US2912273A

US2912273A - Pipe engaging tool

Info

Publication number: US2912273A
Application number: US457877A
Authority: US
Inventors: Chadderdon Jack; Jr Albert L Burns
Original assignee: Houston Oil Field Material Co Inc
Current assignee: Houston Oil Field Material Co Inc
Priority date: 1954-09-23
Filing date: 1954-09-23
Publication date: 1959-11-10
Anticipated expiration: 1976-11-10

Description

Nov. 10, 1959 J. CHADDERDON l:1'1"\l- 2,912,273

PIPE ENGAGING TOOL 5 Sheets-Sheet 1 Filed Sept. 23, 1954 Jack Chaa a eraon A/be/Z L. Bur/134A:

INVENTORS 7- w j 'ATTOR/VEYJ Nov. 10, 1959 J. CHADDERDON ETAL PIPE ENGAGING TOOL Filed Sept. 25, 1954 5 Sheets-Sheet 2 Nov. 10, 1959 Filed Sept. 23, 1954 J. CHADDERDON HA1.

km: ENGAGING TOOL /00 v v s //I///U I y m 5 Sheets-Sheet 3 (Jack Ch aaaerc/on A/berf L Bur/7s, Ur. INVENTORS A TTOR/VE v.5

Nov. 10, 1959 CHADDERDQN EI'AL 2,912,273

PIPE ENGAGING 'rooL Filed Sept. 25, 1954 5 Sheets-Sheet 4 Jack Chara dew 0 00 A/ber/ L. a

Arrog/v e rs United States Patent PIPE ENGAGING TOOL Jack Chadderdon, Long Beach, Calif., and Albert L. Burns, Jr., Houston, Tex., assignors to Houston Oil Field Material Company, Inc., Houston, Tex, a corporation of Delaware Application September 23, 1954, Serial No. 457,877

8 Claims. (Cl. 294-86) This invention relates to a tool and, more particularly, relates to a tool which may be lowered into a well bore to engage and retrieve pipe in the bore.

This application is a continuation-in-part of the application of Jack Chadderdon and Albert L. Burns, Jr., Serial No. 265,164, filed January 5, 1952 for Pipe Engaging Tool now abandoned.

In the drilling of oil wells and the like, it frequently happens that a length of pipe becomes stuck in the well bore for many reasons, such as by twisting olf the drill string, untimely uncoupling of members of the drill string and the like. It is desirable to recover as much of the pipe left in the well bore as possible in order to salvage the pipe and to prevent abandoning the well, among other costly operations.

There are several methods and means for recovering stuck pipe in a well bore. One of these methods comprises placing the stuck pipe under torque tending to unthread lengths of such pipe and impacting a joint, such as with an explosive, to initiate or effect unthreading of the desired joint.

The present practice in recovering stuck pipe by this method calls for two separate operations. First, a rotary shoe of sufficient inside diameter to go over the stuck pipe and its tool joints is lowered into the hole on the lower end of a large diameter pipe, commonly referred to as wash pipe, sufiicient in inside diameter to telescope over the stuck pipe. This wash pipe is attached at its upper end to a string of drill pipe of sufiicient length to reach the depth of the stuck pipe. As the rotary shoe progresses downwardly over the stuck pipe, successive lengths of drill pipe may be added. Ordinarily, the pipe is manipulated with respect to the stuck pipe so that the stuck pipe projects inwardly and upwardly into the wash pipe. During the lowering over the stuck pipe, the string of drill pipe, the wash pipe, and the rotary shoe are rotated so that the shoe tends to dig out material that is sticking to the sides of the stuck pipe.

Customarily during this operation mud fluid is pumped down through the string of drill pipe, the wash pipe, and out into the formation adjacent the rotary shoe so that the cuttings are carried away from the vicinity of the operation. This procedure is continued until it is determined that the pipe has been freed from the well bore, .or until the rotary shoe becomes dulled, or until the operator determines that he has washed out over all the stuck pipe possible.

