RIG STORAGE SYSTEM

BACKGROUND

1. Field

Embodiments disclosed herein relate generally to a vessel used for storing and transporting materials on a drilling rig. More specifically, embodiments disclosed herein relate to use of a vessel for cuttings storage and/or transport.

2. Background Art

In the drilling of wells, a drill bit is used to dig many thousands of feet into the earth's crust. Oil rigs typically employ a derrick that extends above the well drilling platform or deck. The derrick supports joint after joint of drill pipe connected end-to-end during the drilling operation. As the drill bit is pushed further into the earth, additional pipe joints are added to the ever lengthening “string” or “drill string”. Therefore, the drill string typically includes a plurality of joints of pipe.

Fluid “drilling mud” is pumped from the well drilling platform, through the drill string, and to a drill bit supported at the lower or distal end of the drill string. The drilling mud lubricates the drill bit and carries away well cuttings generated by the drill bit as it digs deeper. The cuttings are carried in a return flow stream of drilling mud through the well annulus and back to the well drilling platform at the earth's surface. When the drilling mud reaches the platform, it is contaminated with small pieces of shale and rock that are known in the industry as well cuttings or drill cuttings. Once the drill cuttings, drilling mud, and other waste reach the platform, a “shale shaker” is typically used to remove the drilling mud from the drill cuttings so that the drilling mud may be reused. The remaining drill cuttings, waste, and residual drilling mud are then transferred to a holding trough or vessel for disposal. The drill cuttings are typically stored in large tanks or vessels on the drilling rig platform. These vessels may be large in size, and therefore, may require large spaces on the drilling rig. In some situations, for example with specific types of drilling mud, the drilling mud may not be reused and it must also be disposed. Typically, the non-recycled drilling mud is disposed of separate from the drill cuttings and other waste by transporting the drilling mud via a vessel to a disposal site.

The disposal of the drill cuttings and drilling mud is a complex environmental problem. Drill cuttings contain not only the residual drilling mud product that would contaminate the surrounding environment, but may also contain oil and other waste that is particularly hazardous to the environment, especially when drilling in a marine environment.

In the Gulf of Mexico, for example, there are hundreds of drilling platforms that drill for oil and gas by drilling into the subsea floor. These drilling platforms may be used in places where the depth of the water may be many hundreds of feet. In such a marine environment, the water is typically filled with marine life that cannot tolerate the disposal of drill cuttings and other waste. Therefore, there is a need for a simple, yet workable solution to the problem of disposing of well drill cuttings, drilling mud, and/or other waste in offshore marine and other fragile environments.

Traditional methods of disposal include dumping, bucket transport, cumbersome conveyor belts, screw conveyors, and washing techniques that require large amounts of water. Adding water creates additional problems such as added volume, bulk, and transportation. Installing conveyors requires major modification to the rig area and involves extensive installation hours and expense.

Another method of disposal includes returning the drill cuttings, drilling mud, and/or other waste via injection under high pressure into an earth formation. Generally, the injection process involves preparation of a slurry within surface-based equipment and pumping the slurry into a well that extends relatively deep underground into a receiving stratum or adequate formation. Material to be injected back into a formation may be prepared into a slurry acceptable to high pressure pumps used in pumping material down a well. The particles are usually not uniform in size and density, thus making the slurrification process complex. If the slurry is not the correct density, the slurry often plugs circulating pumps. The abrasiveness of the material particles may also abrade or damage the pump impellers causing cracking. Some centrifugal pumps may be used for grinding the injection particles by purposely causing pump cavitations.

The basic steps in the injection process include the identification of an appropriate stratum or formation for the injection; preparing an appropriate injection well; formulation of the slurry, which includes considering such factors as weight, solids content, pH, gels, etc.; performing the injection operations, which includes determining and monitoring pump rates such as volume per unit time and pressure; and capping the well.

In some instances, the cuttings, which are still contaminated with some oil, are transported from a drilling rig to an offshore rig or ashore in the form of a thick heavy paste for injection into an earth formation. Typically, the material is transferred into special skips of about 10 ton capacity which are loaded by crane from the rig onto supply boats. This is a difficult and dangerous operation that may be laborious and expensive.

U.S. Pat. No. 6,179,071 discloses that drill cuttings may be stored in a holding tank or multiple tanks on a drilling rig. The holding tank is then connected to a floating work boat with a discharge flow line. Cuttings may then be transferred to the boat via the flow line.

