US3897825A

US3897825A - Well testing apparatus

Info

Publication number: US3897825A
Application number: US468834A
Authority: US
Inventors: Gilbert H Tausch
Original assignee: Camco Inc
Current assignee: Camco International Inc
Priority date: 1974-05-15
Filing date: 1974-05-15
Publication date: 1975-08-05
Anticipated expiration: 1992-08-05
Also published as: GB1461893A

Abstract

An apparatus for use in testing conditions in a well bore during and subsequent to drilling while simultaneously providing blowout protection. A well testing apparatus for use in a well having a casing and a blowout preventer. A well conduit is provided adapted to be positioned inside the casing and extending above and below the blowout preventer whereby the blowout preventer may close upon the exterior of the conduit and an annulus is provided between the exterior of the conduit and the interior of the casing. A safety valve is connected in the conduit below the blowout preventer and is biased to a closed position by a closed pressure chamber thereby allowing the safety valve to be utilized at greater depths. The pressure in the annulus is controlled from the surface for opening the valve thereby controlling the actuation of the valve from the surface by the annulus pressure. A circulating valve is positioned in the conduit above the safety valve for providing communication between the annulus and the interior of the conduit. One or more landing nipples are provided in the conduit for supporting test equipment and/or conduit closing means.

Description

United States Patent [191 Tausch 1 1 WELL TESTING APPARATUS [75] Inventor: Gilbert H. Tausch, Houston. Tex,

[73] Assignee: Cameo. Incorporated, Houston. Tex.

[22] Filed: May 15.1974

[21] Appl. No; 468,834

[52] U.S. Cl 166/224 A; 137/496; 166/226 [51] lnt.Cl." E218 43/12 [58] Field of Search 166/224 A, 166. 226. 86. 166/217; 137/496 [56] References Cited UNITED STATES PATENTS 3,US(L12U 3/1962 McSpadden 166/86 3.071.193 1/1963 Raulins 166/224 3.074.485 1/1963 McGowcn. .lr, 166/217 3.200.837 8/1965 Brown 137/496 3.315.747 4/1967 Farley et al.. 166/226 3.494.419 2/1970 Mullins 166/226 Primary Examiner-James A, Leppink Attorney, Agent. or Firm-Fulbright & .laworski 1 1 Aug. 5, 1975 57] ABSTRACT An apparatus for use in testing conditions in a well bore during and subsequent to drilling while simultaneously providing blowout protection. A well testing apparatus for use in a well having a casing and a blowout preventer. A well conduit is provided adapted to be positioned inside the casing and extending above and below the blowout preventer whereby the blowout preventer may close upon the exterior of the conduit and an annulus is provided between the exterior of the conduit and the interior of the casing. A safety valve is connected in the conduit below the blowout preventer and is biased to a closed position by a closed pressure chamber thereby allowing the safety valve to be utilized at greater depths. The pressure in the annulus is controlled from the surface for opening the valve thereby controlling the actuation of the valve from the surface by the annulus pressure. A circulating valve is positioned in the conduit above the safety valve for providing communication between the annulus and the interior of the conduit. One or more landing nipples are provided in the conduit for supporting test equipment and/or conduit closing means.

4 Claims. 5 Drawing Figures SHEET PATENTED AUG 5W5 lll WELL TESTING APPARATUS BACKGROUND OF THE INVENTION It is old to use a safety valve in a flow connector in drilling operations positioned below a blowout preventer as shown in US. Reissue Pat. No. 27.471 and controlled from the water surface. However, the drilling depths have steadily been increasing and it is therefore necessary to provide equipment which will overcome the problems encountered at greater depths as well as improving apparatus for use in shallower depths. The present invention provides various improvements to a well testing apparatus by controlling a safety valve in the testing apparatus from the well sur face by the use of an annulus between the well conduit and the casing thereby avoiding the requirement of an extra control line leading from the water surface to the safety valve. The present invention is also directed to a safety valve which is biased to the closed position by a charged gas chamber thereby allowing the safety valve to be operated at greater depths than safety valves normally biased by springs. The present testing apparatus utilizes a circulating valve and landing nipples to provide a system which is versatile in testing while simultaneously providing safety protection against well blowout.

SUMMARY The present invention is directed to a well testing apparatus for use in a well having a casing and a blowout preventer for providing various testing facilities as well as providing blowout protection. A well conduit is provided which is adapted to be positioned inside of the casing and extend above the blowout preventer to the surface and extend below the blowout preventer for normal drilling or testing operations. The blowout preventer may close upon the exterior of the conduit and an annulus is provided between the exterior of the conduit and the interior of the casing.

Blowout protection through the conduit is obtained by providing a safety valve connected in the conduit below the blowout preventer in which the safety valve is controlled from the surface by controlling the pressure in the annulus and in which the safety valve is biased to a closed position by a closed and charged pressure chamber thereby allowing the safety valve to oper ate at greater depths.

