MODULAR MUD LIFT PUMP ASSEMBLY
A method and system for lifting drilling mud from subsea to a drilling vessel, which uses a pump having a body with a chamber, and a bladder in the chamber. The bladder attaches to the body and defines water and mud sides in the chamber. A mud inlet valve allows mud into the mud side of the chamber; which moves the bladder into the water side and urges water in the water side from the chamber and through a water exit valve. Pressurized water enters the chamber through a water inlet valve, which in turn pushes the bladder and mud from the chamber through a mud exit valve. The bladder separates the mud and water as it reciprocates in the chamber. The travel of the bladder in the chamber is controlled to prevent damage from contact with the chamber.
1. Field of Invention
The present disclosure relates in general to a modular system for pumping drilling mud from subsea to above the sea surface.
2. Description of Prior Art
Subsea drilling systems typically employ a vessel at the sea surface, a riser connecting the vessel with a wellhead housing on the seafloor, and a drill string. A drill bit is attached on a lower end of the drill string, and used for excavating a borehole through the formation below the seafloor. The drill string is suspended subsea from the vessel into the riser, and is protected from seawater while inside of the riser. Past the lower end of the riser, the drill string inserts through the wellhead housing just above where it contacts the formation. Generally, a rotary table or top drive is provided on the vessel for rotating the string and bit. Drilling mud is usually pumped under pressure into the drill string, and is discharged from nozzles in the drill bit. The drilling mud, through its density and pressure, controls pressure in the well and cools the bit. The mud also removes formation cuttings from the well as it is circulated back to the vessel. Traditionally, the mud exiting the well is routed through an annulus between the drill string and riser. However, as well control depends at least in part on the column of fluid in the riser, the effects of corrective action in response to a well kick or other anomaly can be delayed.
Fluid lift systems have been deployed subsea for pressurizing the drilling mud exiting the wellbore. Piping systems outside of the riser carry the mud pressurized by the subsea lift systems. The lift systems include pumps disposed proximate the wellhead, which reduce the time for well control actions to take effect.
SUMMARY OF THE INVENTIONDisclosed herein are examples of a system and method of lifting drilling fluid from a subsea wellbore to above the sea surface. In one example, disclosed is a system for lifting the drilling fluid from a subsea wellbore that includes a drilling riser having a return flow of the drilling fluid, a subsea module coupled with the drilling riser and having piping, and that is transportable to the drilling riser on a vessel having a capacity that is less than a capacity of a rig used in conjunction with the drilling riser. Also included is a riser module coupled with the drilling riser and having controls, and that is transportable to the drilling riser on the vessel, and a pump module coupled with the drilling riser. The pump module has a pump that is in fluid communication with the drilling fluid in the drilling riser via the piping in the subsea module and that is in communication with the controls in the riser module. The pump module is transportable to the drilling riser on the vessel. The pump module can be a first pump module, in this example the system further includes a second pump module that is symmetric and interchangeable with the first pump module. Further in this example, each pump module includes three pumps. Each pump may have a housing, a water space in the housing, a mud space in the housing that is in pressure communication with the water space, a bladder mounted in the housing having a side in contact with the water space and an opposing side in contact with the mud space, and that defines a barrier between the water and mud space. Optionally, the pump module, the subsea module, and the riser module each have a weight less than 50 metric tons. In an optional embodiment, the piping in the subsea module includes a portion for bypassing the pump module.
Also disclosed herein is an example method of lifting drilling fluid from subsea that includes providing a pump module having a series of pumps, providing a riser module having controls for the pump module, providing a subsea module having piping, forming a mud pump kit by coupling together the pump module, riser module, and subsea module, coupling the mud pump kit with a subsea riser, flowing mud from the riser to the pump module via the subsea module, and lifting the mud to above sea surface by pressurizing the mud with the pumps in the pump module. Alternatively, a second pump module can be included that is symmetric with the first pump module, so that the first and second pump modules can be interchangeable. In an example, the pump module, the subsea module, and the riser module are transported individually to a drilling riser on the sea surface with a vessel having a limited capacity. A spare pump module can be optionally provided, where the method further includes replacing the pump module with the spare pump module. The pump module can be controlled with the controls from the riser module. In one alternative, mud flow is bypassed around the pump module and through the subsea module.