U.S. Pat. No. 6,709,216, and related patent family members, disclose that cuttings may also be conveyed to and stored in an enclosed, transportable vessel, where the vessel may then be transported to a destination, and the drill cuttings may be withdrawn therefrom. The transportable storage vessel has one or several lower conical sections structured to achieve mass flow of the material in the vessel, and withdrawal of the cuttings may include applying a compressed gas to the cuttings in the vessel. The transportable vessels are designed to fit within a 20 foot ISO (International Organization for Standardization) container frame. These conical vessels will be referred to herein as ISO-vessels. This patent is herein incorporated by reference in its entirety.

As described in U.S. Pat. No. 6,709,216 and family, the ISO-vessels may be lifted onto a drilling rig by a rig crane and used to store cuttings. The vessels may then be used to transfer the cuttings onto a supply boat. The vessels may also serve as buffer storage while a supply boat is not present. Alternatively, the storage vessels may be lifted off the rig by cranes and transported by a supply boat.

Space on offshore platforms is limited. In addition to the storage and transfer of cuttings, many additional operations take place on a drilling rig, including tank cleaning, slurrification operations, drilling, chemical treatment operations, raw material storage, mud preparation, mud recycle, mud separations, and many others.

Due to the limited space, it is common to modularize these operations and to swap out modules when not needed or when space is needed for the equipment. For example, cuttings containers may be offloaded from the rig to make room for modularized equipment used for tank cleaning operations. Modularized tank cleaning operations may include a water recycling unit of an automatic tank cleaning system, such as described in U.S. Patent Application Publication No. 20050205477, assigned to the assignee of the present disclosure and hereby fully incorporated by reference.

In other drilling operations, cuttings containers may be offloaded from the rig to make room for environmental and/or drilling fluid recycling systems. Such systems may include a number of mixing, flocculating, and storage tanks to clean industrial wastewater produced during drilling or shipping operations. Examples of such environmental and drilling fluid recycling methods and systems are disclosed in U.S. Pat. Nos. 6,881,349 and 6,977,048, assigned to the assignee of the present disclosure, and hereby incorporated in their entirety.

Slurrification systems that may be moved onto a rig are typically large modules that are fully self-contained, receiving cuttings from a drilling rig's fluid/mud recovery system. For example, PCT Publication No. WO 99/04134 discloses a process module containing a first slurry tank, grinding pumps, a shale shaker, a second slurry tank, and an optional holding tank. The module may be lifted by a crane on to an offshore drilling platform.

The lifting operations required to swap modular systems, as mentioned above, may be difficult, dangerous, and expensive. Additionally, many of these modularized operations are self-contained, and therefore include redundant equipment, such as pumps, valves, and tanks or storage vessels.

There exists a need for more efficient use of deck space and equipment. Additionally, there exists a need to minimize the number or size of lifts to or from a rig. Accordingly, there is a continuing need for systems and methods for efficiently storing and transporting materials, including free flowing materials and non-free flowing materials.

SUMMARY OF INVENTION

In one aspect, embodiments disclosed herein relate to a system for storing cuttings including a drilling rig having a deck and at least two support structures, and a least one cuttings storage vessel disposed in at least one of the at least two support structures.

In another aspect, embodiments disclosed herein relate to a system for storing cuttings including a drilling rig having a deck and at least two support structures, and at least one pressurized vessel disposed in at least one of the at least two support structures, wherein the at least one pressurized vessel is configured to store a material.

In another aspect, embodiments disclosed herein relate to a method of storing cuttings on a drilling rig including transferring materials from a deck of the drilling rig to a pressurized vessel disposed in a support structure of the drilling rig.

In another aspect, embodiments disclosed herein relate to a method of preparing a drilling rig for cuttings storage including disposing at least one cuttings storage vessel in at least one support structure of the drilling rig.

Other aspects and advantages of the invention will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a front view of a drilling rig in accordance with embodiments disclosed herein.

FIG. 1B is a cross-sectional view of a support structure of a drilling rig in accordance with embodiments disclosed herein.

FIG. 1C is a perspective view of a storage vessel in accordance with embodiments disclosed herein.

FIG. 1D is a partial perspective view of a storage vessel in accordance with embodiments disclosed herein.

FIG. 2 shows a top view of a system for transferring material from an off-shore rig in accordance with an embodiment of the present disclosure.

