This application claims the benefit under 35 U.S.C. ยง119 of the filing date of International Application No. PCT/US2012/061201, filed Oct. 19, 2012.
This invention relates, in general, to equipment utilized in conjunction with operations performed in relation to subterranean wells and, in particular, to a gravel packing apparatus having a rotatable slurry delivery subassembly and a method for assembling the gravel packing apparatus on the rig floor.
Without limiting the scope of the present invention, its background is described with reference to a sand control completion in a wellbore traversing an unconsolidated or loosely consolidated subterranean formation, as an example.
It is well known in the subterranean well drilling and completion art that particulate materials such as sand may be produced during the production of hydrocarbons from a well traversing an unconsolidated or loosely consolidated subterranean formation. Numerous problems may occur as a result of the production of such particulate. For example, the particulate causes abrasive wear to components within the well, such as the tubing, pumps and valves. In addition, the particulate may partially or fully clog the well creating the need for an expensive workover. Also, if the particulate matter is produced to the surface, it must be removed from the hydrocarbon fluids by processing equipment at the surface.
One method for preventing the production of such particulate material to the surface is gravel packing the well adjacent the unconsolidated or loosely consolidated production interval. In a typical gravel pack completion, a sand control screen is lowered into the wellbore on a work string to a position proximate the desired production interval. A fluid slurry including a liquid carrier and a particulate material known as gravel is then pumped down the work string and into the well annulus formed between the sand control screen and the perforated well casing or open hole production zone.
The liquid carrier either flows into the formation or returns to the surface by flowing through the sand control screen or both. In either case, the gravel is deposited around the sand control screen to form a gravel pack, which is highly permeable to the flow of hydrocarbon fluids but blocks the flow of the particulate carried in the hydrocarbon fluids. As such, gravel packs can successfully prevent the problems associated with the production of particulate materials from the formation.
It has been found, however, that a complete gravel pack of the desired production interval is difficult to achieve particularly in long or inclined/horizontal production intervals. These incomplete packs are commonly a result of the liquid carrier entering a permeable portion of the production interval causing the gravel to form a sand bridge in the annulus. Thereafter, the sand bridge prevents the slurry from flowing to the remainder of the annulus which, in turn, prevents the placement of sufficient gravel in the remainder of the annulus.
Prior art devices and methods have been developed which attempt to overcome this sand bridge problem. For example, attempts have been made to use tubing positioned exteriorly along the length of the sand control screens to provide an alternate path for the fluid slurry around the sand bridge. It has been found, however, that it is difficult and time consuming to make all of the necessary fluid connections between the numerous alternate path tubing joints on the rig floor that are required for typical production intervals. Therefore, a need has arisen for an apparatus for gravel packing a production interval that overcomes the problems created by sand bridges. A need has also arisen for such an apparatus that is not difficult or time consuming to assemble on the rig floor.
The present invention disclosed herein is directed to a gravel packing apparatus having a rotatable slurry delivery subassembly for improved assembly of a gravel packing tool string on the rig floor. The gravel packing apparatus of the present invention is operable to overcome the problems created by sand bridges. In addition, the gravel packing apparatus of the present invention is not difficult or time consuming to assemble on the rig floor.
In one aspect, the present invention is directed to a gravel packing apparatus that includes a sand control screen assembly having a filter medium positioned exteriorly of a base pipe. The sand control screen assembly is operable to prevent the flow of particulate material of a predetermined size therethrough but allow the flow of production fluids therethrough. A slurry delivery subassembly is rotatably mounted exteriorly on the sand control screen assembly. The slurry delivery subassembly includes at least one transport tube extending longitudinally along at least a portion of the sand control screen assembly.
In one embodiment, the sand control screen assembly includes first and second circumferentially extending rails and the slurry delivery subassembly includes first and second ring assemblies. In this embodiment, the first ring assembly may be slidably positioned around the first rail and the second ring assembly may be slidably positioned around the second rail, thereby rotatably mounting the slurry delivery subassembly exteriorly on the sand control screen assembly. In another embodiment, the sand control screen assembly includes first and second threaded connectors and the slurry delivery subassembly includes first and second threaded ring assemblies. In this embodiment, the first threaded ring assembly may be threadably coupled to the first threaded connector and the second threaded ring assembly may be threadably coupled to the second threaded connector, thereby rotatably mounting the slurry delivery subassembly exteriorly on the sand control screen assembly.