Another example method of lifting drilling fluid from subsea includes providing first and second pump modules that are symmetric to one another. In this example, each of the pump modules has a series of pumps. The method further includes providing a riser module having controls for the pump modules, providing a subsea module having piping; and transporting the first pump module, the second pump module, the riser module, and subsea module on a vessel and to an offshore rig. Here, each of the pump modules, the riser module, and subsea module are individually transported to the rig on the vessel. A mud pump kit is formed by coupling together the pump modules, riser module, and subsea module on the offshore rig, and the mud pump kit is coupled with a subsea riser that is operated in conjunction with the offshore rig. Mud is flowed from the riser to the pump modules via the subsea module, and the mud is lifted to above sea surface by pressurizing the mud in the pump modules. A spare pump module can optionally be provided; where the spare pump module is used to replace one of the first or second pump modules. In one alternative, the controls in the riser module include a processor and hydraulic power units, the method of this example can further include using the processor to selectively open and close valves provided with the pump modules.
Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTIONThe method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.
It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.
Shown in
A lower open space 54 is formed on a lower end of bladder 42 distal from upper open space 48, which in the example of
Still referring to
Water may be selectively delivered into water space 46 via a water supply line 76 (
A water inlet valve 96 shown in water inlet lead line 78 provides selective water communication from vessel 22 (
In one example of operation of pump 38 of
An example of pressurizing mud within mud space 44 is illustrated in
As illustrated in
The lift pump assembly 34 of
Downstream of valves 108A-C, pressurization tubing 104A-C connects to a tubing header 112, through which water in the pressure balance circuit 102 can be discharged to ambient. In the example of
Still referring to the example of
In some examples of use, pumps 38A-C operate under “managed pressure drilling operations” where mud flow rates are reduced, but pressure of the mud to the pumps 38A-C is increased. During these conditions, the flow path to ambient through the pressure balance circuit 102 and from lines 78A-C can allow pressure in pumps 38A-C to drop below a threshold value so that pumps 38A-C will uncontrollably fill with mud during a subsequent pumping cycle. One example of operation to address the unacceptable pressure drop includes diverting flow in tubing header 112 that is being discharged from pressure balance circuit 102 through bypass line 128. In this example, block valve 130 is set into a closed position and block valve 132 is open. In an optional example, controller 100 delivers instructions for opening/closing of the block valves 130, 132. As indicated above, bypass line 128 terminates into water discharge line 94 upstream of control valve 124, which is maintained at a pressure sufficiently above ambient so that a backpressure can be exerted onto pressure balance circuit 102. In the example of
Referring now to
A solids recovery unit (SRU) 145 is shown above the pump modules 140, 142, and a subsea rotating device (SRD) 146 attaches to an upper end of SRU 145. An upper end of SRD 146 flangedly attaches to a riser joint 148; where in one example a substantial portion of the riser 26A between SRD 146 and vessel 22 (
In the example of
In an example, modules 136, 137, 140, 142 are modular elements that can be transported separately to the vessel 22 (
In an optional embodiment, pump modules 140, 142 are individually detachable from the pump kit 134, and thus further enhancing modularity of the pumping system. Dedicated piping (not shown) may be routed from SRU 145 and separately to each module 140, 142 so that one of the modules 140, 142 can remain operational while the other is removed or otherwise out of service. Further, spare modules can be kept on site for one or both modules 140, 142, and can installed in place of a one of the modules 140, 142 with little or no stoppage of operation of pumping mud to the vessel 22.
