US3497009A - Circulating tool - Google Patents

Description

Feb. 24, 1970 J. w. HARRINGTON C IRCULAT ING TOOL Filed Jan. 15, 1969 dme-U W Har/fag fon INVENTOR- BY Mami/nf, l m ,fw

Afro/PMS VJ United States Patent Gf'fce 3,497,009 Patented Feb. 24, 1979 U.S. Cl. 166--226 3 Claims ABSTRACT F THE DISCLOSURE The tool includes two telescoping tubular members for installation in a pipe string. The two members are connected together by screw threads so that relative rotation of the members will move one of the members axially of the other. One member is provided with lateral openings through which the fluid in the well bore can flow into and out of the tool and the pipe string, when the tool is in its open position. The other member closes off the lateral openings, when the tool is in its closed position. The tool is opened by unscrewing the two members. Engaging annular shoulders on the two members limit the distance the members can telescope. One of the shoulders is grooved to reduce the frictional force between the shoulders when the tool is closed and the shoulders are in engagement to reduce the torque required to open the tool.

This is a continuation-in-part of patent application Ser. No. 585,006, filed Oct. 7, 1966, entitled Pipe String Fill- Up Tool, now abandoned, and patent application Ser. No. 653,292, filed June 22, 1967, entitled Pipe String FillJUp Tool.

This invention relates to circulating tool apparatus for use in a well bore in conjunction with a tubular string disposed therein.

While performing operations in a well bore, it is desirable to have a valve in the pipe string that can be opened to permit fluid to be circulated between the interior of the pipe string and the exterior thereof and which then can be closed when such circulation is not desired. For example, during fishing operations, when an overshot or spear of the pack olf type is employed, it is often impossible to establish circulation through the fish after the spear or overshot has engaged the fish. Fishing operations can continue without circulation for a while, but there comes a time, particularly when fishing in an open hole, when it is desirable, if not necessary, to circulate the well for a while to make sure the drilling fluid and hole remain in the best possible condition. Without a circulating valve above the fishing tool, the spear or overshot would have to be released from the fish in order to circulate the hole. This is undesirable because it is never known whether or not the fish can be re-engaged by the fishing tool once it is released therefrom.

Therefore, it is an object of this invention to provide a circulating tool for a pipe string that can be opened and closed from the surface simply by rotating the pipe string.

It is a further object of this invention to provide a circulating tool that can be `subjected to large tensile stresses, when closed, as well as stress reversals and impact forces, such as those imposed on a drill string during fishing operations, particularly when jars are employed to impart large impact forces on the fish.

It is a further object of this invention to provide a circulating tool that employs a threaded connection that is made up when the tool is closed and which is broken and partially unscrewed to open the tool wherein the connection employed is so arranged that the force required to break the connection is less than that required to break the other threaded connections in the pipe string to insure that the other threaded connections are not inadvertently broken and unscrewed when the circulating tool is being opened.

These and other objects, advantages, and features of the invention will be apparent to those skilled in the art from a consideration of this specification, attached drawings, and appended claims.

By way of example, but not limitation, the preferred embodiment of the invention will now be described in connection with the attached drawings, in which:

FIGURE l is a view, partially in elevation and partially in vertical section, of the preferred embodiment of the circulating tool of this invention in the closed position;

FIGURE 2 is a view, partly in vertical section and partly in elevation, of the circulating tool of FIGURE 1 in the open position; and

FIGURE 3 is a cross sectional view taken along line 3-3 of FIGURE 2.

The circulating tool includes two telescoping members, first member or mandrel 10 and second member or housing 11. The mandrel is adapted to be connected to the upper portion of the pipe string (not shown). Housing 11 is connected to the lower portion of the pipe string (not shown) by sub 12.

Means are provided to connect the first and second members together and for moving the members from a first position to a second position, when the members are rotated relatively in one sense. In the embodiment shown, mandrel 10 is provided with externally threaded section 13. Housing 11 is provided with internally threaded section 14. These threaded sections combine to provide a threaded connection between the two members that will move the rst member axially into the second member, when the members are rotated relatively in a given sense and that will move the first member axially out of the second member when they are rotated relatively in the other sense. Where the drill pipe is made up of tool joints having right-hand threads, the threaded connection ernployed in the tool should also be right-hand.