A still further object of the present invention is the provision of a circulating valve connected in the conduit above the safety valve for circulating fluid between the interior and the exterior of the conduit when desired.

Yet a still further object of the present invention is the provision of a landing nipple in the conduit positioned below the safety valve for supporting various types of testing equipment such as pressure recording instruments and the like.

Still a further object of the present invention is the provision of a landing nipple in the conduit positioned above the safety valve which may be used for supporting various equipment such as a conduit plug for securely closing the interior of the conduit which is useful in the event that the drilling rig moves off of location for any reason such as storms.

Other and further objects, features and advantages will be apparent from the following description of a presently preferred embodiment of the invention, given for the purpose of disclosure and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view in perspective. and partly in cross section. illustrating the apparatus of the present invention in use.

FIG. 2 is an enlarged elevational view. partly in cross section, illustrating a portion of the well conduit including a circulating valve and a top portion of a landing nipple.

FIG. 3A is an enlarged elevational view. partly in cross section, and is a continuation of the well conduit of FIG. 2 illustrating the lower portion of the landing nipple and a portion of the safety valve.

FIG. 3B is an elevational view. partly in cross section. and is a continuation of FIG. 3A illustrating the middle portion of the safety valve, and

FIG. 3C is an elevational view, partly in cross section. and a continuation of FIG. 3B illustrating the lower portion of the safety valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to FIG. 1, the reference numeral 10 generally indicates the well testing apparatus of the present invention in which a well is drilled beneath the water surface 12 on the water floor 14 such as by a drilling rig l6. The well includes the usual support structure 18, conventional blowout preventer 20 and casing 22 extending downwardly in the well bore.

The present invention is directed to providing a testing and safety apparatus which includes a well conduit 24 such as a drilling string extending from the water surface 12 and the drilling rig 16 through the blowout preventer 20 and casing 22 to form an annulus 26 with the casing 22. A packer 28 may be positioned in the annulus 26 between the conduit 10 and the casing 22. The blowout preventer 20 may be conventionally actuated to close on the exterior of the well conduit 24 for closing off the top of the annulus 26 either for testing purposes or for safety purposes. The blowout preventer 20 includes a line 30 extending to the drilling rig I6 and in communication with the annulus 26 through which a fluid may be transmitted for increasing or decreasing the pressure in the annulus 26 for controlling a safety valve. as will be more fully described hereinafter.

While the conduit 24 may be supported from the drilling rig 16, the conduit 24 may also be supported from the underwater well installation by the blowout preventer 20, which is particularly desirable in the event that the floating drilling rig 16 may be required to move from the location for various reasons including inclement weather.

The well conduit includes a circulating valve 32, a safety valve 34, and one or

more landing nipples

36 and 38. After well drilling operations have been performed. and it is desired to test the well. the well conduit 24 including the circulating valve 32, safety valve 34 and

landing nipples

36 and 38 are lowered into the well installation. and the blowout preventer is actuated to engage the outer periphery of the well conduit 24 to hold it in place and also seal the upper end of the annulus 26. The usual and conventional well testing may be accomplished such as production testing by allowing well production to flow up the well conduit 24 to the drilling rig 16. Other suitable tests may be performed, such measuring the pressure in the well by installing a conventional pressure recording instrument in the landing nipple 38. The circulating valve 32 includes an opening 33 communicating between the interior of the conduit 24 and the annulus 26 which may be opened by conventional wireline operations, such as after a drill stem test, to flow drilling mud therethrough.

While, of course, the blowout preventer closes off the top of the annulus 26 and provides blowout prevention through the annulus 26, it is also important that blowout prevention be provided inside of the well conduit 24. Since the drilling of wells underwater has been increasing at a rapid pace and at greater depths in an effort to obtain oil, it is important that the safety valve 24 be able to simply and efficiently close off the interior of the conduit 24 at the greater depths than generally encountered in the past and at the still further depths expected to be encountered in the future. The safety valve of the present invention utilizes a biasing force of a closed pressure chamber for biasing the safety valve to the closed position similar to that shown in U.S. Pat. No. 3,782,461 which allows the safety valve 34 to be installed at greater depths and yet obtain a sufficient biasing pressure to overcome the hydrostatic head in the annulus 26 attempting to open the valve. The safety value 34 is actuated to an open position through a port 40 in communication with the annulus 26 for controlling the operation of the safety valve through the line to the blowout preventer 20 thereby avoiding the undesirable necessity of providing an extra fluid conduit for controlling the actuation of the safety valve 34.

Referring now to FIG. 2, the circulating valve 32 may be of any suitable type such as the type C sliding sleeve valve of Cameo, Incorporated. The valve 32 includes a sliding sleeve 42 having an opening 44 which when in registry with the port 33 allows communication be tween the interior of the conduit 24 and the annulus 26. The sleeve 42 includes

annular grooves

46 and 48 for releasably holding the sleeve 42 in either the open or closed position when the grooves are alternately engaged with an annular shoulder 50 on the body 52 of the valve 32. The sleeve 42 is conventionally actuated such as by wireline tools which conventionally engages and moves the sleeve to an upward or downward position.