The entire string of pipe is then withdrawn from the well and a second operation is effected to remove all or a portion of the stuck pipe. This second operation may be done in a number of ways, such as threading or securing pipe from the surface in or to the stuck pipe, and lowering an explosive inside the pipe proximate the joint sought to be uncoupled. The stuck pipe is placed under torque tending to disconnect a desired threaded coupling and the explosive is detonated to effect or initiate unthreading of this threaded coupling.

2,912,273 Patented Nov. 10, 1959 If the second operation is successful, the drill pipe" along with the disconnected portion of the stuck pipe, and any tools utilized, are withdrawn from the well bore. If an additional length of pipe remains stuck in the well bore, the rotary shoe is replaced on the end of the wash string and lowered into the well bore to cut the formation away from the stuck pipe as indicated in connection with the first operation. After this is completed, the second operation is again effected.

In deep wells it is apparent that considerable man hours are lost in recovering pipe in this manner which requires at least two separate round trips into the well bore. Also, when the wash pipe is removed, there is a possibility that the formation will again stick to the stuck pipe and prevent a successful disconnection of the stuck pipe during the second operation.

A primary object, therefore, of thepresent invention is the provision of a tool which releases the stuck pipe and provides means for placing the stuck pipe under torque or torque and tension tending to disconnect a threaded connection thereof in order that impacting of the threaded connection will initiate or effect a disconnection of the threaded joint.

Another object of the present invention is the provision of a combination tool through which drill fluid may be circulated to be discharged adjacent a rotary shoe on the lower end thereof.

Another object of the present invention is the provision of a combination washover and backofi? connector which canbe engaged and released at will from the stuck pipe.

A further object of the present invention is the provision of a combination washover and backoff connector which is exceedingly simple, inexpensive to manufacture and repair, which has a minimum of parts, and which is rugged and durable in use.

A further object of the present invention is the pro- .vision of a tool to which can be secured means to dig or cut away material sticking to sides of the stuck pipe, and which may be actuated merely by raising or lowering the manipulating string of pipe to which the tool is secured to place the stuck pipe under torque or permit the means to dig away material to rotate without placing the pipe under torque.

After a pipe engaging tool has been connected tothe stuck pipe or fish it is desirable to impact it while applying torque or torque and tension on the pipe to initiate unthreading of the stuck pipe to recover sections thereof. Ordinarily, impacting means are used for this purpose, such as an explosive, and in order to introduce the explosive into the pipe it is necessary to raise and remove the kelly at the surface. In other pipe engaging tools it is necessary to disconnect the pipe engaging tool from the stuck pipe and reconnect it to the stuck pipe in performing this operation. It is hazardous and time-consuming to disconnect and reconnect the pipe engaging tool to the stuck pipe.

Accordingly, it is a further object of the present invention to provide a pipe engaging tool which includes a safety or releasing joint so that the tool or elements thereof do not have to be disconnected from and reconnected to the stuck pipe when raising the kelly for introducing a pipe impacting means into the operating string of pipe.

Other and further objects will be apparent from-the following description of tools constructed in accordance with the invention, and by reference to the accompanying drawings, where like character references designate like parts throughout the several views, and where Figure 1 is a diagrammatic elevation, partly in section, of a combination tool constructed in accordance with the invention, and shown in position as it is lowered into the well bore and washing or telescoping over stuck pipe,

Figure 2 is similar to Figure l and illustrates the construction of Figure l in a position after it has engaged the stuck pipe,

Figure 3 is similar to Figures 1 and 2, and illustrates the construction of these figures in a position for placing the stuck pipe under torque to effect a disconnection.