FIG. 3 is a side view of a system illustrating use of cuttings storage vessels in a cuttings storage/transfer system and in a module-based system fluidly connected to the cuttings storage vessels in accordance with an embodiment of the present disclosure.

FIG. 4 shows a slurrification system in accordance with embodiments of the present disclosure.

FIG. 5 shows a grinding device in accordance with embodiments of the present disclosure.

FIG. 6 shows a slurrification system in accordance with embodiments of the present disclosure.

FIG. 7 shows a slurrification system in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

In one aspect, embodiments disclosed herein relate to systems and methods for storing and transporting non-free flowing materials, including drill cuttings, and free flowing materials. Drilling locations may include both on-shore and off-shore drill sites, such as drilling rigs, platforms, drill-ships, drilling barges, and the like. In other aspects, embodiments relate to using pressurized vessels for storage and transportation combined with drill cuttings slurrification, cuttings processing (mechanical and thermal drying), tank cleaning, and fluid processing systems.

FIG. 1A shows a drilling rig 1000 in accordance with embodiments disclosed herein. In particular, drilling rig 1000 includes a system 1002 for storing and transporting non-free flowing and/or free flowing materials. As used herein, non-free flowing materials refer to materials that do not readily flow from a container, for example, cuttings, powders, and dry materials. As used herein, free flowing materials refer to materials that may readily flow from a container, for example, proppants, chemicals, and liquids. In some embodiments a mixture of non-free flowing and free-flowing materials, for example, a slurry, may be stored in the system 1002 of drilling rig 1000.

As shown in FIG. 1A, the system 1002 for storing and transporting non-free flowing materials and/or free flowing material in accordance with embodiments disclosed herein includes at least one storage vessel 1004 disposed in at least one support structure 1006 of drilling rig 1000. Drilling rig 1000 may be an offshore drilling rig having a deck 1005 supported by at least two support structures 1006, or legs. The at least one support structure 1006 is coupled to at least one buoyant device 1008, for example, a pontoon. One of ordinary skill in the art will appreciate that any number of support structures 1006 or buoyant devices 1008 may be used without departing from the scope of embodiments disclosed herein. For example, in one embodiment, drilling rig 1000 may include three or four support structures supported by one or more buoyant devices 1008.

In one embodiment, at least one storage vessel 1004 may be constructed or installed in at least one support structure 1006 during fabrication or manufacture of the at least one support structure 1006. Alternatively, a support structure 1006 of a drilling rig 1000 may be retrofitted to include at least one storage vessel 1004. For example, in one embodiment, a hole may be cut in at least one support structure 1006, using any method known in the art. At least one storage vessel 1004 may be secured in the support structure 1006 and the cut section from the support structure 1006 may be sealed and welded back into place on the support structure 1006. In one embodiment, the at least one storage vessel 1004 may be fixedly attached within at least one support structure 1006. As used herein, fixedly attached refers to a substantially permanent connection by, for example, integrally forming or welding. In alternate embodiments, the at least one storage vessel 1004 may be removably disposed in at least one support structure 1006. For example, storage vessel 1004 may be bolted, locked, or screwed into place within the at least one support structure 1006.

In one embodiment, at least one storage vessel 1004 may be disposed in at least one support structure 1006 above sea level. In accordance with certain embodiments, at least one storage vessel 1004 may be disposed in at least one support structure 1006 proximate sea level. Typically, a drilling rig deck 1005 may be disposed approximately 65 to 100 feet (20-30 m) above sea level. Thus, in some embodiments, the at least one storage vessel 1004 may be disposed in at least one support structure 1006 less than 15 ft. above sea level. In another embodiment, the at least one storage vessel 1004 may be disposed in at least one support structure 1006 less than 30 ft. above sea level. In yet other embodiments, the at least one storage vessel 1004 may be disposed in at least one support structure 1006 less than 50 ft. above sea level. One of ordinary skill in the art will appreciate that the location of the at least one storage vessel 1004 above sea level may vary depending on, for example, the particular drilling rig 1000 being used, drilling equipment used, or manufacturing limitations, without departing from the scope of the embodiments disclosed herein.

