Patent Application
20150167652
The present technology relates generally to fluid pumps and, more specifically, to submersible fluid pumps of the type used in wells such as oil wells for handling multiphase fluids.
Generally, pumping systems are used in a wide variety of environments, including wellbore applications for pumping production fluids, such as water or petroleum. The pumping systems typically include, among other components, a submersible pump that provides for the pumping of high volumes of fluid, such as for use in oil wells which produce large quantities of water, or high volume water wells and a submersible motor for operating the electric submersible pump. A typical submersible pump utilizes numerous pump stages for pumping fluid to the surface from the well. Recovery of hydrocarbon resources has led to the development of advanced drilling and completion strategies for wells in gas and oil reserves. Many of these wells deviate from a straight path in order to enter production zones and follow geological formations that are often within a narrow band. Further, these directionally drilled wells for production of natural gas or shale oil often extend vertically down to reach the depth of the production formation and then extend horizontally along the formation. The flow of fluids produced in the horizontal section can be very non-uniform depending on the rates at which fluids including water, oil, and gas enter the flow. The fluids may flow in slugs or streams depending on the inclination of the wellbore. Furthermore, the proppants such as sand used in hydraulic fracturing procedures may remain in the wellbore after well completion and additional solids may be produced throughout the life of the well. This causes inferior production rates by the traditional pumping systems due to difficulty in maintaining required head pressure and handling multiphase fluids. The life of the pumps is also degraded by the solids.
There is therefore a desire for a system and method that allow increased production rates and life of the pumping systems used in deviated wellbores.
In accordance with an example of the technology, a method of isolating a production fluid from a fluid-containing reservoir is provided. The method includes disposing a first pump within a horizontal section of a production well. The method also includes disposing a second pump within a vertical section of the production well. Further, the method includes pumping a reservoir fluid via the first pump towards the second pump. The method also includes capturing at least a portion of the reservoir fluid from the first pump in a fluid-retaining section located around the second pump. Furthermore, the method includes pumping the reservoir fluid captured in the fluid-retaining section to a fluid containment vessel via the second pump to provide an isolated production fluid.
In accordance with an example of the technology, a pumping system for isolating a production fluid from a fluid-containing reservoir is provided. The pumping system includes a first pump configured to be deployed in a horizontal section of a production well for pumping a reservoir fluid. The pumping system also includes a second pump configured to be deployed in a vertical section of the production well. The pumping system further includes a second pump configured to be deployed in a vertical section of the production well. The first pump and the second pump are in fluid communication via a production tubing string.
In accordance with an example of the technology, a subterranean pumping system is provided. The subterranean pumping system includes a first pump configured to be deployed in a horizontal section of a production well for pumping a reservoir fluid. The subterranean pumping system also includes a second pump configured to be deployed in a vertical section of the production well. Further, the subterranean pumping system includes a fluid-retaining section disposed around the second pump for holding fluids that are pumped from the first pump. Further, the subterranean pumping system includes a control system configured for controlling flow of fluids pumped from the first pump, the second pump and maintaining pan optimal level of fluids in the fluid-retaining section.
These and other features, aspects, and advantages of the present technology will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
When introducing elements of various embodiments of the present technology, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters are not exclusive of other parameters of the disclosed examples.
Further, the pumping system 10 includes a fluid-retaining section 25 disposed around the second pump 22. The production well 16 is divided between two sections forming a first zone that encloses the first pump 12 and a second zone that encloses the second pump 22 by disposing a production packer 27. The second zone enclosing the second pump 22 forms the fluid-retaining section 25 configured to capture the reservoir fluid pumped from the first pump 12. The captured reservoir fluid in the fluid-retaining section 25 is pumped by the second pump 22 to the wellhead 28 above ground and further to a fluid containment vessel 30.
Furthermore, each of the first pump 12 and the second pump 22 are controlled by a first power supply unit 32 and a second power supply unit 34 respectively located above ground. It is to be noted that each of the first power supply unit 32 and the second power supply unit 34 includes an electrical supply unit, a hydraulic supply unit, and a pneumatic unit. Non-limiting examples of each of the first pump 12 and the second pump 22 includes a turbo pump, a progressive cavity pump, a reciprocating piston pump and a jet pump. The turbo pump may include a centrifugal pump or an axial pump and combinations thereof. Further, in one example each of the first pump 12 and the second pump 22 is a multistage pump. In one embodiment, the first pump 12 includes an electric submersible pump having one or more helico-axial configuration for pumping multiphase fluids having, high gas volume fractions. The second pump 22 includes an electric submersible pump having one or more pump stages in radial or mixed flow configuration for generating desired head pressure for lifting the fluids from the fluid-retaining section 25 to the wellhead 16 located aboveground. As shown, the pumping system 10 includes a first power delivery conduit 36 and a second power delivery conduit 38 that are disposed in the production well 16 for delivering power from the first power supply unit 32 and the second power supply unit 34 to the first pump 12 and the second pump 22 respectively.
Further, the pumping system 40 may be operated by a control system 46 located aboveground and configured for controlling flow rate of fluids pumped from the first pump 12 and the second pump 22. In one embodiment, the pumping system 40 includes one or more control systems located above or below ground and configured to control the operating speed of the first pump 12 and the second pump 22. Alternatively, the pumping system 40 may be operated to pump any gaseous and liquid multiphase fluid that permits pumping system 40 to operate as described herein. The control system 46 may also be configured to maintain an optimal level of fluids in the fluid retaining section 25.
In one embodiment, as shown in
Advantageously, the present invention is directed towards improving operability and durability of the pumping system used in directionally drilled wells. The present pumping system and method allows efficient pumping of multiphase fluids including solids, liquids and gases in production of unconventional oil and gas wells.
Furthermore, the skilled artisan will recognize the interchangeability of various features from different examples. Similarly, the various methods and features described, as well as other known equivalents for each such methods and feature, can be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular example. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or improves one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
While only certain features of the technology have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the claimed inventions.
