weatherford mp 10 mud pump free sample

2023-05-21 21:22:12

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

Weatherford products and services are subject to the Company’s standard terms and conditions, available on request or at weatherford.com. For more information contact an authorized Weatherford representative. Unless noted

otherwise, trademarks and service marks herein are the property of Weatherford and may be registered in the United States and/or other countries. Weatherford products named herein may be protected by one or more U.S. and/or

foreign patents. For more information, contact patents@weatherford.com. Specifications are subject to change without notice. Weatherford sells its products and services in accordance with the terms and conditions set forth in the

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

The Weatherford MP Series F & FB style design compatibility means that parts are readily available and fully interchangeable. The MP series mud pumps are based on the industry-recognized, proven and trusted F & FB style mud pump. The MP10 & MP16 Models are always in stock and available for immediate shipment.

The MP Series F style design compatibility means that parts are readily available and fully interchangeable. The MP series mud pumps are based on the industry-recognized, proven and trusted F style mud pump. Any of these parts for the MP Series models below can be purchased from Rig Manufacturing, LLC.

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

The Computer-Aided Design ("CAD") files and all associated content posted to this website are created, uploaded, managed and owned by third-party users. Each CAD and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or real-world item, product, or good it may purport to portray.

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

A wide variety of weatherford mud pump options are available to you, such as 1 year, not available.You can also choose from new, weatherford mud pump,As well as from energy & mining, construction works , and machinery repair shops. and whether weatherford mud pump is 1.5 years, 6 months, or unavailable.

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

This 3D model is a copy of triplex mud pump TPK 2200 from Aker / Wirth.3D model is made for visualization purpose only so it may differ from the real TPK 2200 and some internal components are missing.* Available in STEP format.* Some more renders...

This mud pump is reverse engineered for manufacturing . most of parts are 3d modeled using Solidworks and some parts are 3d scannned and then converted to 3d models. ...This design is a DFM (design for manufacturing) and it is manufactured.

This mud pump is reverse engineered for manufacturing . most of parts are 3d modeled using Solidworks and some parts are 3d scannned and then converted to 3d models. This design is a DFM (design for manufacturing) and it is manufactured. ...

Continental Emsco F500 partial assembly for a drilling rig. ...Diesel engine C18, V-Belt transmission, centrifugal pump with AC motor. ...Still working on details and other accessories of the assembly.C18 ACERT is the only model I have at the moment.

Models used: - High pressure mud pump made by me; - lego man by zethafary ; - One more adjustable wrench by Andrew Smolkov ; - Pencil by Kevin Stapleton ; - Marker by Davit ; Photoshop was used only for combining various KeyShot renders together.

The file contains model Mud Pumps made in surface-modeling and low-poly for game engines. ...There is a tiling texture and a texture with an inscription.

... for oil drilling. ...The primary purpose of a mud pump is to circulate the mud, also called drilling fluid, during drilling operations. ... Quintuplex gets its name because it has five plungers that force the drilling fluid into the drill string. ...

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

This is a basic mud pump used on a common drill site as part of the mud system, the model itself is pretty basic, 1 piece and no materials. looks great on a drill site animation!

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

All CategoriesAir compressors (2)Air compressor (1)Screw air (1)Attachments (2)Bucket (1)Screen (1)Backhoes (1)Excavators (1)Compactors (2)Compactor (1)Roller (1)Drill Rigs (1)Drilling (18)Brakes (1)Cat walk (1)Drilling Rig (1)Equipment (5)Mud Pits (3)Pipe wrangler (1)Pumps (3)Solids separation (3)Electrical Equipment (4)Circuit Breaker (1)Cutler Hammer (1)Eaton (1)Switchgear (1)Engines (24)Cores (2)Diesel (7)Drilling (2)Drilling Rig (1)Engine (5)Equipment (2)Natural Gas (2)Oilfield (1)Pump drive (1)Pumps (1)Generators (18)Cat (3)Diesel (7)Generator (7)John Deere (1)Heaters (3)Air heater (1)Blower (1)Indirect fired heater (1)Iron (2)Pipe (1)Sucker Rod (1)Man Camps (3)Man Camp (2)Rig House (1)Mud Pumps (27)1000hp (4)Cat (1)Diesel (2)Drilling (1)Emsco (3)Engine (1)Equipment (1)Mud pump (7)Pump (7)Natural Gas Compression (10)Compressor Station (3)Engine (1)Frick (2)Natural Gas (3)Waukesha (1)Oil Field (5)Bathroom (1)Shipping container (1)Substructure (1)Support Equipment (1)Tanks (1)Production (3)Injection (1)Pump (1)Pumping Unit (1)Rigs (1)Swabbing Unit (1)Road Graders (3)Blade (1)Road Grader (1)Service Trucks (1)Service Truck (1)Silos (2)Sand silos (1)Tanks (1)Support Equipment (19)Accumulator (3)Cat walk (1)Closing Unit (2)Drilling Rig (2)HPU (1)Koomey (2)Kubota (1)Mud pump (1)Oilfield (1)Pipe handling (1)Pipe rack (1)Pipe wrangler (1)Power Swivel (1)Tanks (1)Telehandler (4)Cat (1)Forklift (1)Reachlift (1)Telehandler (1)Trailer (4)Flatbed (1)Gooseneck (1)Step deck (1)Trailer (1)Valves (82)

weatherford mp 10 mud <a href='https://www.ruidapetroleum.com/product/49'>pump</a> free sample

This application is a divisional of U.S. application Ser. No. 10/281,534, entitled “Internal Riser Rotating Control Head,” filed Oct. 28, 2002, which is a continuation-in-part of U.S. application Ser. No. 09/516,368, entitled “Internal Riser Rotating Control Head,” filed Mar. 1, 2000, which issued as U.S. Pat. No. 6,470,975 on Oct. 29, 2002, and which claims the benefit of and priority to U.S. Provisional Application Serial No. 60/122,530, filed Mar. 2, 1999, entitled “Concepts for the Application of Rotating Control Head Technology to Deepwater Drilling Operations,” all of which are hereby incorporated by reference in their entirety for all purposes.