As described above, in certain embodiments, only one support structure 1006 may contain at least one storage vessel 1004 storing a material therein. Additionally, in certain embodiments, more than one support structure 1006 may contain at least one storage vessel 1004, but only one or less than all of the storage vessels 1004 may contain a material. In such embodiments, the stored material may add additional weight to a given side or area of drilling rig 1000. However, fluid may be filled into at least one support structure 1006, as known in the art, to counteract or ballast any weight imbalances due to the distribution of stored material in the storage vessels 1004 disposed in at least one support structure 1006. Additionally, disposing the storage vessels 1004 proximate sea level, as discussed above, may also assist in stabilizing and/or reducing the effect of any imbalanced material weight distribution of drilling rig 1000.

As shown in FIG. 1B, in one embodiment, a plurality of storage vessels 1004a may be disposed in at least one support structure 1006a in a circular configuration. In such an embodiment, a staircase, conduit, or other equipment may be disposed in the space formed 1010 in the center of the circular configuration. Thus, the plurality of storage vessels 1004a may be arranged within the at least one support structure 1006a in a manner most convenient for the construction, modification, and use of support structure 1006a. For example, the plurality of storage vessels 1004a, disposed in the at least one support structure 1006a, may be arranged in a grouping towards the center of support structure, in a square configuration, opposite one another, or stacked on top of one another. Those of ordinary skill in the art will appreciate that the configuration of the plurality of storage vessels 1004a may vary without departing from the scope of embodiments disclosed herein.

Referring now to FIG. 1C, in some embodiments, the at least one storage vessel 1004 has an angled lower section 1012 structured to achieve mass flow of the material in the storage vessel 1004. In one embodiment, angled lower section 1012 includes one conical angle. These conical vessels may be referred to as ISO-vessels. Exemplary ISO-vessels is an ISO-pump® commercially available from M-I, LLC (Houston, Tex.). In alternate embodiments, as shown in FIG. 1D, the angled lower section 1012 of the at least one storage vessel 1004 has a plurality of angled structures 1014, forming, for example, a honeycomb structure, as disclosed in PCT Publication WO 2007/034215 A1, incorporated by reference herein.

Referring generally to FIG. 1A, in one embodiment, material stored in at least one storage vessel 1004 disposed in at least one support structure 1006 may be transferred or conveyed to an offsite location. In this embodiment, a least one discharge line 1016 may be operatively connected to an outlet (not shown) of storage vessel 1004. A distal end 1020 of discharge line 1016 may be operatively connected to a transport vessel (not shown) disposed on a transport vehicle (not shown), for example, a boat or barge. In some embodiments, as shown in FIG. 1B, material stored in a first storage vessel 1001a disposed in at least one support structure 1006a may be conveyed via conduit 1003 to a second storage vessel 1001b disposed in the same support structure 1006a.

To facilitate the transfer of material from a storage vessel 1004 to a transport vessel or between storage vessels 1004 (1001a, 1001b), in one embodiment, the at least one storage vessel 1004 may be pressurized. In such an embodiment, a pressurized storage vessel 1004 may store non-free flowing material, for example, cuttings. In this embodiment, a pneumatic transfer device (not shown) may be coupled to the at least one storage vessel 1004. Pneumatic transfer device may include, for example, a cuttings blower (not shown) and pneumatic transfer lines (now shown), such as disclosed in U.S. Pat. Nos. 6,698,989, 6,702,539, and 6,709,206, and hereby incorporated by reference herein. However, those of ordinary skill in the art will appreciate that other methods for transferring cuttings to storage vessels 1004 may include augers, conveyors, vacuum suction, and pneumatic blower systems.

Still referring to FIG. 1A, in one embodiment, the at least one storage vessel 1004 disposed in at least one support structure 1006 of drilling rig 1000 may store cuttings. In this embodiment, a pneumatic transfer device (not shown) may be operatively coupled to the at least one storage vessel. For example, a cuttings blower (not shown) may be disposed on the deck 1005 of drilling rig 1000 and configured to blow cuttings from, for example, a separatory device (not shown) disposed on the deck 1005, into at least one storage vessel 1004 disposed in the at least one support structure 1006. Thus, by placing the storage vessel 1004 in the at least one support structure 1006 of drilling rig 1000, more space may be made available for other equipment and/or operations on the deck 1005.

