Patent Application
20120305120
The present invention relates generally to pressure regulation within a system. More particularly, the present invention relates to a novel pressure-compensated accumulator bottle for such systems.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
As will be appreciated, supplies of oil and natural gas have a profound effect on modern economies and civilizations. Devices and systems that depend on oil and natural gas are ubiquitous. For instance, oil and natural gas are used for fuel in a wide variety of vehicles, such as cars, airplanes, boats, and the like. Further, oil and natural gas are frequently used to heat homes during winter, to generate electricity, and to manufacture an astonishing array of everyday products.
In order to meet the demand for these resources, companies often spend a significant amount of time and money searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired resource is discovered below the surface of the earth, a drilling system is often employed to access and extract the resource. These drilling systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems include a wide array of components, such as valves, that control drilling or extraction operations. Often, some of these components are controlled through pressure variation, such as that provided by a hydraulic control system.
As may be appreciated, hydraulic systems often include accumulator bottles that facilitate operation of the system. Generally, these accumulator bottles may be used to store pressurized hydraulic fluid in a hydraulic circuit; the accumulator bottle typically receives hydraulic fluid from the circuit in low-demand periods and returns the hydraulic fluid to the circuit as needed to supplement flow and pressure within the system. In many instances, a typical accumulator bottle will include a first chamber that communicates with the hydraulic circuit and a second chamber that contains a pressurized gas. As will be appreciated, the pressure setting of the gas is known as a “pre-charge”, and generally controls the amount of energy which may be stored by the accumulator bottle. Excessive pre-charge pressure may prevent the accumulator bottle from receiving hydraulic fluid, while insufficient pressure may not provide enough energy to force such fluid back into the hydraulic circuit when needed. Further, the amount of pre-charge desired generally depends on the ambient pressure in which the accumulator bottle is intended to operate. Consequently, movement of a typical accumulator bottle from one ambient pressure to another (e.g., between different operational depths) would often necessitate an adjustment to the pre-charge.
Certain aspects commensurate in scope with the originally claimed invention are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
Embodiments of the present invention generally relate to a novel pressure-compensated accumulator bottle. In certain embodiments, the accumulator bottle includes a housing and internal components that generally divide the interior of the housing into a plurality of regions for receiving fluids. For instance, in some embodiments, the interior of the accumulator bottle includes a first region for receiving a hydraulic fluid, a second region for receiving a pressure compensation oil, and a third region for receiving fluid from the ambient environment in which the accumulator bottle is disposed. In some of these embodiments, a first piston generally divides the first and second regions, and generally cooperates with a spring within the housing to regulate flow of hydraulic fluid in and out of the first region. Additionally, in at least one embodiment, a second, floating piston generally divides the second and third regions and facilitates automatic pressure-compensation of the accumulator bottle via compression of the pressure compensation oil in the second region in response to ambient pressure in the third region. Other embodiments, however, may include a greater or lesser number of such regions for providing this pressure-compensation functionality. Further, additional embodiments of the present invention may also include various hydraulic circuits and systems including such an accumulator bottle.
Various refinements of the features noted above may exist in relation to various aspects of the present invention. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present invention alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of the present invention without limitation to the claimed subject matter.
These and other features, aspects, and advantages of the present invention 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:
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, 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. Moreover, the use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience, but does not require any particular orientation of the components.
Turning now to the present figures, an exemplary accumulator bottle 10 is illustrated in
Various internal components and features of the accumulator bottle 10 may be better understood with reference to the cross-sectional view of
The exemplary enclosure 40 generally defines the chamber 28 within the housing 12. In one embodiment, the enclosure is positioned within the central body 14 such that the chambers 26 and 28 are substantially coaxial, although other arrangements are also envisaged. The accumulator bottle 10 and its components may be configured to allow the enclosure 40 to undergo relative motion within the housing 12, such as generally illustrated in
In the presently illustrated embodiment, fluid ports 50 are provided through an internal partition of the housing 12 to allow fluid communication between the chambers 24 and 26, while fluid ports 52 allow fluid communication between the chambers 26 and 28. Pistons 32 and 44, however, generally prevent fluid communication between the chamber 26 and other hydraulic components via the aperture 30, or between the chamber 26 and the external environment through aperture 48. As will be appreciated, various seals 56 may be provided between components of the accumulator bottle 10 to reduce or prevent fluid transfer between different areas of the housing 12.