An example of a marine riser and some of the associated drilling components, such as shown in FIG. 1, is proposed in U.S. Pat. No. 4,626,135, assigned on its face to the Hydril Company, which is incorporated herein by reference for all purposes. Since the riser R is fixedly connected between a floating structure or rig S and the wellhead W, as proposed in the "135 Hydril patent, a conventional slip or telescopic joint SJ, comprising an outer barrel OB and an inner barrel IB with a pressure seal therebetween, is used to compensate for the relative vertical movement or heave between the floating rig and the fixed riser. A diverter D has been connected between the top inner barrel IB of the slip joint SJ and the floating structure or rig S to control gas accumulations in the marine riser R or low pressure formation gas from venting to the rig floor F. A ball joint BJ above the diverter D compensates for other relative movement (horizontal and rotational) or pitch and roll of the floating structure S and the fixed riser R.

The diverter D can use a rigid diverter line DL extending radially outwardly from the side of the diverter housing to communicate drilling fluid or mud from the riser R to a choke manifold CM, shale shaker SS or other drilling fluid receiving device. Above the diverter D is the rigid flowline RF, shown in FIG. 1, configured to communicate with the mud pit MP. If the drilling fluid is open to atmospheric pressure at the bell-nipple in the rig floor F, the desired drilling fluid receiving device must be limited by an equal height or level on the structure S or, if desired, pumped by a pump to a higher level. While the shale shaker SS and mud pits MP are shown schematically in FIG. 1, if a bell-nipple were at the rig floor F level and the mud return system was under minimal operating pressure, these fluid receiving devices may have to be located at a level below the rig floor F for proper operation. Since the choke manifold CM and separator MB are used when the well is circulated under pressure, they do not need to be below the bell nipple.

As also shown in FIG. 1, a conventional flexible choke line CL has been configured to communicate with choke manifold CM. The drilling fluid then can flow from the choke manifold CM to a mud-gas buster or separator MB and a flare line (not shown). The drilling fluid can then be discharged to a shale shaker SS, and mud pits MP. In addition to a choke line CL and kill line KL, a booster line BL can be used.

In the past, when drilling in deepwater with a marine riser, the riser has not been pressurized by mechanical devices during normal operations. The only pressure induced by the rig operator and contained by the riser is that generated by the density of the drilling mud held in the riser (hydrostatic pressure). During some operations, gas can unintentionally enter the riser from the wellbore. If this happens, the gas will move up the riser and expand. As the gas expands, it will displace mud, and the riser will “unload.” This unloading process can be quite violent and can pose a significant fire risk when gas reaches the surface of the floating structure via the bell-nipple at the rig floor F. As discussed above, the riser diverter D, as shown in FIG. 1, is intended to convey this mud and gas away from the rig floor F when activated. However, diverters are not used during normal drilling operations and are generally only activated when indications of gas in the riser are observed. The "135 Hydril patent has proposed a gas handler annular blowout preventer GH, such as shown in FIG. 1, to be installed in the riser R below the riser slip joint SJ. Like the conventional diverter D, the gas handler annular blowout preventer GH is activated only when needed, but instead of simply providing a safe flow path for mud and gas away from the rig floor F, the gas handler annular blowout provider GH can be used to hold limited pressure on the riser R and control the riser unloading process. An auxiliary choke line ACL is used to circulate mud from the riser R via the gas handler annular blowout preventer GH to a choke manifold CM on the rig.

Recently, the advantages of using underbalanced drilling, particularly in mature geological deepwater environments, have become known. Deepwater is considered to be between 3,000 to 7,500 feet deep and ultra deepwater is considered to be 7,500 to 10,000 feet deep. Rotating control heads, such as disclosed in U.S. Pat. No. 5,662,181, have provided a dependable seal between a rotating pipe and the riser while drilling operations are being conducted. U.S. Pat. No. 6,138,774, entitled “Method and Apparatus for Drilling a Borehole into a Subsea Abnormal Pore Pressure Environment,” proposes the use of a rotating control head for overbalanced drilling of a borehole through subsea geological formations. That is, the fluid pressure inside of the borehole is maintained equal to or greater than the pore pressure in the surrounding geological formations using a fluid that is of insufficient density to generate a borehole pressure greater than the surrounding geological formation"s pore pressures without pressurization of the borehole fluid. U.S. Pat. No. 6,263,982 proposes an underbalanced drilling concept of using a rotating control head to seal a marine riser while drilling in the floor of an ocean using a rotatable pipe from a floating structure. U.S. Pat. Nos. 5,662,181; 6,138,774; and 6,263,982, which are assigned to the assignee of the present invention, are incorporated herein by reference for all purposes. Additionally, provisional application Serial No. 60/122,350, filed Mar. 2, 1999, entitled “Concepts for the Application of Rotating Control Head Technology to Deepwater Drilling Operations” is incorporated herein by reference for all purposes.

It has also been known in the past to use a dual density mud system to control formations exposed in the open borehole. See Feasibility Study of a Dual Density Mud System for Deepwater Drilling Operations by Clovis A. Lopes and Adam T. Bourgoyne, Jr., © 1997 Offshore Technology Conference. As a high density mud is circulated from the ocean floor back to the rig, gas is proposed in this May of 1997 paper to be injected into the mud column at or near the ocean floor to lower the mud density. However, hydrostatic control of abnormal formation pressure is proposed to be maintained by a weighted mud system that is not gas-cut below the seafloor. Such a dual density mud system is proposed to reduce drilling costs by reducing the number of casing strings required to drill the well and by reducing the diameter requirements of the marine riser and subsea blowout preventers. This dual density mud system is similar to a mud nitrification system, where nitrogen is used to lower mud density, in that formation fluid is not necessarily produced during the drilling process.

U.S. Pat. No. 4,813,495 proposes an alternative to the conventional drilling method and apparatus of FIG. 1 by using a subsea rotating control head in conjunction with a subsea pump that returns the drilling fluid to a drilling vessel. Since the drilling fluid is returned to the drilling vessel, a fluid with additives may economically be used for continuous drilling operations. ("495 patent, col. 6, ln. 15 to col. 7, ln. 24) Therefore, the "495 patent moves the base line for measuring pressure gradient from the sea surface to the mudline of the sea floor ("495 patent, col. 1, lns. 31-34). This change in positioning of the base line removes the weight of the drilling fluid or hydrostatic pressure contained in a conventional riser from the formation. This objective is achieved by taking the fluid or mud returns at the mudline and pumping them to the surface rather than requiring the mud returns to be forced upward through the riser by the downward pressure of the mud column ("495 patent, col. 1, lns. 35-40).

