Referring to
To continue drilling, the operator will install a drill-through tubing member on wellhead housing 11, and connect a drilling riser to the tubular member. In this embodiment, the drill-through tubular member comprises a horizontal tree 15, but it could comprise tubing spool instead. Tree 15 has a wellhead connector 17 on its lower end that is conventional and has dogs 19 that are actuated into engagement with an external profile on wellhead housing 11. In this example, tree 15 has an orientation sleeve 21 that extends downward from it for sliding into the bore of wellhead housing 11 above casing hanger 13. Orientation sleeve 21 has a helical groove 23 that is subsequently engaged by a key (not shown) of a tubing hanger assembly (not shown) to orient the tubing hanger relative to tree 15.
Tree 15 has an axial bore 25 that extends through it. In this example, the inner diameter of bore 25 is greater at the upper end and smaller at the lower end of tree 15, but the smallest inner diameter portion is essentially the same as the inner diameter of casing hanger 13. A production outlet 27 extends from the exterior of tree 15 to bore 25. A production valve 29 controls well fluid flowing out production passage 27. A lower tubing annulus 31 extends from bore 25 to the exterior of tree 15. Lower tubing annulus 31 communicates an annular space surrounding the tubing (not shown) with the exterior and has a valve 33. In this example, an upper tubing annulus passage 35 extends between bore 25 near the upper end of bore 25 to the exterior. A valve 37 within upper tubing annulus passage 35 controls fluid flow to upper tubing annulus passage 35. In addition, although not shown, ports will exist for supplying hydraulic fluid pressure to ports in the tubing hanger for delivery through lines to a downhole safety valve. Also, tree 15 may have one or more ports for electrical lines leading from the exterior to bore 25 for connection with temperature and pressure sensors and optionally an electrical submersible pump.
In some applications, a tubing spool would be employed rather than horizontal tree 15. A tubing spool would resemble tree 15 but it would not have a production passage 27. As a tubing spool, it would have a shoulder for landing a tubing hanger within, and it would have ports for hydraulic fluid and optionally electrical lines.
Prior to lowering tree 15 into the sea, a wear bushing 39 is installed within bore 25. Wear bushing 39 is a sleeve that provides protection to bore 25 against damage during drilling operations. Wear bushing 39 covers all of the ports or passages mentioned, including production outlet passage 27, and tubing annulus passages 31 and 35. Preferably wear bushing 39 has an upper shoulder 41 that lands on a mating shoulder in bore 25. Also, wear bushing 39 preferably has an upper seal 43 located above the point where upper tubing annulus passage 35 enters bore 25. A lower seal 45 locates below the point where lower tubing annulus 31 intersects bore 25. In this example, lower seal 45 is located in the inner diameter of orientation sleeve 21, which may be considered to be part of tree 15. Wear bushing 39 extends to the lower end of orientation sleeve 21 and covers helical groove 23, preferably.
Both the inner and outer diameters of wear bushing 39 may vary, as shown. The upper portion of the inner diameter is greater than the lower portion in this example, defining an upward facing tapered shoulder 46. The inner diameter of the lower portion of wear bushing 39 is equal or greater than the minimum inner diameter of any tubular structure located below, such as the inner diameter of the casing attached to casing hanger 13. The outer diameter of the upper portion of wear bushing 39 is also greater than the outer diameter of the lower portion, and the thickness of the upper portion is greater.
After landing tree 15, test fluid pressure can be applied to each port or passage 27, 31, 35 and those mentioned but not shown. This pressure exerts a radial inward force on wear bushing 39, tending to cause it to collapse.
In the embodiment of
A reaction member 61 is secured to stem 55 for engaging the inner diameter of at least a portion of wear bushing 39. Reacting member 61 is shown engaging a lower and thinner portion of wear bushing 39, but the position could differ. Reacting member 61 may have a variety of configurations and is rigid in the example of
In the method of
After testing, the operator rotates stem 55 in the opposite direction to allow locking element 51 to retract, or unlocks the interface hydraulically if tool 47 is hydraulically actuated. The operator pulls tool 47 from wear bushing 39 to the surface. The operator then connects a driller riser to tree 15 and commences further drilling of the well.
In the embodiment of
In the example of
A reacting member 73 is mounted to a lower portion of stem 55 for engagement with the inner diameter of wear bushing 39. In this embodiment, reacting member 73 is annular and has seals 75 on its exterior for sealing against the inner diameter of wear bushing 39. Optionally, seals 75 could be initially retracted or recessed within the outer diameter of reacting member 73. Ports 76 lead to the bases of the grooves containing seals 75 for supplying fluid pressure to push seals 75 outward into sealing engagement with wear bushing 39 at the appropriate time.
The annular space surrounding stem 71 between upper seal 69 and reacting member seal 75 comprises a sealed chamber 77. Supporting member 65 and seal 69 serve as an upper packer, and reacting member 73 and seal 75 serves as a lower packer. Stem 71 has an axial passage 79 extending downward. Passage 79 is closed at the lower end, and has one or more outlets 81 that lead from passage 79 to chamber 77. Preferably, each outlet 81 has a pressure relief valve 83 that allows flow from stem passage 79 to chamber 77 only when a selected pressure has been achieved. Seal energizing ports 76 communicate directly with stem passage 79.
