US 3193016 A
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Description (OCR text may contain errors)
July 6, 1965 G- s. KNOX REVERSE FLOW TUBING VALVE Filed April 30, 1962 INVENTOR Gemvwus 5. H/vox flrrafllvEYs.
United States Patent M 3,193,016 REVERSE FLOW TUBING VALVE Granville S. Knox, Glendale, Califi, assignor to Hydril Company, Los Angeles, Calif., a corporation of fihio Filed Apr. 30, 1962, Ser. No. 190,891 8 Claims. (1. 166-4134) This invention relates generally to oil well tubing string valves, and more particularly concerns valves for controlling so called reverse circulation of fluid into tubing strings at points above packers sealing off between the tubing string and well casing.
In operating oil wells it is sometimes desired to initiate and establish fluid flow into the tubing from the annular space surrounding the tubing and above a packer. As an example, it may be desired to lighten the liquid column by injecting gas into the tubing. Other examples of such reverse circulation include the injection of corrosion inhibitors or paraflin dissolving solutions into the curde flowing upward in the tubing. Past methods of establishing and controlling such reverse circulation have not been found entirely satisfactory for various reasons, including the complexity and bulk of actuator devices, operating mechanically or hydraulically, these being capable of malfunction and also occupying space in the tubing string which would otherwise be more fully open to pass the crude oil flow.
The present invention contemplates the provision of an extremely simple reverse flow oil well tubing valve, characterized as having a novel construction making the valve responsive to exterior fluid pressure to establish the desired reverse circulation. As broadly conceived, the valve includes a tubular body connectible into a tubing string, the body having at least one flow port, a pressure responsive sleeve movable longitudinally of the body between an open or unseated position and a closed or seated position to control reverse circulation of fluid therethrough, and yieldable means acting to transmit force urging the sleeve to closed position in which the sleeve prevents reverse circulation through the port.
As will be brought out, the valve elements are further characterized as functioning to cause the sleeve to remain in closed position until the exterior fluid pressure exceeds the fluid (crude) pressure inside the tubing, by a predetermined value, the sleeve being provided with external and internal shoulders and spring biasing means being used to achieve this result. Also, .the sleeve and body elements cooperate in such a way as to provide a drop in the pressure of exterior fluid as it passes over the valve seat to the port upon opening movement of the sleeve, thereby to prevent premature re-closure of the sleeve immediately after opening thereof to establish reverse circulation.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following detailed description of the drawing, in which:
FIG. 1 is a vertical elevation taken through the valve shown as connected in a tubing string in a well, the valve being in closed condition;
FIG. 2 is a section taken on line 2-2 of FIG. 1; and
FIG. 3 is a fragmentary elevation showing the valve in open condition.
The tubing string is shown at extending downwardly within a well formation 11, and typically within well casing 12. Means packing off between the tubing and the casing in the well is generally indicated at 13, and the valve means is shown at 14 as being connected into the string in the well above the level of the packer, for controlling reverse circulation of fluid from the exterior 15 to the interior 16 of the valve means.
The latter includes a longitudinally extending tubular 3 ,1 93 l 6 Patented July 6, 1965 body typically represented by the body part 17 and coupler 13 screwed onto the part 17 at 19, the coupler also being thread connected at 20 to the upper stand 21 of tubing. The valve body has at least one flow port, and typically a series of such ports as are represented at 22, these being arranged in circularly spaced relation and communication with the body bore.
The valve assembly also includes a pressure responsive annular sleeve generally indicated at 23 which is movable longitudinally of the body between unsea-ted open position and a seated closed position to control reverse circulation of fluid through side ports 22. While the sleeve is shown as being outside the body 17, it may alternatively be located within the body, so long as its functioning remains the same 'as described herein. The sleeve is urged toward seated position as shown in FIG. 1 by yieldable means, typically comprising a spring 24, and the sleeve in seated position prevents reverse circulation through the ports 22. The opposite ends of the spring 24 are compressed between the enlarged portion 25 of the tubular body and the terminal 26 of the sleeve exterior to the body. It will also be noted that longitudinal movement of the sleeve is guided by slide fit interengagement of the sleeve bore 27 with the cylindrical periphery 28 of the flange 29 on the valve body. A suitable seal is provided at 30 to seal off between the flange 29 and the sleeve bore 27.
The sleeve has a first shoulder 31 located to remain continuously exposed to the exterior 15 so as to remain sensitive to application of exterior fluid pressure thereon opposing the spring force so that sufficient exterior pressure moves the sleeve downward to open position as shown in FIG. 3, thereby to establish the desired reverse circulation as indicated by the arrows 32. In addition the sleeve has a second shoulder 33 located to be exposed to the tubing interior 16 through the ports 22, so as t be sensitive to application of interior fluid pressure therein aiding the spring means force. In this regard, it will be observed that the pressure receiving areas of the shoulders 31 and 33 are predetermined in such a way that the sleeve remains in closed position until the exterior pressure exceeds the interior pressure by a predetermined value. Generally speaking, the effective area of the shoulder 33 will be approximately equal to the effective area of the shoulder 31 and the external pressure applied to the shoulder 31 for opening the sleeve valve must overcome the spring force plus the internal pressure applied to the shoulder 33.
The tubular body also includes an annular seal typically made of molded tetrafluoroethylene and indicated at 34, which is engageable by an annular seat 35 on the sleeve in closed position thereof. The tubular body also has an annular stop 36 engageable by the sleeve shoulder 33 to determine the open position of the sleeve as shown in FIG. 3. As is clear from these figures, the shoulder 33 and the stop 36 are annular and face endwise oppositely, annular space 37 being formed therebetween in direct communication with the ports 22.