Cuttings stored in storage vessels 1004 in at least one support structure 1006 may be conveyed from the storage vessel 1004 to an offsite location. One or more discharge lines 1016 may be coupled to one or more storage vessels 1004 to provide for conveyance of the cuttings from storage vessel 1004 to a transport vehicle (not shown). In this embodiment, storage vessel 1004 may be pressurized and/or may be operatively coupled to a pneumatic transfer device to transfer the cuttings through an outlet of the storage vessel 1004. In one embodiment, cuttings may be transferred from the at least one storage vessel 1004 to a transport vessel (not shown) on a transport vehicle (not shown). In another embodiment, cuttings may be transferred from first storage vessel (1001a in FIG. 1B) to second storage vessel (1001b in FIG. 1B) via conduit (1003 in FIG. 1B).

In one embodiment, as shown in FIG. 2, two discrete streams of materials may be transferred contemporaneously (i.e., at least partially during the same time interval) to a transport vehicle, for example, a supply boat 5. In this embodiment, a first supply line 20 may transfer a first material from at least a first storage vessel 21 disposed in at least one support structure 1006 of drilling rig (not shown) to supply boat 5, and a second supply line 22 may transfer a second material from at least a second storage vessel 23 disposed in the at least one support structure 1006 to supply boat 5. The first and second materials may also be transferred to a cuttings storage assembly 25 disposed on supply boat 5. Alternatively, the first and second materials may be transferred to separate storage vessels; for example the first and/or second material may be transferred to a storage tank (not shown) disposed on or below the deck of supply boat 5.

In one embodiment, the first material may include dry cuttings, while the second material may include a fluid. One of ordinary skill in the art will appreciate that a fluid may include a liquid, slurry, or gelatinous material. Additionally, one of ordinary skill in the art will appreciate that dry cuttings may include cuttings processed by a separatory or cleaning system, like mechanical and/or thermal processing, such as Thermomechanical Cuttings Cleaner (TCC), commercially available from Thermtech (Bergen, Norway), and VERTI-G™ Dryer, commercially available from M-I LLC (Houston, Tex.). As such, cuttings may include small amounts of residual fluids, hydrocarbons, and/or other chemical additives used during the cleaning process. Pumps (not shown) may be coupled to the storage vessels 21, 23 to facilitate the transfer of material, including, for example, dry cuttings, a fluid, or a slurry, from a separatory or cleaning operation on the rig to supply boat 5. Alternatively, a pneumatic transfer system 26 may be coupled to the storage vessels 21, 23 to transfer materials, including dry cuttings, fluids, and slurries, to the supply boat 5. In one embodiment, the pneumatic transfer system 26 may include a forced flow pneumatic transfer system as disclosed in U.S. Pat. Nos. 6,698,989, 6,702,539, and 6,709,216. Providing contemporaneous transfer of discrete material streams (e.g., dry cuttings, fluids), may reduce the transportation time between a rig and a transport vehicle, such as, supply boat 5.

In one embodiment, cuttings storage assembly 25 may include at least one cuttings storage vessel 27. As such, the first material and the second material may be transferred to a single cuttings storage vessel 27 of cuttings storage assembly 25. In another embodiment, the first material and the second material may be transferred to separate cuttings storage vessels 27 of cuttings storage assembly 25. In one embodiment, a cutting storage vessel 27 disposed on the supply boat 5 may be used in a slurrification system, as disclosed below with reference to cuttings storage vessels disposed on a rig. In this embodiment, briefly, a module (not shown) may be operatively connected to the cuttings storage assembly 25 to incorporate existing cuttings storage vessels 27 into a slurrification system.

In contrast to the prior art methods, embodiments disclosed herein use storage vessels in two or more operations that are performed on a drilling rig. In one aspect, embodiments disclosed herein relate to operating a vessel in at least two operations performed on a rig. In some aspects, embodiments disclosed herein relate to using a vessel in both cuttings storage/transfer operations and a second operation. More specifically, embodiments disclosed herein relate to using a cuttings storage vessel as a cuttings storage/transfer vessel and as a component in a slurrification system, such as that disclosed in co-pending U.S. patent application Ser. No. 60/887,442, hereby incorporated by reference in its entirety.

Use of storage vessels and vessel assemblies in each of these additional systems will be described below. Additionally, modules that may integrate these vessels and vessel assemblies into more than one additional system will also be discussed. One of ordinary skill in the art will appreciate that storage vessels as described in embodiments disclosed herein may also be used in recycling systems, such as those disclosed in co-pending application Ser. No. 60/887,444, tank cleaning systems, such as those disclosed in co-pending application Ser. No. 60/887,509, in-transit slurrification systems, such as those disclosed in co-pending application Ser. No. 60/887,449, and cuttings processing systems, such as those disclosed in co-pending application Ser. No. 60/887,514, all hereby incorporated by reference in their entireties.