U.S. Pat. No. 4,836,289 proposes a method and apparatus for performing wire line operations in a well comprising a wire line lubricator assembly, which includes a centrally-bored tubular mandrel. A lower tubular extension is attached to the mandrel for extension into an annular blowout preventer. The annular blowout preventer is stated to remain open at all times during wire line operations, except for the testing of the lubricator assembly or upon encountering excessive well pressures. ("289 patent, col. 7, lns. 53-62) The lower end of the lower tubular extension is provided with an enlarged centralizing portion, the external diameter of which is greater than the external diameter of the lower tubular extension, but less than the internal diameter of the bore of the bell nipple flange member. The wireline operation system of the "289 patent does not teach, suggest or provide any motivation for use a rotating control head, much less teach, suggest, or provide any motivation for sealing an annular blowout preventer with the lower tubular extension while drilling.

Conventional rotating control head assemblies have been sealed with a subsea housing using active sealing mechanisms in the subsea housing. Additionally, conventional rotating control head assemblies, such as proposed by U.S. Pat. No. 6,230,824, assigned on its face to the Hydril Company, have used powered latching mechanisms in the subsea housing to position the rotating control head. A system and method that would eliminate the need for powered mechanisms in the subsea housing would be desirable because the subsea housing can remain bolted in place in the marine riser for many months, allowing moving parts in the subsea housing to corrode or be damaged.

Additionally, the use of a rotating control head assembly in a dual-density drilling operation can incur problems caused by excess pressure in either one of the two fluids. The ability to relieve excess pressure in either fluid would provide safety and environmental improvements. For example, if a return line to a subsea mud pump plugs while mud is being pumped into the borehole, an overpressure situation could cause a blowout of the borehole. Because dual-density drilling can involve varying pressure differentials, an adjustable overpressure relief technique has been desired.

In one embodiment, a pressure compensation assembly pressurizes lubricants in the bearing assembly at a predetermined pressure amount in excess of the higher of the subsea housing pressure above the seal or below the seal.

FIG. 1 is an elevation view of a prior art floating rig mud return system, shown in broken view, with the lower portion illustrating the conventional subsea blowout preventer stack attached to a wellhead and the upper portion illustrating the conventional floating rig, where a riser having a conventional blowout preventer is connected to the floating rig;

FIG. 26A is an elevation view of an upper section of a bearing assembly of a rotating control head according to one embodiment with an upper pressure compensation assembly;

Turning to FIG. 2, the riser or upper tubular R is shown positioned above a gas handler annular blowout preventer, generally designated as GH. While a “HYDRIL” GH 21-2000 gas handler BOP or a “HYDRIL” GL series annular blowout handler could be used, ram type blowout preventers, such as Cameron U BOP, Cameron UII BOP or a Cameron T blowout preventer, available from Cooper Cameron Corporation of Houston, Tex., could be used. Cooper Cameron Corporation also provides a Cameron DL annular BOP. The gas handler annular blowout preventer GH includes an upper head 10 and a lower body 12 with an outer body or first or subsea housing 14 therebetween. A piston 16 having a lower wall 16A moves relative to the first housing 14 between a sealed position, as shown in FIG. 2, and an open position, where the piston moves downwardly until the end 16A′ engages the shoulder 12A. In this open position, the annular packing unit or seal 18 is disengaged from the internal housing 20 of the present invention while the wall 16A blocks the gas handler discharge outlet 22. Preferably, the seal 18 has a height of 12 inches. While annular and ram type blowout preventers, with or without a gas handler discharge outlet, are disclosed, any seal to retractably seal about an internal housing to seal between a first housing and the internal housing is contemplated as covered by the present invention. The best type of retractable seal, with or without a gas handler outlet, will depend on the project and the equipment used in that project.

The internal housing 20 includes a continuous radially outwardly extending holding member 24 proximate to one end of the internal housing 20, as will be discussed below in detail. When the seal 18 is in the open position, it also provides clearance with the holding member 24. As best shown in FIGS. 8 and 9, the holding member 24 is preferably fluted with a plurality of bores or openings, like bore 24A, to reduce hydraulic surging and/or swabbing of the internal housing 20. The other end of the internal housing 20 preferably includes inwardly facing right-hand Acme threads 20A. As best shown in FIGS. 2, 3 and 10, the internal housing includes four equidistantly spaced lugs 26A, 26B, 26C, and 26D.

As best shown in FIGS. 2 and 7, the bearing assembly, generally designated 28, is similar to the Weatherford-Williams Model 7875 rotating control head, now available from Weatherford International, Inc. of Houston, Tex. Alternatively, Weatherford-Williams Models 7000, 7100, IP-1000, 7800, 8000/9000 and 9200 rotating control heads, now available from Weatherford International, Inc., could be used. Preferably, a rotating control head with two spaced-apart seals is used to provide redundant sealing. The major components of the bearing assembly 28 are described in U.S. Pat. No. 5,662,181, now owned by Weatherford/Lamb, Inc. The "181 patent is incorporated herein by reference for all purposes. Generally, the bearing assembly 28 includes a top rubber pot 30 that is sized to receive a top stripper rubber or inner member seal 32. Preferably, a bottom stripper rubber or inner member seal 34 is connected with the top seal 32 by the inner member 36 of the bearing assembly 28. The outer member 38 of the bearing assembly 28 is rotatably connected with the inner member 36, as best shown in FIG. 7, as will be discussed below in detail.

The outer member 38 includes four equidistantly spaced lugs. A typical lug 40A is shown in FIGS. 2, 7, and 10, and lug 40C is shown in FIGS. 2 and 10. Lug 40B is shown in FIG. 2. Lug 40D is shown in FIG. 10. As best shown in FIG. 7, the outer member 38 also includes outwardly-facing right-hand Acme threads 38A corresponding to the inwardly-facing right-hand Acme threads 20A of the internal housing 20 to provide a threaded connection between the bearing assembly 28 and the internal housing 20.

Returning again to FIGS. 2 and 7, first, a rotatable pipe P can be received through the bearing assembly 28 so that both inner member seals 32 and 34 sealably engage the bearing assembly 28 with the rotatable pipe P. Secondly, the annulus A between the first housing 14 and the riser R and the internal housing 20 is sealed using seal 18 of the annular blowout preventer GH. These two sealings provide a desired barrier or seal in the riser R both when the pipe P is at rest and while rotating. In particular, as shown in FIG. 2, seawater or a fluid of one density SW could be maintained above the seal 18 in the riser R, and mud M, pressurized or not, could be maintained below the seal 18.