The sleeve has an annular interior flange 38 which projects between the seal 34 and the tubular body stop 36, the seat 35 and the shoulder 33 being found at opposite ends of the flange. A relatively restricted upwardly tapering flow passage 39 is formed between the flange bore and the tubular body at the interior pressure side of the seat 35. The purpose of this clearance is to provide a drop in pressure of exterior fluid flow after it passes between seat 35 and seal 34 and before reaching the ports 22, upon opening movement of the sleeve. Thus, the unseated sleeve and body form a sufficiently reduced flow passage or clearance in the path of the reverse circulation between said seat and seal, and port 22, that the pressure of reversely circulating fluid is reduced upon flowing through said flow passage, whereby only the reduced pressure of the reversely circulating fluid can reach the shoulder 33. More specifically, the desired drop in pressure prevents rapid premature reclosure of the sleeve, after partial opening thereof, which would otherwise be brought about by application of full or undirninished exterior fluid pressure upwardly against the shoulder 33.
Accordingly, when the sleeve opens the construction is nular and face longitudinally oppositely, and in which annular space is formed therebetween in direct communication with said port in said sleeve seated position. I
5. Valve means connectible into a tubing string extending longitudinally downwardly in well casing and operable to control reversecirculation to fluid from the exterior to the interior of said valverneans, said valve means such as to cause the sleeve to rnove'further toward'the fully open position without tendency to chatter.
From the foregoing it will' be' seen that the valve is constructed for specific use in oil well tubing not only in the respects previously described but also in the. respect that the valve does not diminish the internal bore.
v diameter 4% of the tubing and of the valve body 14,. In addition, the moving parts of the valve lie within the cylindrical loci defined by the outer. periphery 41 of the valve body, and by the bore 40. a
I claim: 1. In combination, a tubing dinally downwardly in well casing, first means packing string extending longitu ed between the tubing and the casing in the well, and valve means connectedinto the spring in the well above 7 a the level of said first means for controlling reverse circulation of fluid from the exterior to the interior of said valve means, said valve means including a longitudinally extending tubular body having at least one flow port through the body side, a pressure responsive annular sleeve movable longitudinally of the bodyi between unseated and):
seated positions to control reverse circulation of fluid through the port, and yieldablemeans acting to transmit force urging the sleeve to said seated position, said sleeve comprising a longitudinally extending tubular body having at least one flow'port thro gh thebody side, a pressure responsive annular sleeve movable longitudinally of the body'betwe'en'unseated and seated positions to control reverse circulation of fluid through the port, and spring means acting to transmit force urging the sleeve to said,
seated position, said sleeve having a first'shoulder located to remain continuously exposed to the sleeve and tub- 4 ing exteriorso as to remain sensitiveto application of exterior fluid pressure thereon opposing said spring means force whereby suflicient exterior pressure moves the sleeve to unseatedv positionto establish said reverse circulation, the sleeve also having a second shoulder located for exposure through said port to. the pressure of fluid within said tubular body thereby aidingthe force transmitting 1 action of said spring means, the tubular bodyvand sleeve having annular surfaces which are engaged in said sleeve seated position to prevent circulation through said port,
the unseated sleeve'and saidbody' forming a sufliciently 2 reduced flow passage in the path of said reverse circulahaving a first shoulderlocated to remain continuously exposed to the sleeve and tubing exterior so as to remain sensitive to application of exterior fluid pressure thereon opposing said'yieldable means force whereby sufilcient exterior pressure moves the sleeve to unseated positionto a second shoulder located for exposure through said port to the pressure of fluid within said tubular body thereby aiding the force transmitting action of said yieldable means, the tubular body and sleeve having annularsur faces which are engaged in said sleeve sea'ted p-osition to prevent circulati-on through said port, the unseated sleeve and said body forming a sufliciently reduced flow passage in the path of said reverse circulation between said disengaged surfaces and' said port and in all unseated positions of the sleeve so that the pressure of reversely circulafing fluid .is reduced upon flowing through said passagewhereby only the reduced pressure of the reversely ci1 culating fluid can reach said second shoulder, the body and 'sleeve having slidable annular sealinginterengagernent in: spaced relation: to said surfaces and port. 7 V 2."The invention as defined in claim 1 in which the tubular body includes an annular plastic sealengageable' by the sleeve in seated pos'tion. v t 3. The invention as defined in claim 2 in which the tubular body has a stop engageable by the sleeve second shoulder to determine a fully open position of the sleeve.
establish saidreverse circulation,'the sleeve'also having 4 faces. and port. 7
tion between said disengaged surfaces and said port and in all unseated positions of the sleeve sothat the pressure of reversely circulating fluid is reduced upon flowing through said passagewhereby only the reduced pressure of thejreversely circulating fluid can reach said second shoulder, the body and sleeve having slidable annular sealing interengagement in spaced relation to said sur- 6. The, invention as defined .in claim in which the tubular body includes an annular plastic seal engage- "I able by the sleeve. in seated position, said sleeve being 7 outside saidtubular body.
7. The invention as defined in claim 5 in which the V tublar body has a stop engageable by the sleevesecond shoulder to determine a fully open position of the sleeve. 8. The invention as definedin claim 7 inwhich said sleeve second shoulder and tubular'body stop are annular andface longitudinally oppositely and which annular.
. space is formed therebetween in direct communication so 7 4. The invention" as defined in claims in whichjsaid sleeve second shoulder and tubular body stopare an- 7 withfsaid port in said sleeve seated position.
BENJAMIN nERsn, Primary Examiner. CHARLES OCCN NELL Examiner;