In certain embodiments, a lock assembly may be positioned between the slurry delivery subassembly and the sand control screen assembly to selectively prevent relative rotation therebetween. The lock assembly may be one or more set screws, pins, a locking ring, a locking nut or the like. In some embodiments, an outer shroud may be positioned around the slurry delivery subassembly and the sand control screen assembly. In selected embodiments, the slurry delivery subassembly may include at least one packing tube having nozzles.
In another aspect, the present invention is directed to a gravel packing apparatus that includes first and second joints. Each joint includes a sand control screen assembly having a filter medium positioned exteriorly of a base pipe and a slurry delivery subassembly rotatably mounted exteriorly on the sand control screen assembly. The slurry delivery subassembly includes at least one transport tube extending longitudinally along at least a portion of the sand control screen assembly. At least one jumper tube is coupled to and extends between the at least one transport tube of the first joint and the at least one transport tube of the second joint. The at least one transport tube of the first joint is axially aligned with the at least one transport tube of the second joint by rotating the slurry delivery subassembly of the first joint relative to the sand control screen of the first joint after the sand control screen assembly of the first joint has been coupled to the sand control screen assembly of the second joint.
In another aspect, the present invention is directed to a method for assembling a gravel packing apparatus. The method includes providing first and second joints each including a sand control screen assembly having a filter medium positioned exteriorly of a base pipe and a slurry delivery subassembly rotatably mounted exteriorly on the sand control screen assembly, the slurry delivery subassembly including at least one transport tube extending longitudinally along at least a portion of the sand control screen assembly; threadably coupling the sand control screen assembly of the first joint to the sand control screen assembly of the second joint; axially aligning the at least one transport tube of the first joint with the at least one transport tube of the second joint by rotating the slurry delivery subassembly of the first joint relative to the sand control screen of the first joint; and coupling at least one jumper tube between the at least one transport tube of the first joint and the at least one transport tube of the second joint.
The method may also includes locking the slurry delivery subassembly of the second joint relative to the sand control screen of the second joint prior to axially aligning the at least one transport tube of the first joint with the at least one transport tube of the second join; locking the slurry delivery subassembly of the first joint relative to the sand control screen of the first joint after axially aligning the at least one transport tube of the first joint with the at least one transport tube of the second joint; sliding first and second ring assemblies of the slurry delivery subassembly on first and second rails of the sand control screen assembly; rotating first and second threaded ring assemblies of the slurry delivery subassembly on first and second threaded connectors of the sand control screen assembly; establishing fluid communication between the at least one transport tube of the first joint and the at least one transport tube of the second joint and/or sealably coupling the at least one jumper tube between the at least one transport tube of the first joint and the at least one transport tube of the second joint.
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
Referring initially to
Platform 12 has a hoisting apparatus 26 and a derrick 28 for raising and lowering pipe strings such as work string 30.
A wellbore 32 extends through the various earth strata including formation 14. A casing 34 is secured within wellbore 32 by cement 36. Work string 30 includes various tools including joints 38, 40, 42 that form the gravel packing apparatus of the present invention that is positioned in an interval of wellbore 32 adjacent to formation 14 between packers 44, 46. When it is desired to gravel pack annular region 48 surrounding joints 38, 40, 42, a fluid slurry including a liquid carrier and a particulate material such as sand, gravel or proppants is pumped down work string 30.
Some or all of the fluid slurry is typically injected directly into annular region 48 in a known manner, such as through a crossover tool (not pictured), which allows the slurry to travel from the interior of work string 30 to the exterior of work string 30. Once the fluid slurry is in annular region 48, a portion of the gravel in the fluid slurry is deposited in annular region 48. Some of the liquid carrier may enter formation 14 through perforation 50 while the remainder of the fluid carrier along with some of the gravel enters certain sections of joints 38, 40, 42 filling those sections with gravel. The sand control screens within joints 38, 40, 42 disallows further migration of the gravel but allows the liquid carrier to travel therethrough into work string 30 and up to the surface via annulus 52. If sand bridges form in annular region 48, some or all of the fluid slurry is injected or diverted into the slurry delivery subassemblies within joints 38, 40, 42 to bypass the sand bridge such that a complete pack can be achieved.