Turning now to FIG. 5, a cylindrical internal housing 20′ could be used instead of the step-down internal housing 20 having a step down 20B to a reduced diameter 20C of 14″, as best shown in FIGS. 2 and 6. Both of these internal housings 20 and 20′ can be of different lengths and sizes to accommodate different blowout preventers selected or available for use. Preferably, the blowout preventer GH, as shown in FIG. 2, could be positioned in a predetermined elevation between the wellhead W and the rig floor F. In particular, it is contemplated that an optimized elevation of the blowout preventer could be calculated, so that the separation of the mud M, pressurized or not, from seawater or gas-cut mud SW would provide a desired initial hydrostatic pressure in the open borehole, such as the borehole B, shown in FIG. 4. This initial pressure could then be adjusted by pressurizing or gas-cutting the mud M.

Turning now to FIG. 7, a detail view of the seals and bearings for the Model 7875 Weatherford-Williams rotating control head, now sold by Weatherford International, Inc., of Houston, Tex., is shown. The inner member or barrel 36 is rotatably connected to the outer member or barrel 38 and preferably includes 9000 series tapered radial bearings 42A and 42B positioned between a top packing box 44A and a bottom packing box 44B. Bearing load screws, similar to screws 46A and 46B, are used to fasten the top plate 48A and bottom plate 48B, respectively, to the outer barrel 38. Top packing box 44A includes packing seals 44A′ and 44A″ and bottom packing box 44B includes packing seals 44B′ and 44B″ positioned adjacent respective wear sleeves 50A and 50B. A top retainer plate 52A and a bottom retainer plate 52B are provided between the respective bearing 42A and 42B and packing box 44A and 44B. Also, two thrust bearings 54 are provided between the radial bearings 42A and 42B.

In particular, the threadedly assembled internal housing 20 and the bearing assembly 28 could be run down the riser R on a standard drill collar or stabilizer (not shown) until the lugs 26A, 26B, 26C and 26D of the assembled internal housing 20 and bearing assembly 28 are blocked from further movement upon engagement with the shoulder R′ of riser R. The fixed preferably radially continuous holding member 24 at the lower end of the internal housing 20 would be sized relative to the blowout preventer so that the holding member 24 is positioned below the seal 18 of the blowout preventer. The annular or ram type blowout preventer, with or without a gas handler discharge outlet 22, would then be moved to the sealed position around the internal housing 20 so that a seal is provided in the annulus A between the internal housing 20 and the subsea housing 14 or riser R. As discussed above, in the sealed position the gas handler discharge outlet 22 would then be opened so that mud M below the seal 18 can be controlled while drilling with the rotatable pipe P sealed by the preferred internal seals 32 and 34 of the bearing assembly 28. As also discussed above, if a blowout preventer without a gas handler discharge outlet 22 were used, the choke line CL, kill line KL or both could be used to communicate fluid, with the desired pressure and density, below the seal 18 of the blowout preventer to control the mud pressure while drilling.

Because the present invention does not require any significant riser or blowout preventer modifications, normal rig operations would not have to be significantly interrupted to use the present invention. During normal drilling and tripping operations, the assembled internal housing 20 and bearing assembly 28 could remain installed and would only have to be pulled when large diameter drill string components were tripped in and out of the riser R. During short periods when the present invention had to be removed, for example, when picking up drill collars or a bit, the blowout preventer stack BOPS could be closed as a precaution with the diverter D and the gas handler blowout preventer GH as further backup in the event that gas entered the riser R.

As best shown in FIGS. 1, 2 and 4, if the gas handler discharge outlet 22 were connected to the rig S choke manifold CM, the mud returns could be routed through the existing rig choke manifold CM and gas handling system. The existing choke manifold CM or an auxiliary choke manifold (not shown) could be used to throttle mud returns and maintain the desired pressure in the riser below the seal 18 and, therefore, the borehole B.

As can now also be seen, the present invention along with a blowout preventer could be used to prevent a riser from venting mud or gas onto the rig floor F of the rig S. Therefore, the present invention, properly configured, provides a riser gas control function similar to a diverter D or gas handler blowout preventer GH, as shown in FIG. 1, with the added advantage that the system could be activated and in use at all times—even while drilling.

Because of the deeper depths now being drilled offshore, some even in ultra deep water, tremendous volumes of gas are required to reduce the density of a heavy mud column in a large diameter marine riser R. Instead of injecting gas into the riser R, as described in the Background of the Invention, a blowout preventer can be positioned in a predetermined location in the riser R to provide the desired initial column of mud, pressurized or not, for the open borehole B since the present invention now provides a barrier between the one fluid, such as seawater, above the seal 18 of the subsea housing 14, and mud M, below the seal 18. Instead of injecting gas into the riser above the seal 18, gas is injected below the seal 18 via either the choke line CL or the kill line KL, so less gas is required to lower the density of the mud column in the other remaining line, used as a mud return line.

Turning now to FIG. 11, an elevation view of one embodiment for positioning a rotating control head in a marine riser R is shown. As shown in FIG. 11, the marine riser R is comprised of three sections, an upper tubular 1100, a subsea housing 1105, and a lower body 1110. The lower body 1110 can be an apparatus for attaching at a borehole, such as a wellhead W, or lower tubular similar to the upper tubular 1100, at the desire of the driller. The subsea housing 1105 is typically connected to the upper tubular by a plurality of equidistantly spaced bolts, of which exemplary bolts 1115A and 1115B are shown. In one embodiment, four bolts are used. Further, the upper tubular 1100 and the subsea housing 1105 are typically sealed with an O-ring 1125A of a suitable substance.

Likewise, the subsea housing 1105 is typically connected to the lower body 1110 using a plurality of equidistantly spaced bolts, of which exemplary bolts 1120A and 1120B are shown. In one embodiment, four bolts are used. Further, the subsea housing 1105 and the lower body 1110 are typically sealed with an O-ring 1125B of a suitable substance. However, the technique for connecting and sealing the subsea housing 1105 to the upper tubular 1100 and the lower body 1110 are not material to the disclosure and any suitable connection or sealing technique known to those of ordinary skill in the art can be used.

The subsea housing 1105 typically has at least one opening 1130A above the surface that the rotating control head assembly RCH is sealed to the subsea housing 1105, and at least one opening 1130B below the sealing surface. By sealing the rotating control head between the opening 1130A and the opening 1130B, circulation of fluid on one side of the sealing surface can be accomplished independent of circulation of fluid on the other side of the sealing surface which is advantageous in a dual-density drilling configuration. Although two spaced-apart openings in the subsea housing 1105 are shown in FIG. 11, other openings and placement of openings can be used.