Referring back to FIG. 1A, storage vessels 1004 disposed within at least one support structure 1006 of drilling rig 1000 may be used in other systems/operations typically performed on the deck 1005. For example, storage vessels 1004 may be used in a slurrification system as described in further detail below. In this embodiment, cuttings disposed in at least one storage vessel 1004 may be combined with a fluid provided by a fluid supply line (not shown) in fluid communication with the at least one storage vessel 1004.

Referring now to FIG. 3, a rig 40, including a system module 42 according to embodiments of the present disclosure, is shown. System module 42 may be located anywhere on rig 40, and in some embodiments is located proximate at least one cuttings storage vessel 43, or a vessel assembly, disposed in at least one support structure 41, that may be fluidly connected to system module 42 via connection lines 44. Cuttings storage vessels 43 may be detachably connected to a second set of storage vessels 45 located on a supply boat 46 by a flexible hose 47. System module 42 may include a slurrification system module.

In operation, cuttings may be transferred to cuttings storage vessels 43 via one or more pneumatic transfer devices 48 located on rig 40. The cuttings may be stored in cuttings storage vessels 43 until they are transferred to supply boat 46 for disposal thereafter.

Cuttings transfer systems and slurrification systems, as described above, are typically independent systems, where the systems may be located on rig 40 permanently or may be transferred to rig 40 from supply boat 46 when such operations are required. However, in embodiments disclosed herein, system module 42 may be located on rig 40 proximate cuttings storage vessels 43, and transfer lines 44 may be connected therebetween to enable use of the cuttings storage vessels 43 with tanks, pumps, grinding pumps, chemical addition devices, cleaning equipment, water supply tanks, filter systems, and other components that may be used in other operations performed at a drilling location, including slurrification of drill cuttings. Such integrated systems may allow for existing single use structures (e.g., cuttings storage vessels 43) to be used in multiple operations (e.g., slurrification systems and cuttings storage/transfer). Thus, when not being used to store or transport cuttings, vessels 43 may be operated in a tank a slurrification system.

Integration of a cuttings storage vessel into a slurrification system is now described with respect to cuttings storage vessel(s) disposed in at least one support structure of a drilling rig. In this embodiment a module may be disposed at the work site proximate the cuttings storage vessel and operatively connected to the cuttings storage vessel, thereby converting the cuttings storage vessel from a vessel for storing cuttings to a component of a slurrification system.

As described above, previous fluid slurrification systems required the conversion of valuable drilling rig space for storing independent fluid recovery vessels and processing equipment. However, embodiments disclosed herein allow existing structural elements (i.e., cuttings storage vessels) to be used in multiple operations. Modules in accordance with embodiments disclosed herein are relatively small compared to previous systems, thereby preserving valuable drill space, and preventing the need for costly and dangerous lifting operations.

Referring now to FIG. 4, a slurrification system 300 incorporating a first cuttings storage vessel 302 is illustrated. Slurrification system 300 includes a module 352, or drive unit, configured to operatively connect with the first cuttings storage vessel 302 disposed in at least one support structure (not shown) of a drilling rig (not shown), and a fluid supply line 378. Module 352 may include a containment unit, a skid, a housing, or a moveable platform configured to house select slurrification system components, as described in more detail below.

In this embodiment, system 300 includes an independent power source 360 for providing power to components of module 352. Power source 360 is electrically connected to, for example, grinding device 354 and/or a programmable logic controller (PLC) 361. Those of ordinary skill in the art will appreciate that such a power source may provide primary or auxiliary power for powering components of module 352. In other embodiments, power source 360 may be merely an electrical conduit for connecting a power source on a rig (not shown) via an electrical cable 362, to module 352.

Module 352 includes an inlet connection 370 configured to connect with outlet 372 of first cuttings storage vessel 302, and an outlet connection 374 configured to connect with an inlet 376 of first cuttings storage vessel 302. Inlet connection 370 may be connected to outlet 372 and outlet connection 374 may be connected to inlet 376 by fluid transfer lines, for example, flexible hoses and/or new or existing piping. Module 352 further includes a grinding device 354 configured to facilitate the transfer of fluids from the first cuttings storage vessel 302, through the module 352, and back to the first cuttings storage vessel 302. Grinding device 354 is configured to reduce the particle size of solid materials of the drill cuttings transferred therethrough.