During operation, and with reference to
It should be noted that the relative volumes of the regions 60, 62, and 64 will change during operation depending on the position of the pistons 32 and 44. As hydraulic fluid is introduced into the region 60 via the aperture 30, pressure within the region 60 causes the piston 32 (and the enclosure 40 if coupled to the piston 32) to move from the position illustrated in
Notably, in addition to the spring 34, the pressure of a fluid contained in the region 62 may also apply a biasing force on the piston 32. In some embodiments, this fluid may be a non-corrosive, low-compressibility oil that facilitates the use of less-expensive high-strength materials, such as steels, to form various internal components of the accumulator bottle 10, rather than more-expensive corrosion-resistant materials. Other fluids and materials, however, may instead be used within the region 62 in full accordance with the present techniques. While external fluids, such as water in subsea applications, are allowed to enter the region 64 through the aperture 48, the piston 44 prohibits fluid transfer between the regions 62 and 64. More specifically, in at least one embodiment, the piston 44 is a floating piston that moves within the chamber 28 in response to the ambient pressure of the environment in which the accumulator bottle 10 is disposed, allowing communication between the regions 62 and 64 without fluid transfer.
In one embodiment, the movement of the piston 44 is generally independent of the compression of the spring 34, thus allowing the amount of energy capable of being stored by the accumulator bottle 10 to vary according to environmental conditions even when the piston 32 is fully open within the chamber 24 and cannot further compress the spring 34. For instance, as the ambient pressure of the environment in which the accumulator bottle 10 is disposed increases, the pressure within the region 64 forces the piston 44 to travel in the direction indicated by arrow 66 in
Alternatively, as illustrated in
Consequently, in one embodiment, this ambient pressure-over-springs design of the exemplary accumulator bottle 10 facilitates automatic adjustment of the energy storage capacity of the accumulator bottle 10 in response to the ambient pressure in which it is disposed. Notably, this self-adjustment of the pressure-compensated accumulator bottle 10 facilitates its optimal use over a wide range of ambient pressures and operational depths, while reducing or eliminating the need for time-consuming pre-charge maintenance or adjustment of accumulator bottles for different operating depths or conditions. This, in turn, results in reduced manufacturing and maintenance costs for systems employing the accumulator bottle 10. Additionally, the floating piston 44 provides further pressure compensation functionality by accommodating the expansion of fluid within the region 62 upon an increase in the ambient temperature. It should also be noted that while certain embodiments of the accumulator bottle 10 may comprise other components in addition to the components explicitly discussed above (e.g., the housing 12, the pistons 32 and 44, the springs 34 and 46, and the like), other embodiments in accordance with the present techniques may consist of, or consist essentially of, these components or some sub-combination thereof.
An exemplary hydraulic circuit 72 including an accumulator bottle 10 is depicted in
In some embodiments, one or more hydraulic circuits 72 may be integrated into a larger system, such as the exemplary drilling system 82 of
The stack equipment 90 may include a number of components, such as blowout preventers and/or production or “Christmas” trees, for extracting the desired resource from the wellhead 92. In the presently illustrated embodiment, operation of the stack equipment 90 is controlled by an exemplary control system 94. The exemplary control system 94 includes one or more hydraulic circuits 72, each having at least one accumulator bottle 10 and controlling flow through the system 82. In some embodiments, the control system 94 includes one or more control pods of a blowout preventer.
It will be appreciated that, traditionally, multiple accumulator bottles may have been employed for each hydraulic circuit of a control pod to enable operation of the circuit over a small range of operating depths (e.g., a 200-foot range); any variation outside of this limited range would generally necessitate adjustment of the pre-charge level in such accumulator bottles. In at least one embodiment of the present invention, however, the pressure-compensating design of the exemplary accumulator bottle 10 allows fewer bottles 10 to be used as the accumulator bottles in each hydraulic circuit, as generally illustrated in
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
This application claims priority to U.S. Provisional Patent Application No. 60/993,110, entitled “Pressure-Compensated Accumulator Bottle”, filed on Sep. 10, 2007, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60993110 | Sep 2007 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12669038 | Jan 2010 | US |
| Child | 13587871 | US |
