Patent Application
20100212881
The subject invention relates generally to an apparatus for controlling a well on a rig or platform.
In the course of drilling, completing, and producing subterranean reservoirs, operators find it necessary to rig up and run into a well various types of work strings. Examples of work strings include, but are not limited to, drill strings, coiled tubing, snubbing pipe, electric line, production tubing, and wireline.
When working with subterranean reservoirs, operators are always concerned about the high pressure that may exist in such reservoirs. These high pressures may reach several thousands of pounds per square inch. Thus, during any type of operation involving work strings that are run into a well, operators will employ various types of valves at the surface of the well to isolate the crew members working on the well from the high pressure within the reservoir.
The present invention is a well surface control system for use with various types of work strings such as, but not limited to, drill strings, coiled tubing, snubbing pipe, electric line, production tubing, and wireline. The preferred embodiment of the present invention includes a main housing having a longitudinal axis, an outer wall, a first end, and a second end. A main bore extends through the main housing along the longitudinal axis from the first end to the second end of the main housing. The main housing is equipped with a side port through the outer wall of the main housing in communication with the main bore between the first end and the second end of the main housing. The main housing is also equipped with two valves for controlling fluid and/or gas flows through the main bore and for severing components of a work string running through the main bore. The first valve is positioned between the side port and the first end of the main housing and the second valve is positioned between the side port and the second end of the main housing. Attached to each end of the main housing is a saver sub, with means for temporarily locking the saver subs to the main housing to prevent circular and longitudinal movement of the saver subs in relation to the main housing.
An advantage of the present invention is that it provides a single, compact system for controlling pressure in a well and for severing components of a work string. Another advantage of the present invention is that it provides a locking mechanism to keep crossovers securely connected to the system in a derrick of a rig. Still another advantage of the present invention is that it can be quickly and easily connected to any type work string. Yet another advantage of the present invention is that it provides a faster rig-up and rig-down time than conventional blow out preventers.
The accompanying drawings are provided for the purpose of illustration only and are not intended as a definition of the limits of the present invention. The drawings illustrate a preferred embodiment of the present invention, wherein:
While the present invention will be described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments (and legal equivalents thereof) falling within the scope of the appended claims.
A preferred embodiment of the present invention is shown in
Main housing 20 is preferably equipped with a side port 30 through outer wall 25, which can serve as an inlet or outlet for fluids flowing through main bore 24 into or out of a well. Side port 30 can be equipped with a flange interface 31, as shown in
Side port 30 can be connected to a tank for receiving fluids and/or gas exiting the well, or connected to a pump for introducing fluids, such as a kill fluid, into the well for controlling the pressure of the reservoir inside the well. As understood by those of ordinary skill in the art, the hydrostatic head of the fluid introduced into the well suppresses reservoir pressure and, thus, the term “kill fluid” is used in this context.
As shown in
First valve 40 and second valve 50 are preferably M&M Canister Guard ball valves commercially available from M&M International, as disclosed in U.S. Pat. No. 5,246,203 assigned to M&M Supply Co. (incorporated herein by reference). It should be understood that any valves that perform the functions of controlling fluid flow through main bore 24 and severing components of a work string 101 running through main bore 24 are acceptable for purposes of the preferred embodiment of the present invention.
Referring to
The valve mechanisms of first valve 40 and second valve 50 can be manipulated either manually or mechanically. In either case, the valves are opened or closed by turning valve stems 42 and 52. One method of mechanically manipulating the valve mechanisms of first valve 40 and second valve 50 is by hydraulic control means, as understood by those of ordinary skill in the art.
In the preferred embodiment, first end 22 has a threaded drill pipe box 26, as shown in
Likewise, in the preferred embodiment, second end 23 has a threaded drill pipe box 27, as shown in
In the preferred embodiment of the present invention, first saver sub 60 has a female end 64 with a threaded drill pipe box 65. A first crossover sub 80 having a male end 81 with a threaded drill pipe pin 82 can be connected to female end 64 of first saver sub 60. Different first crossover subs 80 having a second end 83 that can vary in size can be connected to first saver sub 60 to accommodate different work strings, such as, for example, but not by way of limitation, a 7″ 29# Hydril 563 Box, or a 5½″ 20# VAM Top HC Box, or a 6″ 30.9# VAM Top HC KA Box, or a 5⅞″ XT-M57 Box, or the like.
In the preferred embodiment of the present invention, second saver sub 70 has a female end 74 with a threaded drill pipe box 75. A second crossover sub 90 having a male end 91 with a threaded drill pipe pin 92 can be connected to female end 74 of second saver sub 70. Different second crossover subs 90 having a second end 93 that can vary in size can be connected to second saver sub 70 to accommodate different work strings, such as, for example, but not by way of limitation, a 7″ 29# Hydril 563 Pin, or a 5½″ 20# VAM Top HC Pin, or a 6″ 30.9# VAM Top FTC KA Pin, or a 5⅞″ XT-M57 Pin, or the like.
In the open position, first valve 40 and second valve 50 allow fluid flow through main bore 24 (and through side port 30, if desirable) in either the up hole or down hole scenario. In addition, while in the open position, first valve 40 and second valve 50 allow operators to raise or lower various types of work strings, such as, for example, drill strings, coiled tubing, snubbing pipe, electric line, production tubing, and wireline, through well surface control system 10, as is readily understood by those of ordinary skill in the art.
Referring now to
During well intervention work, when first valve 40 and second valve 50 are in the open position, there are occasions when high-pressure fluid will begin to flow up the well. On these occasions, well surface control system 10 can control the pressure and flow of fluid from within the well by closing second valve 50 and first valve 40. These valves can be actuated either hydraulically, remotely, mechanically, pneumatically, or electronically. In the preferred embodiment, particularly during wireline operations, the closing of first valve 40 and second valve 50 will sever the wireline or other components of a work string, which avoids having to remove the wireline or work string from the well before closing first valve 40 and second valve 50.
During producing and pumping stages, well surface control system 10 can be used to release pressure from within the well by closing first valve 40 and opening second valve 50 and valve 32 to release pressure into a tank (not shown). As readily understood by those of ordinary skill in the all, the operator may also choose to pump fluids into the well through valve 32 and second valve 50 (while first valve 40 is closed). The operator can pump a fluid, such as a weighted fluid, to control the pressure in the well. The weighted fluid is sometimes referred to as a kill fluid. Once the well pressure is under control by the operator, first valve 40 can be opened, after which a work string, such as a coiled tubing, can then be concentrically lowered through well surface control system 10 and the tubular string 105, thereby allowing operations can continue.
Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of construction and operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