In a disclosed embodiment, the rotating control head assembly RCH is constructed from a bearing assembly 1140 and a holding member assembly 1150. The internal structure of the bearing assembly 1140 can be as shown in FIGS. 2, 7, and 10, although other bearing assembly 1140 configurations, including those discussed below in detail, can be used.

As shown in FIG. 11, the bearing assembly 1140 has an interior passage for extending rotatable pipe P therethrough and uses two stripper rubbers 1145A and 1145B for sealingly engaging the rotatable pipe P. Stripper rubber seals as shown in FIG. 11 are examples of passive seals, in that they are stretch-fit and cone shape vector forces augment a closing force of the seal around the rotatable pipe P. In addition to passive seals, active seals can be used. Active seals typically require a remote-to-the-tool source of hydraulic or other energy to open or close the seal. An active seal can be deactivated to reduce or eliminate sealing forces with the rotatable pipe P. Additionally, when deactivated, an active seal allows annulus fluid continuity up to the top of the rotating control head assembly RCH. One example of an active seal is an inflatable seal. The Shaffer Type 79 Rotating Blowout Preventer from Varco International, Inc., the RPM SYSTEM 3000™ from TechCorp Industries International Inc., and the Seal-Tech Rotating Blowout Preventer from Seal-Tech are three examples of rotating blowout preventers that use a hydraulically operated active seal. Co-pending U.S. patent application Ser. No. 09/911,295, filed Jul. 23, 2001, entitled “Method and System for Return of Drilling Fluid from a Sealed Marine Riser to a Floating Drilling Rig While Drilling,” and assigned to the assignee of this application, discloses active seals and is incorporated in its entirety herein by reference for all purposes. U.S. Pat. Nos. 3,621,912, 5,022,472, 5,178,215, 5,224,557, 5,277,249, 5,279,365, and 6,450,262B1 also disclose active seals and are incorporated in their entirety herein by reference for all purposes.

FIG. 35 is an elevation view of a bearing assembly 3500 with one embodiment of an active seal. The bearing assembly 3500 can be placed on the rotatable pipe, such as pipe P in FIG. 11, on a rig floor. The lower passive seal 1145B holds the bearing assembly 3500 on the rotatable pipe while the bearing assembly 3500 is being lowered into the marine riser R. As the bearing assembly 3500 is lowered deeper into the water or TIH, the pressure in the accumulators 3510 and 3511 increase. Lubricant, such as oil, is transferred from the accumulators 3510 and 3511 through the bearings 3520, and through a communication port 3530 into an annular chamber 3540 behind the active seal 3550. As the pressure behind the active seal 3550 increases, the active seal 3550 moves radially onto the rotatable pipe creating a seal. As the rotatable pipe is pulled through the active seal 3550, tool joints will enter the active seal 3550 creating a piston pump effect, due to the increased volume of the tool joint. As a result, the lubricant behind the active seal 3550 in the annular chamber 3540 is forced back though the communication port 3530 into the bearings 3520 and finally into the accumulators 3510 and 3511. After use, the bearing assembly 3500 can be retrieved or POOH though the marine riser R. As the water depth decreases, the amount of pressure exerted by the accumulators 3510 and 3511 on the active seal 3550 decreases, until there is no pressure exerted by the active seal 3550 at the surface. In another embodiment, additional hydraulic connections can be used to provide increased pressure in the accumulators 3510 and 3511. It is also contemplated that a remote operated vehicle (ROV) could be used to activate and deactivate the active seal 3550.

FIG. 12 shows the running tool 1190 extended below the holding member assembly 1150 when latched to the subsea housing 1105, as will be discussed below in detail. Additionally shown are passive latching members 1199C (in phantom) and 1199D. One skilled in the art will recognize that the number of passive latching members can vary.

Because the running tool 1190 has been extended downwardly in FIG. 12, the stripper rubber 1145B is shown in a sealed position, sealing the bearing assembly 1140 to a section of rotatable pipe 1210, which is connected to the running tool 1190 at a connection point 1200, shown as a threaded connection in phantom. One skilled in the art will recognize other connection techniques can be used.

Additionally, as best shown in FIGS. 16 and 19, a passive latching technique allows latching the holding member assembly 1150 to the subsea housing 1105. A plurality of passive holding members of the holding member assembly 1150 engage with a plurality of passive internal formations of the subsea housing 1105, not visible in detail in FIG. 11. Two such passive holding members 1160A and 1160B are shown in FIG. 11. In one embodiment, as shown in FIG. 16 four such passive holding members 1160A, 1160B, 1160C, and 1160D and passive internal formations are used.

FIG. 19 is a detail elevation view of a portion of an inner surface of the subsea housing 1105 showing a typical passive internal formation 1900 providing a profile, in the form of a J-shaped indentation in a reduced diameter section 1930 of the subsea housing 1105. Identical passive internal formations are equidistantly spaced around the inner surface of the holding member assembly 1150. Each of the passive holding members of the holding member assembly 1150 engages a vertical section 1910 of the passive internal formation 1900, possibly requiring rotation to properly align with the vertical section 1910. A curved upper end 1940 of the vertical section 1910 allows easier alignment of the passive holding members with the passive internal formation 1900. Upon reaching the bottom of the vertical section 1910, rotation of the running tool 1190 rotates the holding member assembly 1150, causing each of the passive holding members to enter a horizontal section 1920 of the passive internal formation 1900, latching the holding member assembly 1150 to the subsea housing 1105. When extraction of the rotating control head assembly RCH is desired, rotation of the running tool 1190 will cause the passive holding members to align with the vertical section 1910, allowing upward movement and disengagement of the holding member assembly 1150 from the subsea housing 1105. A seal 1950, typically in the form of an O-ring, positioned in an interior groove 1951 of the housing 1105 seals the passive holding members 1160A, 1160B, 1160C, and 1160 D of the holding member assembly 1150 with the subsea housing 1105.

