1. Field of the Invention
The present application relates generally to the field of separating fluids produced from a well, such as oil, gas, and/or water, and particularly to a surface separation system that separates and routes the fluid components.
2. Background Art
Oil well production typically involves bringing significant volumes of undesired fluid (e.g., salt water) to the surface. This “produced water” often accounts for 80 to 90 percent, or more, of the total well fluid volume produced, creating significant operational issues and expense for producers.
The produced water generally must be treated and re-injected to a subterranean reservoir, both for disposal and to maintain reservoir pressure. Because treatment facilities are typically extensive and expensive, they are generally housed in a central facility. This requires transporting the produced fluids, usually by pipeline, to and from the treatment facility. Transporting, treating, and disposing of produced water can cost anywhere from a few cents to several dollars per barrel. In some instances, transporting great distances creates bottlenecks, is highly inefficient, and becomes cost-prohibitive.
In certain cases fluid separation can be performed downhole before the undesired fluid is brought to the surface. However, in other cases that is not be feasible due to, for example, cost, operational complexities (e.g., unconsolidated sand, excess volume of gas, or casing size), or lack of an adequate injection zone within the subject well. In those instances, alternative treatment and disposal is required.
The present application relates to a surface separation system used to separate fluids such as oil, gas, water, and/or sand slurry produced from a well. The separation system may include a pumping system, such as a horizontal pumping system (HPS), a separator, and flow control hardware. The separator system may be mounted on a skid or incorporated directly into a production flow. The separator system may be used in conjunction and/or in parallel with a conventional surface separation facility.
Other aspects and advantages will become apparent from the following description and the attached claims.
It is to be understood that the drawings are to be used for the purpose of illustration only, and not as a definition of the metes and bounds of the invention, the scope of which is to be determined only by the scope of the appended claims.
Specific embodiments of the invention will now be described with reference to the figures. Like elements in the various figures will be referenced with like numbers for consistency. In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without many of these details and that numerous variations or modifications from the described embodiments are possible. As used here, the terms “above” and “below”; “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship as appropriate.
HPS 10 can be coupled to a separator 24, as shown in
As stated, there are multiple ways of configuring a separation system. For example, it may be configured to operate in a “brown field” application.
Separator skid 28, as shown in
As further shown in
The separated water is discharged from discharge manifold 30 at the separator water discharge pressure, PW, and passes through water choke 34 into intake 16 of HPS 10. Pressure is provided to the water by pump 18 and the water leaves discharge 20 at the injection well surface pressure, PIS. The pressure, PI, of the water when delivered to injection zone 40 is the sum of the injection well surface pressure and the hydrostatic pressure of the water column, less any pressure losses occurring along the length of the transport tubing.
The well head pressure must be sufficient to overcome various pressure drops that may be experienced by the produced fluids. The pressure drops may occur, for example, due to the action of separator 24, the passage of fluids through discharge manifold 30, passing through oil or water chokes 32, 34 (e.g., PO>PTH), agency-regulated requirements for water boost pumps, or, for the oil phase, field flow line pressure. For example, the separator water discharge pressure, PW, is required by current regulation to be greater than or equal to 30 psi. Thus, the well head pressure must be high enough so that the encountered pressure drops do not reduce the separator water discharge pressure below 30 psi unless auxiliary pressure boosters are provided.
An alternate embodiment uses a single disposal well 46, as shown in
Oil tapped from the field lines and routed to separator unit 48 is passed to separator 24, or, optionally, fed to a boost pump 50 before being passed to separator 24. Separated oil passes from discharge manifold 30 through oil choke 32 and is returned to the field lines. Separated water passes from discharge manifold 30 through water choke 34 and into intake 16 of HPS 10. The water is pumped under pressure through discharge 20 and into disposal well 46.
Similarly, a separator unit 48 or separator skid 28 may be located near a tank battery (not shown) instead of a disposal well 46. Oil from the field lines or tanks is processed as described above and the separated oil is returned to the field lines or tanks. The separated water is discharged into a field-wide injection flow system. This would likely require an additional injection pump be located at the well site. The separator skid 28 or separator unit 48 could remove some of the loading from the existing battery facilities.
A separation skid 28 may also be used in parallel or in conjunction with conventional surface separation or treatment facilities, as shown in
Similarly, as shown in
A separation skid 28 may also be deployed in conjunction with a surface separation facility 52 to enhance or accelerate produced water treatment, as shown in
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be envisioned that do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention shall be limited only by the attached claims.
This application claims priority to and the benefit of U.S. Provisional Application Ser. No. 61/150841, filed on Feb. 9, 2009.
Number | Date | Country | |
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61150841 | Feb 2009 | US |