Section 11a of the bore of the housing below threaded section 14 is covered with a layer of hard, wear resistant material such as tungsten carbide. Preferably, the clearance between bore section 11a and tubular section 10a of the mandrel is a minimum, compatible with the members moving relatively with ease. This is desirable because it adds lateral stability to the tool, which is particularly important when the tool is in the closed position and subjected to impact loading.

A plurality of lateral openings 21 extend through the wall of housing 11 below bore section 11a. It is through these openings that uids can pass between the inside and outside of the pipe strings, when the tool is open as shown in FIGURE 2. Preferably, these opening were elongated slots or ports as this shape seems to reduce the tendency of the ports to become plugged with solids contained in the drilling fluid. With a right-hand threaded connection between the members, relative right-hand rotation between the members will cause them to telescope to the closed position shown in FIGURE l.

In the closed position, two seals are employed to prevent the flow of fluid between the inside and outside of the tool through openings or ports 21. The first is seal ring 22. This is a pressure energized seal located in annular groove 23.

To provide an accessible annular groove for seal ring 22, the lower side of groove 23 is supplied by annular shoulder 27 on the upper end of bushing 12a, which is connected to the upper end of sub 12 by threads 26. The sub is threadedly connected to the housing by threads 24.

The other seal is formed between lower end b of the mandrel and seal ring 30, mounted on .bushing 12a.

When the tool is closed, upwardly facing annular surface 34 on the upper end of the housing engages downwardly facing annular shoulder 35 on the mandrel to provide a torque transmitting connection between the members. Therefore, the length of mandrel 10 below shoulder 35 and the distance below the upper end of housing 11 to seal ring 30 should be closely held to the desired dimensions. The engagement of end 10b with seal 30 not only provides additional security against leakage through the tool, but it also helps improve the lateral stability of the tool by helping to anchor the lower end of the mandrel against lateral movement relative to the housing. The close fit between the outside surface of the lower end of the mandrel and section 11b of the bore also increases the lateral stability of the tool, when it is closed.

Means are provided for limiting the distance mandrel 10 can be withdrawn from housing 11. In the embodiment shown, mandrel 10 is provided with fiange 40 just above threaded section 13. Flange 40 engages downwardly facing shoulder 41 on the housing and limits the distance the mandrel can be unscrewed from the housing.

Shoulder 41 is a part of bushing 44, which is removably attached to the upper end of the housing by threads 45. The upper surface of bushing 44 provides shoulder 34 that engages downwardly facing shoulder 35 on the mandrel and limits the distance mandrel 10 can be screwed into the housing. The engagement of these two shoulders provides lateral stability to the upper end of the tool and as stated above provides a torque transmitting connection between the two telescoping members.

When closing the tool, the drill pipe is rotated to the right (or to the left it left-hand threads are used) and there is no danger that one of the connections in the pipe string will be inadvertently disconnected. When opening the tool, however, it is necessary to rotate the pipe string to the left and this creates the danger that a threaded connection in the tool will be disconnected. To reduce the chances of this occurring, the area or surface 34 is reduced by knurling. Also, preferably the metal on the two shoulders is hardened to reduce the coefiicient of friction between the two shoulders, when they are in engagement. This will reduce the torque necessary to break the connection between mandrel 10 and housing 11 and thereby reduce the danger of a threaded connection in the pipe string being unscrewed inadvertently.

In the embodiment shown, shoulder 34 is knurled with radial grooves 48 that leave lands 49 for engaging shoulder 35. Preferably, a removable bushing, such as bushing 34, is employed so that the bushing can 4be replaced from time to time as required to keep a smooth hard finished surface on shoulder 34. To allow bushing 34 to be easily changed, it is split into two semicircular pieces, which are held in place around mandrel 10 by two bolts 50, only one of which is shown. Once connected together by bolts 50, the bushing can be moved down and attached to the upper end of the housing by threads 45. Set screw 52 insures that the bushing is not unscrewed from the housing, when the tool is opened.

In operation, the tool is installed in the pipe string as shown in FIGURE 1 and the pipe string is run into the hole. When it is desired to circulate through the tool, as for example, to condition the mud in the hole, lefthand torque is applied to the pipe string causing the -threaded connection between threads 13 and 14 to move mandrel 10 and housing 11 axially relative to each other and open ports 21 for circulating purposes. When the circulation has been completed, right-hand rotation will close the tool returning it to position shown in FIGURE 1 and fiuid pumped down the pipe string will travel through the tool and into the lower portion of the pipe string.

