about the centerline of the scoophead assembly in spite of being attached into one of the offset bore. This torque transmission is accomplished by connecting the connecting mandrel between the running tool and scoophead at the same offset as the large bore of the scoophead. This transfer of torque is important in order to reliably manipulate the scoophead assembly with the running string. The connecting mandrel of the running tool has an internal bypass sleeve that opens at a predetermined pressure that allows a tripping ball to be circulated down to its seat if the scoophead is to run and be anchored into a closed system.

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Houston, TX, United States of America

Brian S Kennedy