Figures 4A, 4B; 4C and 4D are enlarged fragmentary vertical sectional views, with parts broken away, illustrating the constructionof Figure 1,

Figure 5 is a diagrammatic elevation, partly in section, of another example of a combination tool constructed in accordance with the invention, and shown in position as it is lowered into the well bore, and before it engages the stuck pipe,

Figure 6 is similar to Figure 5 and illustrates the construction of Figure 5 in a position to continue rotation of the wash pipe without placing the stuck pipe under torque,

Figure 7 is a cross-sectional view illustrating an alternate example of securing the stuck pipe engaging element with the mandrel of the tool,

Figure 8 is a vertical sectional view taken along the line 8-8 of Figure 7,

Figures 9 and 9A are enlarged fragmentary sectional elevations, with parts broken away, illustrating the construction shown in Figures 5 and 6, and

Figure 10 is a cross-sectional view taken along the line 1 P10 of Figure 9.

Referring now to the drawings, and particularly to Figures l3, the reference numeral 19 designates the tool or combination washover and backoff connector which as a whole comprises the generally tubular body 12 to which washover pipe M- is connected and the tubular mandrel 16 which is slidably disposed in body 12. The washoverpipe l i'may be connected in any preferred manner to the lower end of tubular body 12 so as to telescope over the stuck pipe or fish 18 upon rotation of the body 12. The tool It? is connected to a string of pipe 29 which extends to the surface of the earth, not shown, by which the tool 10 is manipulated.

Slidably disposed in the body 12 and extending downwardly therefrom toward the upper portion of washover pipe 14- is the tubular mandrel 16 which has the pipe engaging element 22 secured to its lower end and the head member 24 integral with or secured in any preferred manner to its upper end, which head member 24 is slidable in the tubular body 12.

As best seen in Figures 4A to 4C the body 12 preferably includes an upper tubular sleeve 26 at the upper end, an intermediate sleeve 23, a lower sleeve 39, and a washover pipe connector 32, each threadedly secured to the other in axial alignment to form the body 12 of the tool It). The upper sleeve 26 is secured to the intermediate sleeve 28 by the complementary threads and the intermediate sleeve 28 is in turn secured to the lower sleeve 34) by the complementary threads 36 although these may be connected in any desired manner. Suitable packing, such as the O-

rings

38, 4e, 42 and 44, may be provided to prevent leakage at these connections and any preferred sealing means may be utilized.

The lower sleeve 3t) is in turn secured in axial alignment or end to end relation with the washover pipe connector 32 by a thread type safety joint 46 which may be packed off by O-ring 3. inasmuch as the safety joint 46 as such forms no part of the present invention and any type of safety joint may be used, as well as omitted if desired, no detailed description thereof is necessary.

The inner diameter of the intermediate sleeve 23 is reduced with respect to that of the upper sleeve 26 in which the head member 24 moves. This reduction in di ameter forms a restriction or internal shoulder in the body 12 through which the mandrel 16 passes. The lower portion of the intermediate sleeve 28 is counterbored to provide the downwardly tapering shoulder 50 which, when the tool is in the position shown in Figures 1, 2, 4A 311643, abuts against the complementary tapering shoul- Cir der 5?. or" stop member 54 which stop member is slidablein the intermediate sleeve 2?; below the shoulder 50. Positioned around mandrel 16 and below the stop member 54 is a resilient means, such as the coil spring 56, the upper end of which engages stop member 54 and the lower end or" which rests on stop member 5% which is seated on and is thereby secured by packing gland 6b to the lower portion of the intermediate sleeve 28. To prevent the entry of drilling fluid into the space where the spring 56 functions, packing, such as O-ring 62 and its retainer ring 64, may be used.

Within the intermediate sleeve 28 the exterior diameter of the mandrel 16 is reduced to provide a recess complementary to the counterbored portion of the intermediate sleeve Z% for receiving the spring 56. This reduced diameter provides a downwardly tapering shoulder 76 against which the complementary tapering shoulder of stop member 54 abuts when shoulder '7!) is at or below shoulder Si) in the intermediate sleeve 28. Thus, when the mandrel in is moved in relation to spring 56 so that shoulder 7% on the mandrel strikes shoulder 72 on stop member 54, the stop member 54 will be forced towardthe lower stop member 58 thus compressing the resilient means 56 between these two stop members.