In the operation of the embodiment of
The operator uses tool 63 to both test BOP 62 as well as prevent collapsing of wear bushing 39 during testing of tree valves 29, 33 and 37. BOP 62 is tested conventionally by closing element 64 around drill pipe 72 and pumping fluid through one of the choke and kill lines 66 into the chamber defined between test tool seal 69 and blowout preventer element 64. The operator may perform the blowout preventer test before or after testing valves 29, 33 and 37.
The dimensions of supporting member 65 may be selected to transfer the downward force on seal 69 during testing of BOP 62 through locking element 67 to tree 15 rather than to wear bushing rim 41 or vice-versa. Furthermore, if wear bushing 39 has sufficient strength to resist the downward force during BOP testing, and if the upward force component on wear bushing 39 during testing of the valves of tree 15 is not particularly high, locking element 67 could be eliminated.
To test the valves, the operator pumps fluid through drill pipe 72 and passage 79. Initially, pressure relief valves 83 will prevent fluid flow into chamber 77 until sufficient fluid pressure passes through seal energizing ports 76 to energize reacting member seals 75. Then, the fluid flows out pressure relief valves 83 and pressurizes chamber 77. The operator applies pressure to chamber 77 to a level that either matches the external test pressure to be applied to passages 27, 31 and 35 or creates a differential where the external test pressure is far in excess of the capabilities of wear bushing 39 and/or the annular void between the outer diameter of wear bushing 39 and tree bore 25. The pressure in chamber 77 exerts an outward force that counters the inward force caused by the test pressure to prevent collapsing of wear bushing 39. The upward force component on wear bushing 39 due to the valve test pressure is resisted by the engagement of locking element 67 with tree 15.
After completing the testing, the operator bleeds off the pressure in stem passage 79, which allows seals 75 to retract. Once retracted, the pressure within chamber 77 bleeds off below reacting member 73. The operator then retrieves tool 63 and commences drilling through the riser, BOP 62 and wear bushing 39 in a conventional manner. After the drilling has been completed, the operator runs casing and a casing hanger through riser and BOP 62 and the wear bushing 39. The operator would then complete the well by retrieving wear bushing 39 and installing a tubing hanger with a string of tubing, the tubing hanger landing on a shoulder in tree bore 25 above production passage 27.
Although shown as part of a BOP isolation test tool, tool 63 could alternatively be used as a running tool for tree 15. In that instance, supporting member 65 would be interchanged with connector 49 of
The operator would not want to retrieve wear bushing 39 prior to drilling through tree 15, rather the retrieval occurs just before running the tubing hanger. Normally, a conventional retrieval tool is employed to retrieve wear bushing 39, but this requires an extra trip of the running string just for retrieval. By changing out reacting member 73 (
In the example shown, reacting member 73′ and gripping member 82 are not used during the initial testing immediately after landing tree 15, as mentioned. Rather than provide two separate reacting members 73 and 73′, a gripping member (not shown) could be employed in a manner such that it remains retracted during the initial testing and retrieval. The gripping member could be selectively energized, for example, by rotating the drill string in a reverse direction after the tree valve testing had been completed.
A plurality of elongated segments 91 are carried by stem 89. Segments 91 are spaced around the circumference of stem 89 and are configured to fit closely within the inner diameter of wear bushing 39. Each segment 91 has a tapered shoulder 92 on its exterior that lands on wear bushing shoulder 46. Segments 91 define an annular member with a central bore 93 of varying inner diameter. An upper annular wedge member 95 and a lower annular wedge member 97 are rigidly connected to stem 89. In this example, the conical sidewalls of wedge members 95, 97 taper to a reduced diameter in a downward direction. Central bore 93 has an upper tapered section 99 and a lower tapered section 101 that are engaged by wedge members 95, 97 when stem 89 moves downward.
In the operation of the third embodiment, tool 85 is preferably lowered through the riser and BOP 62 (
After the testing is completed, the operator retrieves tool 85 by lifting stem 89, causing it to move upward relative to segments 91. This removes the engagement of upper and lower wedge members 95, 97 with upper and lower tapered surfaces 99 and 101.
A gripping member similar to gripping member 82 of
Referring to
The operator utilizes tool 103 by pumping fluid from the surface down the drill string into stem passage 113 to inflate bladder 111. Once inflated, the operator will test valves 29, 33 and 37 in the same manner as described in connection with the other embodiments.
The invention has significant advantages. The tool allows a thin wear bushing to be used, which provides a large bore for drilling operations. The tool resists the external forces being applied to the wear bushing. Also, the tool can perform other functions to save trips. For example, the tool can be used to run the tree. The tool can alternately be used to test the blowout preventer. The tool can selectively retrieve the wear bushing during the same trip.
While the invention has been shown in a few of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention. As mentioned, rather than a tree, the tubular drill-through member could be a tubing spool, with the tree mounted on top of the tubing spool. The retrieval feature shown in