A pressure relief mechanism attached to the passive holding members 1160A, 1160B, 1160C, and 1160D allows release of borehole pressure if the borehole pressure exceeds the fluid pressure in the upper tubular 1100 by a predetermined pressure. A plurality of bores or openings 1165A, 1165B, 1165C, 1165D, 1165E, 1165F, 1165G, 1165H, 1165I, 1165J, 1165K, and 1165L, two of which are shown in FIG. 11 as 1165A and 1165B are normally closed by a spring-loaded valve 1170. In one embodiment, a bottom plate 1170 is biased against the bores by a coil spring 1180, secured in place by an upper member 1175. The spring 1180 is calibrated to allow the bottom plate 1170 to open the bores 1165A, 1165B, 1165C, 1165D, 1165E, 1165F, 1165C; 1165H, 11651, 1165J, 1165K, and 1165L at the predetermined pressure. The bores also provide for alleviation of surging during insertion of the rotating control head assembly RCH.

Also shown in FIG. 13, guide members 1300A, 1300B, 1300C, and 1300D are attached to an outer surface of the bearing assembly 1140, for centrally positioning the bearing assembly 1140 away from an inner surface 1320 of the upper tubular 1100. Guide members 1300A and 1300C are shown in elevation view in FIG. 14. As described above, the spreader members 1185 spread the stripper rubbers, allowing fluid passage through openings 1310A, 1310B, 1310C, and 1310D, which reduces surging and swabbing during insertion and removal of the rotating control head assembly RCH.

As shown in FIG. 15, a latching/pressure relief section 1550 is threadedly connected at location 1520 to a threaded section 1510 of the bell-shaped lower portion 1155 of the holding member assembly. Likewise, the latching/pressure relief section 1550 is threadedly connected at location 1540 to an upper portion 1560 of the holding member assembly 1150 at a threaded section 1530. Other attachment techniques can be used. The section 1550 can also be integrally formed with either or both of sections 1560 and 1155 as desired.

The bottom plate 1170 in FIG. 15 is shown opened for pressure relief away from the openings 1165A and 1165B, compressing the coil spring 1180 against annular upper member 1175. This allows fluid communication upwards from the borehole B to the upper tubular side of the subsea housing 1105, as shown by the arrows. Once the borehole pressure is reduced so the borehole pressure no longer exceeds the fluid pressure by the predetermined amount calibrated by the coil spring 1180, the spring 1180 will urge the annular bottom plate 1170 against the openings, closing the pressure relief assembly, as shown below in FIG. 17. Bottom plate 1170 is typically an annular plate concentrically and movably mounted on the latching/pressure relief section 1550. As noted above, the openings and the bottom plate 1170 also assist in reducing surging effects during insertion of the rotating control head assembly RCH.

FIG. 16 shows all the openings 1165A, 1165B, 1165C, 1165D, 1165E, 1165F, 1165G, 1165H, 1165I, 1165J, 1165K, and 1165L are visible in this section view, showing that the openings are equidistantly spaced around member 1600 into which are formed the passive holding members 1160A, 1160B, 1160C, and 1160D. Additionally, vertical sections 1910A, 1910B, 1910C, and 1910D of passive internal formations 1900 are shown equidistantly spaced around the subsea housing 1105 to receive the passive holding members. One skilled in the art will recognize that the number of openings 1165A-1165L is exemplary and illustrative and other numbers of openings could be used.

An alternative threaded section 1710 of the latching/pressure relief section 1550 is shown for threadedly connecting the upper member 1175 to the latching/pressure relief section 1550, allowing adjustable positioning of the upper member 1175. This adjustable positioning of threaded member 1175 allows adjustment of the pressure relief pressure. A setscrew 1700 can also be used to fix the position of the upper member 1175.

FIG. 18 shows another alternative embodiment of the latching/pressure relief section 1550, identical to that shown in FIG. 17, except that a different coil spring 1800 and a different upper member 1810 are shown. Spring 1800 can be a spring of a different tension than the spring 1180 of FIG. 11, allowing pressure relief at a different borehole pressure. Upper member 1810 attaches to section 1550 in a non-threaded manner, such as a snap ring, but otherwise functions identically to upper member 1175 of FIG. 17.

One skilled in the art will recognize that other techniques for attaching the upper member 1175 can be used. Further the springs 1180 of FIGS. 17 and 18 are exemplary and illustrative only and other types and configurations of springs 1180 can be used, allowing configuration of the pressure relief to a desired pressure.

In this embodiment, a subsea housing 2000 is bolted to an upper tubular 1100 and a lower body 1110 similar to the connection of the subsea housing 1105 in FIG. 11. However, in the embodiment of FIGS. 20A and 20B, a different technique for latching and sealing a holding member assembly 2026 is shown. The holding member assembly 2026 is connected to a bearing assembly similarly to how the holding member assembly 1150 is connected to the bearing assembly 1140 in FIG. 11, although the connection technique is not visible in FIGS. 20A-20B. A running tool 1190 is used for insertion and removal of the rotating control head assembly RCH, as in FIG. 11. The passive latching formations, with passive formation 2018A most visible in FIG. 20B, allow the passive latching member 1199A to be further secured in a vertical section 1192, which requires an additional vertical movement for engaging and disengaging the running tool 1190 with the bell-shaped portion 1155 of the holding member assembly, generally designated 2026.

As best shown in FIG. 20A, the holding member assembly 2026 is comprised of an internal housing 2028, with an upper portion 2045, a lower portion 2050, and an elastomer 2055; and an extendible portion 2080.

The upper portion 2045 is connected to the bearing assembly 1140. The lower portion 2050 and the upper portion 2045 are pulled together by the extension of the extendible portion 2080, compressing the elastomer 2055 and causing the elastomer 2055 to extrude radially outwardly, sealing the holding member assembly 2026 to a sealing surface 2000′, as best shown in FIG. 22A, the subsea housing 2000. Upon retracting the extendible portion 2080, the upper portion 2045 and the lower portion 2050 decompress the elastomer 2055 to release the seal with the sealing surface 2000′ of the subsea housing 2000.

An outer annular slidable member 2010 moves vertically in an annular recess 2035. A plurality of passages in the slidable member 2010 of an equal number to the number of upper portion passages allow fluid communication between the interior of the holding member assembly 2026 and the subsea riser when the upper portion passages communicate with the slidable member passages. Upper portion passages 2005A-2005B and slidable member passages 2015A-2015B are shown in FIG. 20A.

Similarly, opposite direction pressure relief is obtained via a plurality of passages through the upper portion 2045 and a plurality of passages through an interior slidable annular member 2025 in recess 2040. Four such corresponding passages are typically used; however, any desired number of passages can be used. Upper portion passages 2020A-2020B and slidable member passages 2030A-2030B are shown in FIG. 20A. When vertical movement of member 2025 communicates the passages, fluid communication allows equalization of pressure similar to that allowed by vertical movement of member 2010 when pressure inside the holding member assembly 2026 exceeds pressure in the upper tubular 1100. FIG. 20A is shown with all of the passages in a closed position. Operation of the bi-directional pressure relief assembly is described below.