As best seen in Figure 4B the upper end of the intermediate sleeve 28 which forms a restriction or internal shoulder in body 12 and the lower end of head member 2 have the coacting clutch elements as and 68, respectively, to impart rotation to mandrel in upon rotation of body 12 when the clutch elements are engaged, as indicated in Figure 3. The coil spring 5-6 normally retains the clutch elements out of engagement and thus the mandrel 16 and the head member 24 are slidable and rotatable in the body 12; and the upper portion of the washover pipe 14 when these and the subsequently-described clutch elements are not engaged.

Referring again to Figure 4A, the upper end of body 12 is closed by the threaded tool joint or coupling 74!- which is internally threaded at its upper end to be secured to the manipulating string of pipe 2b. The coupling or tool joint 74 has a downwardly facing internal shoulder '76 which has the downwardly projecting cam elements 78 which are engaged by cam elements 80 disposed at the upper end of head member 24 on mandrel 16. These cam elements 78 and 8t) may be made integral with the tool joint 74- and the head member 24 respectively but it is preferred that they be detachable in order that they may be replaced as they wear. The bolts 81 as illus trated in Figure 4A are quite satisfactory for holding the cam elements 73 and 80 to the tool joint 74 and head member 24, respectively, although the bolts 81 are i1lustrated only in connection with the tool joint 7 4.

The cam elements or

surfaces

78 and 80 may be in the form of tapering truncated teeth, as indicated in Figure 4A, so that when the tool 10 has engaged the upper portion of the stuck pipe 18 and the mandrel 16 is in the uppermost position as illustrated by Figure 2, rotation of the tool will percussively jar the mandrel 16 and the stuck pipe 18 by virtue of the cam surfaces or elements '7? and 8t slipping with respect to one another. Inasmuch as the mandrel 1116 becomes fixed upon engagement with stuck pipe 13, it will not rotate, thereby causing the slippage of cam surfaces 78 and 89. While the elements 73 and 36 are referred to as cam elements they may also be clutch elements to impart rotation to the mandrel 16, if desired, or to impart rotation until they slip over each other.

As illustrated in Figure 4A, a piston sleeve 122 may be provided about the head member 24, if desired, as a bearing surface and wiper for ease of operation.

in order to circulate drilling mud from the surface down through the tool, on the outside of the stuck pipe, and between the washover pipe 14 and the stuck pipe 18 to remove cuttings, to lubricate the various pipes, and to cool the rotary shoe and the like, the manipulating string of pipe 20 extending to the surface has a fluid passageway 82. A fluid passageway 84 is provided in tool joint 74 and wash tube 85 communicates between passageway 84 through head member 24 and axial bore 86 of mandrel 16. This wash tube 85 is threadedly or otherwise secured to tool joint 74 by the complementary threads 88 and is slidable with relation to mandrel 16. The axial bore 86 continues on down through the mandrel 16 and through pipe engaging element 22. A series of ports 90 are drilled through pipe engaging element 22 in order that some fluid may circulate between the stuck pipe 18 and wash pipe 14.

The pipe engaging element 22 includes a safety joint such as the bayonet or J-slot safety joint 92 and the actual pipe contacting portion which may be of any conventional type, such as a spear or other pipe engaging means, or may take the form of a downwardly extending tapered tap 94 as best seen in Figures 1 and 4D. The tapered tap 94 is for the purpose of being engaged with the upstanding box member 96 of the upstanding stuck pipe 18. Also included in stuck pipe engaging element 22 is clutch element 98 on the upper end thereof.