Even though
Referring next to
Positioned around base pipe 108 is a filter medium depicted as a fluid-porous, particulate restricting wire mesh screen 112. Screen 112 is designed to allow fluid flow therethrough but prevent the flow of particulate materials of a predetermined size from passing therethrough. Screen 112 preferably has a plurality of layers of wire mesh including one or more drainage layers and one or more filter layers wherein the drainage layers that have a mesh size that is larger than the mesh size of the filter layers. For example, a drainage layer may preferably be positioned as the outermost layer and the innermost layer of wire mesh screen 112 with the filter layer or layers positioned therebetween. Positioned around screen 112 is a screen wrapper 114 that has a plurality of openings 116 which allow the flow of production fluids therethrough. The exact number, size and shape of openings 116 is not critical to the present invention, so long as sufficient area is provided for fluid production and the integrity of screen wrapper 114 is maintained. Typically, various sections of screen 112 and screen wrapper 114 are manufactured together as a unit by, for example, diffusion bonding or sintering the layers of wire mesh that form screen 112 together with screen wrapper 114, then rolling the unit into a tubular configuration. The two ends of the tubular unit are then seam welded together. Several tubular units of the screen and screen wrapper combination may be placed over each joint of base pipe 108 and secured thereto by welding or other suitable technique. It should be understood by those skilled in the art that even though
Disposed between outer tubular 102 and sand control screen assembly 106 is a slurry delivery subassembly 118. In the illustrated embodiment, slurry delivery subassembly 118 includes a pair of transport tubes 120, 122, a pair of packing tubes 124, 126 and a manifold 128 that provides fluid communication between transport tubes 120, 122 and packing tubes 124, 126. As illustrated, transport tubes 120, 122 extend longitudinally past outer tubular 102 such that the transport tubes 120, 122 of one joint can be fluidically coupled to the transport tubes 120, 122 of another joint as explained in greater detail below. Packing tubes 124, 126 each include a plurality of nozzles, such as nozzle 130 of packing tube 124 and nozzle 132 of packing tube 126. In the event of sand bridge formation or as part of a planned gravel packing process, some or all of the fluid slurry is injected into the slurry delivery subassembly 118 of the uppermost joint. The fluid slurry is able to travel from one joint to the next via the transport tubes 120, 122. As the fluid slurry travels from joint to joint, portions of the fluid slurry enter packing tubes 124, 126 via manifold 128. From packing tubes 124, 126, the fluid slurry is able to enter the annular region surrounding gravel packing apparatus 100 by exiting slurry delivery subassembly 118 via nozzles 130, 132. In this manner, a complete gravel pack may be achieved even if sand bridges form in the annular region surrounding gravel packing apparatus 100.
As best seen in
Referring now to
It should be understood by those skilled in the art that even though transport tubes 120, 122 are depicted as being received and supported in outer slots 212, 214 of ring assembly 210, transport tubes may cooperate with a ring assembly in alternate ways, including, but not limited to, extending through openings in a ring assembly, extending only partially into openings of a ring assembly or otherwise being fluidically coupled to one side of a ring assembly wherein the openings of the ring assembly become part of a fluid path for the fluid slurry. In such an embodiment, the jumper tubes that fluidically couple the transport tubes of one joint with the transport tubes of the adjacent joint are similarly partially inserted into the openings of the ring assembly or otherwise fluidically coupled to the other side of the ring assembly.
As best seen in
It should be understood by those skilled in the art that even though
In
The operation of assembling the gravel packing apparatus of the present invention will now be described with reference to
In this manner, the rotatably mounted slurry delivery subassemblies of the present invention enable assembly of the gravel packing apparatus of the present invention on the rig floor using a simple and efficient procedure.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
Number | Date | Country | Kind |
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PCT/US2012/061201 | Oct 2012 | US | national |