Turning to FIG. 20B, latching of the holding member assembly 2026 is performed by a plurality of holding members, spaced equidistantly around the circumference of the lower portion 2050 of the internal housing 2028 of the holding member assembly 2026. Two exemplary passive holding members 2090A and 2090B are shown in FIG. 20B. As best shown in FIG. 25, preferably, four equidistant spaced holding members 2090A, 2090B, 2090C, and 2090D are used, but any desired number can be used. When the holding members are engaged with the subsea housing, as described below, movement of the rotating control head assembly RCH to the subsea housing 2000 is resisted.

Returning to FIG. 20B, a passive internal formation 2002, providing a profile, is annularly formed in an inner surface of the subsea housing 2000. As best shown in FIG. 25, the shape of the passive internal formation 2002 is complementary to that of the holding members 2090A to 2090D, allowing solid latching when fully aligned when urged outwardly by surface 2085 of the extendible portion 2080 of the holding member assembly 2026. However, because an annular passive internal formation 2002 is used, rotation of the holding member assembly 2026 is not required before engagement of the holding members 2090A to 2090D with the passive latching formation 2002.

Each of the holding members 2090A to 2090D, are a generally trapezoid shaped structure, shown in detail elevation view in FIG. 27. An inner portion 2700 of the exemplary member 2090 is a trapezoid with an upper edge 2720, slanted upwardly in an outward direction as shown. Exerting force in a downhole direction by the surface 2085 of extendible portion 2080 on the upper edge 2700 will urge the members 2090A to 2090D outwardly, to latch with the passive latching formation 2002. An outer portion 2710 attached to the inner portion 2700 is generally a trapezoid, with a plurality of trapezoidal extensions or protuberances 2730A, 2730B and 2730C, each of which has an upper edge 2740A, 2740B, and 2740C which slopes downwardly and outwardly. The upper edge 2740A generally extends across the upper edge of the outer portion 2710. In addition to corresponding to the shape of the passive internal formation 2002, the slope of the edges 2740A, 2740B, and 2740C urge the passive holding member inwardly when the passive holding member 2090 is pulled or pushed upwardly against the matching surfaces of the passive internal formation 2002.

Reviewing FIGS. 20B, 21B, and 25 during insertion of the rotating control head assembly RCH, the holding members or chambers 2090A, 2090B, 2090C, and 2090D are recessed into a corresponding number of recesses or chambers 2095A, 2095B, 2095C, and 2095D in the lower portion 2050, with the extensions 2730A, 2730B, 2730C and 2730D serving as guide members to centrally position the holding member assembly 2026 in the upper tubular 1100.

FIG. 28 is a detail elevation view of an exemplary dog member and dog member recess. Each dog member is positioned in a recess or chamber 2810 with a spring-loaded dog assembly 2800. The spring-loaded dog assembly 2800 is comprised of an upper spring 2820A and a lower spring 2820B, attached to an upper urging block 2830A and a lower urging block 2830B, respectively. The urging blocks are shaped so that pressure from the springs on the urging blocks urges a central block 2840 outwardly (relative to the recess 2810). The central block 2840 is generally a trapezoid, with a plurality of trapezoidal extensions 2850A and 2850B for mating with corresponding dog recesses 2860A and 2860B. One skilled in the art will recognize that the number of extensions and recesses shown in FIG. 28, corresponding to the lower and upper dog members and the lower and upper dog recesses, are exemplary and illustrative only, and other numbers of extensions and recesses can be used.

Extensions and recesses are trapezoidal shaped to allow bidirectional disengagement through vector forces, when the dog member 2800 is urged upwardly or downwardly relative to the recesses, retracting into the recess or chamber 2810 when disengaged, without fracturing the central block 2840 or any of the extensions 2850A or 2850B, which would leave unwanted debris in the borehole B upon fracturing. The springs 2820A and 2820B can be chosen to configure any desired amount of force necessary to cause retraction. In one embodiment, the springs 2820 are configured for a 100 kips force.

As shown in FIG. 21A, one portion of the bi-directional pressure relief assembly is in an open position, with passages 2030A, 2020A, 2030B, and 2020B communicating when sliding member 2025 moves downwardly into annular area 2040 (see FIG. 20A) to allow fluid communication between the inside of the holding member assembly 2026 and the annulus 1100, (see FIG. 21 A) of the upper tubular 1100.

Turning to FIG. 22A, one portion of the pressure relief assembly is in an open position, with passages 2005A, 2015A, 2005B, and 2015B communicating when sliding member 2010 moves upwardly in recess 2035.

The extendible portion 2080 is extended into an intermediate position in FIGS. 22A and 22B. The dog members 2070A and 2070B have disengaged from dog recesses 2032, allowing movement of the extendible portion 2080 relative to the upper portion 2045. A shoulder 2060 on the extendible portion 2080 is landed on a landing shoulder 2065 of the upper portion 2045, so that extension of the extendible portion 2080 downwardly pulls the upper portion 2045 toward the lower portion 2050, which is fixed in place by the holding members 2090A, 2090B, 2090C, and 2090D engaging with the passive internal formation 2002 of the subsea housing 2000. This compresses the elastomer 2055, causing it to extrude radially outwardly, sealing the holding member assembly 2026 with the sealing surface 2000′ of the subsea housing 2000.

Turning now to FIGS. 23A and 23B, the extendible portion 2080 is in the lower or fully extended position. As in FIG. 22A, the upper dog members 2070A and 2070B are disengaged from the upper dog recesses 2032, while shoulder 2060 is landed on shoulder 2065, causing the elastomer 2055 to be fully compressed, extruding outwardly to seal the holding member assembly 2026 with the sealing surface 2000, subsea housing 2000. Further, in FIG. 23B, the lower dog members 2008A and 2008B are engaged with the lower dog recesses 2012, blocking the extendible portion 2080 in the lower or fully-extended position.

This blocking of the extendible portion 2080 allows disengaging the running tool 1190, as shown in FIG. 23B, without the extendible portion 2080 retracting upwardly, which would decompress the elastomer 2055 and unseal the holding member assembly 2026 from the subsea housing 2000.