Referring to FIGS. 2 and 3, landing nipple 36 is shown. such as a Cameo Type W nipple. The landing nipple 36 includes an annular recess 54 for supporting a conventional well lock such as the Cameo Type M lock for supporting any desired testing or safety equipment in the landing nipple 36. For example, a conventional plug may be attached to the well lock and inserted in the landing nipple 36 for closing off the interior passageway of the well conduit 24, in addition to or as an alternative to the safety valve 36, which may be desirable in the event that the drilling rig 16 moves away from the well installationv The landing nipple 38, shown in FIG. I, may be similar to the landing nipple 36 and may be used for supporting any suitable testing or safety equipment from the interior of the conduit 24 by a well lock as previously described.

Referring now to FIGS. 3A, 3B and 3C, a suitable the seat 60, the safety valve 34 is closed blocking flow upwardly therethrough. A sliding tube 68 is telescopically movable in the body 64 and through the valve seat 60. When the tube 68 is in the downward position, as best seen in FIG. 3C, the tube 68 pushes the flapper 62 away from the seat 60 and holds the valve in the open position. When the tube 68 is moved upwardly. the flapper 62 is allowed to move inwardly closing the valve.

As best seen in FIGS. 3A and 3B, a chamber is provided between the sliding tube 68 and the body 64 and a piston 72 is secured to the tube 68 which is movable in the chamber 70. The chamber 70 below the piston 72 is pressurized to a desired pressure with gas through a dill valve 74. The pressure in the pressurized chamber 70 acts against the bottom of the piston 72 in a direction to move the sliding tube 68 upwardly to allow the flapper 62 to close and seat. If desired, the closing force may be assisted by a spring 76 which acts on the sliding tube 68. However, the pressurized chamber provides a greater amount of biasing force than can conveniently be obtained from a biasing spring 76 and is therefore particularly useful for greater depths in overcoming the hydrostatic head in the annulus 26 acting to open the valve.

The safety valve 34 is controlled by the application or removal of pressures through the port 40 into a chamber 76 against the top of the piston 72 acting in opposition to the force of the pressure in the chamber 70 and the spring 76. Thus, if pressure is applied through the port 40 from the annulus 26 of sufficient magnitude, the piston 72 and thus the tube 68 is moved downwardly forcing the flapper 62 off of the seat and into the full open position. If the pressure in the annu lus is reduced sufficiently relative to the forces acting on the piston biasing the valve to a closed position, the sleeve 68 will be moved upwardly allowing the valve to close. It is to be noted that the safety valve 34 is actuated by the pressure in the annulus 26 which is supplied by the conventional line 30 to the blowout preventer 20 thereby avoiding the requirement of having an additional control line leading from the water surface to the safety valve 34 which is particularly undesirable at deep drilling depths.

The present invention, 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 the purpose of disclosure, numerous changes in the details of construction and arrangement of parts may be made without departing from the spirit of the invention and the scope of the appended claims.

What is claimed is:

l. A well testing apparatus for use in a well having a casing and a blowout preventer comprising,

a well conduit adapted to be positioned inside the casing and extend above and below the blowout preventer whereby the preventer may close on the exterior of the conduit and an annulus is provided between the exterior of the conduit and the interior of the casing,

a control passageway leading from the annulus to the well surface for controlling the pressure in the annulus,

for controlling the actuation of the valve by pressure in the annulus and control passageway, and

a landing nipple in the conduit for supporting additional equipment in the conduit.

2. The apparatus of claim 1 wherein the landing nipple is positioned above the safety valve.

3. The apparatus of claim 1 wherein the landing nipple is positioned below the safety valve.

4. The apparatus of claim I wherein the landing nip- 10 ple is positioned above the safety valve. and a second landing nipple is positioned below the safety valve.

Claims

1. A well testing apparatus for use in a well having a casing and a blowout preventer comprising, a well conduit adapted to be positioned inside the casing and extend above and below the blowout preventer whereby the preventer may close on the exterior of the conduit and an annulus is provided between the exterior of the conduit and the interior of the casing, a control passageway leading from the annulus to the well surface for controlling the pressure in the annulus, a circulating valve connected in the conduit for opening and closing communication between the interior and the exterior of the conduit, a safety valve connected in the conduit below the circulating valve, said safety valve controlling fluid flow through the conduit, and including, a valve closure member moving between open and closed positions and actuated by piston means, a closed pressure chamber acting on the piston means for biasing the valve to a closed position, a control port exposed to the annulus and acting on the piston means in a direction to open the valve for controlling the actuation of the valve by pressure in the annulus and control passageway, and a landing nipple in the conduit for supporting additional equipment in the conduit.

4. THe apparatus of claim 1 wherein the landing nipple is positioned above the safety valve, and a second landing nipple is positioned below the safety valve.