Yet further optionally, BOP 28A is a BOP stack, whose upper portion includes an annular blowout preventer and is part of a lower marine riser package (LMRP). Additionally, LMRP can include controls, a multiplexer unit, and pods. In an embodiment, modules 136, 137, 140, 142, SRU 145, SRU 146, BOP 28A, and riser joints 116 are delivered to the vessel 22 (
Referring now to
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.
Claims
1. A system for lifting drilling fluid from a subsea wellbore comprising:
- a drilling riser having a return flow of the drilling fluid;
- a subsea module coupled with the drilling riser and having piping, and that is transportable to the drilling riser on a vessel having a capacity that is less than a capacity of a rig used in conjunction with the drilling riser;
- a riser module coupled with the drilling riser and having controls, and that is transportable to the drilling riser on the vessel; and
- a pump module coupled with the drilling riser, and having a pump that is in fluid communication with the drilling fluid in the drilling riser via the piping in the subsea module and that is in communication with the controls in the riser module, and that is transportable to the drilling riser on the vessel.
2. The system of claim 1, wherein the pump module comprises a first pump module, the system further comprising a second pump module that is symmetric and interchangeable with the first pump module.
3. The system of claim 2, wherein each pump module comprises three pumps.
4. The system of claim 3, wherein each pump comprises a housing, a water space in the housing, a mud space in the housing that is in pressure communication with the water space, a bladder mounted in the housing having a side in contact with the water space and an opposing side in contact with the mud space, and that defines a barrier between the water and mud space.
5. The system of claim 1, wherein the pump module, the subsea module, and the riser module each have a weight less than 50 metric tons.
6. The system of claim 1, wherein the piping in the subsea module includes a portion for bypassing the pump module.
7. A method of lifting drilling fluid from subsea comprising:
- providing a pump module having a series of pumps;
- providing a riser module having controls for the pump module;
- providing a subsea module having piping;
- forming a mud pump kit by coupling together the pump module, riser module, and subsea module;
- coupling the mud pump kit with a subsea riser;
- flowing mud from the riser to the pump module via the subsea module; and
- lifting the mud to above sea surface by pressurizing the mud with the pumps in the pump module.
8. The method of claim 7, wherein the pump module comprises a first pump module, the method further comprising providing a second pump module that is symmetric with the first pump module, so that the first and second pump modules are interchangeable.
9. The method of claim 7, wherein the pump module, the subsea module, and the riser module are transported individually to a drilling riser on the sea surface with a vessel having a limited capacity.
10. The method of claim 7, further comprising providing a spare pump module, and replacing the pump module with the spare pump module.
11. The method of claim 7, wherein the pump module is controlled with the controls from the riser module.
12. The method of claim 7, further comprising bypassing mud flow around the pump module and through the subsea module.
13. A method of lifting drilling fluid from subsea comprising:
- providing first and second pump modules that are symmetric to one another, each of the pump modules having a series of pumps;
- providing a riser module having controls for the pump modules;
- providing a subsea module having piping;
- individually transporting the first pump module, the second pump module, the riser module, and subsea module on a vessel and to an offshore rig;
- forming a mud pump kit by coupling together the pump modules, riser module, and subsea module on the offshore rig;
- coupling the mud pump kit with a subsea riser that is operated in conjunction with the offshore rig;
- flowing mud from the riser to the pump modules via the subsea module; and
- lifting the mud to above sea surface by pressurizing the mud in the pump modules.
14. The method of claim 13, further comprising providing a spare pump module, and replacing one of the first or second pump modules with the spare pump module.
15. The method of claim 13, wherein the controls in the riser module include a processor and hydraulic power units, the method further comprising using the processor to selectively open and close valves provided with the pump modules.
Type: Application
Filed: Feb 21, 2014
Publication Date: Aug 27, 2015
Inventors: Ahmet DUMAN (Houston, TX), Michael John DENK (Houston, TX), Gretchen Aleasha HAINES (Houston, TX)
Application Number: 14/186,828