In one embodiment, grinding device 354 may include a grinding pump. The grinding pump may be, for example, a centrifugal pump, as disclosed in U.S. Pat. No. 5,129,469, and incorporated by reference herein. As shown in FIG. 5, a centrifugal pump 458, configured to grind or reduce the particle size of drill cuttings, may have a generally cylindrical casing 480 with an interior impeller space 482 formed therein. Centrifugal pump 458 may include an impeller 484 with backward swept blades with an open face on both sides, that is, the blades or vanes 485 are swept backward with respect to a direction of rotation of the impeller and are not provided with opposed side plates forming a closed channel between the impeller fluid inlet area 487 and the blade tips. The casing 480 has a tangential discharge passage 488 formed by a casing portion 490. The concentric casing of centrifugal pump 458 and the configuration of the impeller blades 485 provide a shearing action that reduces the particle size of drill cuttings. The blades 485 of the impeller 484 may be coated with a material, for example, tungsten carbide, to reduce wear of the blades 485. One of ordinary skill in the art will appreciate that any grinding pump known in the art for reducing the size of solids in a slurry may be used without departing from the scope of embodiments disclosed herein.

In an alternative embodiment, as shown in FIG. 6, grinding device 554 may include a pump 556 and a grinder 557, for example, a ball mill. In this embodiment, cuttings may be injected into the grinder 557, wherein the particle size of the solids is reduced. The pump 556 may then pump the slurry back to first cuttings vessel 502. In one embodiment, the pump may include a grinding pump, as disclosed above, as a second grinder, for further reduction of the particle size of solids exiting the grinder 557.

Referring back to FIG. 4, in one embodiment, slurrification system 300 further includes a second cuttings storage vessel 390 disposed in the support structure (not shown) of the drilling rig (not shown). Second cuttings storage vessel 390 may be configured to supply cuttings to first cuttings storage vessel 302. In one embodiment, a pump (not shown), as known in the art, may be used to transfer the cuttings. In another embodiment, a pneumatic transfer device (not shown), as disclosed above, may be used to transfer the cuttings to the first cuttings storage vessel 302. One of ordinary skill in the art will appreciate that any method for transferring the cuttings to first storage vessel 302 may be used without departing from the scope of embodiments disclosed herein.

In one embodiment, module 352 may further include a pneumatic control device (not shown) to control the flowrate of air injected into the cuttings storage vessel 302 by a pneumatic transfer device (not shown). In such an embodiment, an air line (not shown) from an air compressor (not shown) may be coupled to the pneumatic control device (not shown) in module 352 to control a flow of air into first cuttings storage vessel 302.

In another embodiment, cuttings may be supplied to first cuttings storage vessel 302 from a classifying shaker (not shown) or other cuttings separation or cleaning systems disposed on the drilling rig. Additionally, multiple cuttings storage vessels disposed in the support structure of the drilling rig may be connected to and supply cuttings to first cuttings storage vessel 302. In one embodiment, each cuttings storage vessel may be configured to supply cuttings of predetermined sizes, for example, coarse cuttings or fines. Cuttings of a selected size may then be provided to first cuttings storage vessel 302 to form a slurry of a predetermined density. One of ordinary skill in the art will appreciate that the cuttings may be transferred to the first cuttings storage vessel 302 by any means known in the art, for example, by a pump or a pneumatic transfer device, as described above.

During operation of slurrification system 300, fluid supply line 378 may be configured to supply a fluid to first cuttings storage vessel 302. One of ordinary skill in the art will appreciate that the fluid supply line 378 may supply water, sea water, a brine solution, chemical additives, or other fluids known in the art for preparing a slurry of drill cuttings. As the fluid is pumped into first cuttings storage vessel 302, cuttings from the second cuttings storage vessel 390, or other components of the rig's cuttings separation system, as described above, may be transferred into first cuttings storage vessel 302.

As first cuttings storage vessel 302 fills with fluid and cuttings, the mixture of fluid and cuttings is transferred to module 352 through the inlet connection 370 of the module 352. In one embodiment, the mixture may be transferred by a pneumatic transfer device, a vacuum system, a pump, or any other means known in the art. In one embodiment, the pneumatic transfer device may include a forced flow pneumatic transfer system. The mixture of fluid and cuttings is pumped through grinding device 354, wherein the cuttings are reduced in size. The mixture, or slurry, is then pumped back down to first cuttings storage vessel 302 via outlet connection 374. The slurry may cycle back through module 352 one or more times as needed to produce a slurry of a predetermined density or concentration of cuttings as required for the particular application or re-injection formation.