As stated above, to disengage the holding member assembly 2026, an operator will recognize a decreased “weight on bit” when the running tool is ready to be disengaged. As shown best in FIG. 22B and 23B, an operator momentarily reverses the rotation of the drill string, while pulling the running tool 1190 slightly upwards, to release the passive latching members 1199 from the position 1192 of the J-shaped passive formations 1199. The running tool 1190 can then be lowered, causing the passive latching members 1199 to exit through the vertical section 1198 of each formation 1197A and 1197B, as shown in FIG. 23B. The running tool 1190 can then be lowered and normal rotation resumed, allowing the running tool to move downward through the lower body 1110 toward the borehole.

Turning now to FIG. 24, a detail elevation view of the pressure relief assembly of FIGS. 20A, 21A, 22A, and 23A is shown, with the lower slidable member 2025 in a lower position, communicating the passages 2020 and 2030 for fluid communication while the upper slidable member 2010 is in a lower position, which ensures the passages 2015 and 2005 are not communicating, preventing fluid communication. Additionally, FIG. 24 shows a plurality of seals for sealing the upper slidable member 2010 to the upper portion 2045 of the holding member assembly 2026. Shown are seals 2400A, 2400B, and 2400C, typically O-rings of a suitable material. Also shown are seals for sealing the lower slidable member 2025 to the upper portion 2045, with exemplary seals 2410A, 2410B, and 2410C, typically O-rings of a similar material as used in seals 2400A, 2400B, and 2400C. Other numbers, positions, arrangements, and types of seals can be used. A coil spring 2420 biases the upper slidable member 2010 in a downward or closed position. Similarly, a coil spring 2430 biases the lower sliding member 2025 in an upward or closed position. When fluid pressure in the interior of the holding member assembly exceeds the fluid pressure in the subsea riser R by a predetermined amount, fluid will pass through the passage 2005, forcing the upper sliding member 2010 upwardly against the spring 2420, until the passages 2005 align with the passages 2015, allowing fluid communication and pressure relief. Likewise, when fluid pressure in the subsea riser R exceeds the fluid pressure in the holding member assembly by a predetermined amount, fluid will pass through the passage 2020, forcing the lower sliding member 2025 downwardly against the spring 2430, until the passages 2030 align with the passages 2020, allowing fluid communication and pressure relief. One skilled in the art will recognize that the springs 2420 and 2430 can be configured for any pressure release desired. In one embodiment, springs 2420 and 2430 are configured for a 100 PSI excess pressure release. One skilled in the art will also recognize that the spring 2420 can be configured for a different excess pressure release amount than the spring 2430.

Springs 2420 and 2430 bias slidable members 2010 and 2025, respectively, toward a closed position. When fluid pressure interior to the holding member assembly 2026 exceeds fluid pressure exterior to the holding member assembly 2026 by a predetermined amount, fluid will pass through the passages 2005, forcing the slidable member 2010 upward against the biasing spring 2420 until the passages 2015 are aligned with the passages 2005, allowing fluid communication between the interior of the holding member 2026 and the exterior of the holding member 2026. Once the excess pressure has been relieved, the slidable member 2010 will return to the closed position because of the spring 2420.

FIGS. 26A and 26B are a detail elevation view of pressure compensation mechanisms 2600 and 2660 of the bearing assembly 1140 of the embodiments of FIGS. 11-25B. Pressure compensation mechanisms 2600 and 2660 allow for maintaining a desired lubricant pressure in the bearing assembly 1140 at a higher level than the fluid pressure within the subsea housing above or below the seal. FIGS. 26C and 26D are detailed elevation views of two orientations of the pressure compensation mechanism 2600. FIGS. 26E and 26F are detailed elevation views of lower pressure compensation mechanism 2660, again in two orientations.

A chamber 2615 is filled with oil or other hydraulic fluid. A barrier 2610, such as a piston, separates the oil from the sea water in the subsea riser. Pressure is exerted on the barrier 2610 by the sea water, causing the barrier 2610 to compress the oil in the chamber 2615. Further, a spring 2605, extending from block 2635, adds additional pressure on the barrier 2610, allowing calibration of the pressure at a predetermined level. Communication bores 2645 and 2697 allow fluid communication between the bearing chamber—for example, referenced by 2650A, 2650B in FIG. 26D and FIG. 26F, respectively—and the chambers 2615, 2695 pressurizing the bearing assembly 1140.

A corresponding spring 2665 in the lower pressure compensation mechanism 2660 operates on a lower barrier 2690, such as a lower piston, augmenting downhole pressure. The springs 2605 and 2665 are typically configured to provide a pressure 50 PSI above the surrounding sea water pressure. By using upper and lower pressure compensation mechanisms 2600 and 2660, the bearing pressure can be adjusted to ensure the bearing pressure is greater than the downhole pressure exerted on the lower barrier 2690.

In the upper mechanism 2600, shown in FIG. 26C, a nipple 2625 and pipe 2620 are used for providing oil to the chamber 2615. Access to the nipple 2625 is through an opening 2630 in the bearing assembly 1140. In one embodiment, the upper and lower pressure compensation mechanisms 2600 and 2660 provide 50 PSI additional pressure over the maximum of the seawater pressure in the subsea housing and the borehole pressure.

FIGS. 26E and 26F show the lower pressure compensation mechanism 2660 in elevation view. Passages 2675 through block 2680 allow downhole fluid to enter the chamber 2670 to urge the barrier 2690 upward, which is further urged upward by the spring 2665 as described above. Each of the barriers 2690 and 2610 are sealed using seals 2685A, 2685B and 2640A, 2640B. The upper and lower pressure compensation mechanisms 2600 and 2660 together ensure that the bearing pressure will always be at least as high as the higher of the sea water pressure being exerted on the upper pressure compensation mechanism 2600 and the downhole pressure being exerted on the lower pressure compensation mechanism 2660, plus the additional pressure caused by the springs 2605 and 2665. One advantage of the disclosed pressure compensation technique is that exterior hydraulic connections are not needed to adjust for changes in either the sea water pressure or the borehole pressure.

FIGS. 29B, 32B, and 33-34 illustrate that the bearing assembly 1140 can be implemented using a unidirectional pressure relief mechanism 2910, which comprises the lower pressure relief mechanism of the bi-directional pressure relief mechanism shown in FIGS. 20A, 21A, 22A, 23A and 24, allowing pressure relief from excess downhole pressure, but using the ability of stripper rubbers 1145 to “burp” to allow relief from excess interior pressure.

weatherford mp 10 mud pump free sample

You Might Also Be Interested In