The housing section of the tool must not rotate as fast as the mandrel for the tool to open or close. Therefore, there must be Something below the tool, such as a fishing tool in engagement with a fish, that will hold the housing against rotation sufficiently to produce the desired rotation.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus and structure.

It will be understood that certain features and subcombinations are of utility and may be employed with reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. A circulating tool for connecting into a pipe string intermediate its ends comprising first and second telescoping tubular members, mating male and female straight threads on said first and second members, respectively, connecting the members together for axial movement of the first member into the second member when the members are rotated relatively in one sense and for moving the first member axi-ally out of the second member when the members are rotated relatively in the other sense, means limiting the movement of the first member out of the second member to a first position and means limiting the movement of the first member into the second member to a second position, one of said members having at least one lateral opening through which liquid in a well bore can enter and leave the tooi and a pipe string in which it is connected when the members are in t-he first position, means closing the opening when the members are in the second position, said first and second members having oppositcly facing annular shoulders that engage when the members are in their second position to transmit the torque imposed on one mem- 'ber by the pipe string to the other member, when the pipe string is rotated in the one sense, one of said shoulders having a knurled surface providing lands to engage the other shoulder to reduce the area in contact therewith and reduce the torque required to break the threaded connection when the members are in their second position and it is desired to move the members to their first posiltion to permit fluid to circulate through the lateral openlng.

2. A circulating tool for connecting into a pipe string comprising, first and second telescoping tubular members relatively movable axially between a first position and a second position, the first member having one end for connecting to the portion of the pipe string extending above the fill-up tool, the second member having one end for connecting to the portion of the pipe string below the tool and an opening through which the liquid in the Well bore can enter the pipe string when the members are in the first position, mating male and female threads on the first and second members, respectively, connecting the first member to the second member and for moving the members axially from the first position to the second position when the first member is rotated relative to the second member in one sense, and from the second position to the first position when the first member is rotated relative to. the second in the other sense, means for closing the opening when the members are in the second position to stop the flow of liquid into the' pipe string through the opening including a tubular unthreaded lower section of the first member, located below the Imale threads on the member, to move past the opening in the second member when the members move from the first to the second position, a seal ring located below the opening in the second member to engage the lower section and seal off the opening, said second member having a section, below the opening into which the lower end of the male member extends, having a diameter only slightly larger than the lower section, said first and second members further having oppositely facing annular shoulders above their threads that engage when the members are in their second position and cornbine with the lower section of the first member and the close fitting bore of the second member in which it is located to provide lateral stability to the tool when in the second position, one of said shoulders having a knurled surface to reduce the torque required to break the threaded connection between the two members when the members are in the second position and the shoulders are in engagement so the valve can be returned to the first position as required to allow fluid to be circulated between the inside of the pipe string and the annulus outside of the pipe string.

3. A circulating tool for connecting into a pipe string intermediate its ends comprising first and second telescoping tubular members, mating male and female straight threads on said first and second members, respectively, connecting the members together for axial movement of the first member into the second member when the members are rotated relatively in one sense and for moving the first member axially out of the second member when the members are rotated relatively in the other sense, means limiting the movement of the first member out of the second member to a first position and means limiting the movement of the first member into the second member to a second position, said second member having at least one lateral opening through which liquid in a well bore can enter and leave the tool and a pipe string in which it is connected when the members are in the first position, said opening being positioned below the first member when the members are in their first position, said first and second members having downwardly and upwardly facing annular shoulders, respectively, that engage when the members are in their second position to transmit the torque imposed on the first lmember by the pipe string to the second member, when the' pipe string is rotated in the one sense, one of said shoulders having a grooved surface providing lands to engage the other shoulder to reduce the area in contact therewith and reduce the torque required to break the threaded connection when the members are in their second position and it is desired to move the members to their first position to permit fiuid to circulate through the opening in the second member, said first member further having a second downwardly facing annular shoulder on its lower end, said second member having an annular sealing face located below the opening in the second member to engage the second downwardly facing annular shoulder on the lower end of the first member and provide a seal therebetween to prevent the iiow of fluid through the opening.

References Cited UNITED STATES PATENTS 2,905,250 9/1959 Talbott 166--226 2,906,493 9/1959 Whitener 175-317 2,984,451 5/1961 Conrad 166-226 3,100,538 8/1963 Sanders 166237 3,130,788 4/1964 Cochran et al 166-237 I AMES A. LEPPINK, Primary Examiner

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