Referring now to FIG. 7, in one embodiment, module 652 further includes a valve 694 disposed downstream of grinding device 654, wherein valve 694 is configured to redirect the flow of the slurry exiting the grinding device 654. In one embodiment, a PLC 661 may be operatively coupled to module 652 and configured to close or open the valve 694, thereby redirecting the flow of the slurry. In one embodiment, the PLC 695 may control the valve 694 to move after a pre-determined amount of time of fluid transfer through module 652. In another embodiment, a sensor (not shown) may be operatively coupled to the valve 694 to open or close the valve when a pre-determined condition of the slurry is met. For example, in one embodiment, a density sensor (not shown) may be coupled to valve 694, such that, when the density of the slurry exiting grinding device 654 reaches a pre-determined value, valve 694 moves, i.e., opens or closes, and redirects the flow of the slurry from the first cuttings storage vessel 302 to another cuttings storage vessel, a slurry tank, a skip, or injection pump for injection into a formation.

In another embodiment, a conductivity sensor (not shown) may be coupled to valve 694, such that, when the density of the slurry exiting grinding device 654 reaches a pre-determined value, valve 694 moves and redirects the flow of the slurry from the first cuttings storage vessel 302 to another cuttings storage vessel, a slurry tank, a skip, or injection pump for injection into a formation. One of ordinary skill in the art will appreciate that other apparatus and methods may be used to redirect the flow of the slurry once a predetermined concentration of cuttings in suspension, density, or conductivity has been met. Commonly, a slurry with a concentration of up to 20% cuttings in suspension is used for re-injection into a formation. However, those of ordinary skill in the art will appreciate that direct injection of slurry, using embodiments of the present disclosure, may provide for an increased concentration of cuttings in the slurry.

A slurry formed by a slurrification system, as described above, may be transferred to another cuttings storage vessel, a slurry tank, a skip, or directly injected into a formation. Slurry that is transferred to a tank, vessel, skip, or other storage device, may be transferred off-site to another work site. In one embodiment, the storage device may be lifted off of a rig by a crane and transferred to a boat. Alternatively, slurry may be transferred via a hose, tubing, or other conduit, from the storage vessel dispose in the at least one leg of the drilling rig to a slurry tank disposed on the boat.

In one embodiment, the slurry may be transported from one work site to another work site for re-injection. For example, the slurry may be transported from an offshore rig to another offshore rig. Additionally, the slurry may be transported from an offshore rig to an on-land work site. Further the slurry may be transported from an on-land work site to an offshore work site.

Those of ordinary skill in the art will appreciate that the components of systems 300, 500, and 600 may be interchanged, interconnected, and otherwise assembled in a slurrification system. As such, to address the specific requirements of a drilling operation, in particular, for cuttings re-injection, the components of the systems and modules disclosed herein may provide for an interchangeable and adaptable system for slurrification at a drilling location.

Advantageously, embodiments disclosed herein may provide a materials storage and transport system that reduces the amount of required space on a drilling rig. In another aspect, embodiments disclosed herein may provide a method of transferring stored materials to an offsite location. In yet another aspect, embodiments disclosed herein may provide a storage and transport system for cuttings that reduces the amount of required space on a drilling rig.

Furthermore, embodiments disclosed herein may advantageously provide a slurrification system that reduces the amount of required space at a work site to operate the slurrification system. In another aspect, embodiments disclosed herein may provide a slurrification system that reduces the amount of equipment or number of components required to prepare slurries for re-injection into a formation. In yet another aspect, embodiments disclosed herein may provide a safer slurrification system by reducing the number of crane lifts required to install the system.

Advantageously, embodiments disclosed herein may also provide for systems and methods that more efficiently store and transport non-free flowing and free flowing materials on a drilling rig. Because offshore platform space is often limited, and crane operations to transfer large storage tanks or containers are often expensive and dangerous, embodiments of the present disclosure may decrease the cost of drilling operations by decreasing the number of crane lifts.

While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

RIG STORAGE SYSTEM

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

US Classifications

International Classifications

Abstract

Description

Claims

PCT Information

Provisional Applications (1)