Referring to Figures 4C and 4D, for ease of construction, the pipe engaging element 22 comprises a clutch sleeve 100 secured in axial alignment to a fluid port sleeve 102 by a sub 104. A pin type safety joint 92 is threaded to the lower end of the fluid port sleeve 102, the safety joint 92 including the telescoped pin 106 and box 108 when the joint is made up. A clutch sleeve 100 is secured to the mandrel 16 and this may be done by the complementary threads 110 as shown in Figure 4C. The sub 104 which secures the clutch sleeve 100 to the fluid port sleeve 102 is a conventional sub connecting these two sleeves and may preferably include the set screws 112. Any conventional means such as the tapered complementary threads 114 on the lower end of fluid port sleeve 102 and the pin 106 forming the upper end of the safety joint 92 may be used to connect these two members together.

The safety joint 92 includes the pin 109 which has a reduced diameter portion 106 extending therebelow. The pin 109 and its reduced diameter portion 106 fit into the upper end of the box 108 of the safety joint 92. The safety joint 92 is a quick and ready releasable and reengageable connection and, for this purpose includes the J-slots 111 which are provided by the reduced diameter or cut out portion 106 of the pin 109 into which the lugs 113 provided on the interior portion of the box 108 are movable. Preferably, a packing ring 115 is provided to pack the safety joint, such as at the free extremity of the reduced diameter portion 106 of the pin 109 below the J-slots 111. Inasmuch as any preferred type of safety or quick releasing and quick making up joint may be used, no more description thereof is deemed necessary. The purpose of this safety joint or quick release and re-engageable joint will subsequently be explained in more detail.

Referring again to Figure 4C it can be seen that the lower sleeve 30 of the body 12 is provided with a clutch element 120 which coacts with the clutch element 98 on the upper end of the pipe engaging element 22 for a purpose and in a manner which will later be explained in more detail.

In operation, in the event pipe becomes stuck in a well bore, the tool may be lowered into the well bore on the end of the manipulating string of pipe and manipulated from the surface. The washover pipe 14, depending upon the conditions in the well bore and the amount of stuck pipe therein, may extend some three hundred to five hundred feet or more below the body 12 of the tool 10. While not shown, a conventional rotary shoe is ordinarily secured to the lower end of the washover pipe 14. As the washover pipe is worked and lowered down into the well bore, it is worked over the box member 96 at the upper end of the st uck pipe 18 pipe, and to cool the rotary shoe.

and is rotated by rotating body 12 to cut away formation from the sides of the stuck pipe 18. As the washover pipe 14 is rotated, drilling fluid is circulated down through the manipulating string of pipe 20 and the tool 10 to wash away cuttings and aid in removing them, to lubricate the During this milling operation the parts of the tool will assume the position shown in Figure 1, the mandrel 16 being held by its weight against the coil spring 56.

After the desired amount of washover pipe 14, which can be ascertained in advance, is washed over the stuck pipe 18, the pipe engaging element 22 will engage the upstanding box 96 at the upper end of stuck pipe 18. Continued lowering and rotation of body 12 causes the elements to assume the position illustrated in Figure 2, so that the

cam elements

78 and 80 come into engagement and impart rotation to mandrel 16, making up the tapered tap 94 in the upstanding box 96. After the tapered tap 94 has been engaged into the box 96, the mandrel 16 isheld stationary by the stuck pipe 18, and the

coacting cam elements

78 and 80 will ride over one another imparting a percussive jarring action to the mandrel 16 and in turn to stuck pipe 18, if such is desired.

The operating string 20 may then be raised until the

clutch elements

66 and 68 engage, as illustrated in Figure 3, at which time the tool may be rotated to complete the threading of tap 94 in box 96 if necessary. After the tap 94 is engaged in box 96, rotation of the body 12 in a direction tending to unthread the sections of pipe making up the stuck pipe 18 applies a torque to the stuck pipe also in a direction tending to unthread joints of stuck pipe.

If desired, tension may be applied through the tool 10 to the stuck pipe 18 by applying tension to the manipulating or operating string of pipe 20 which relieves the pipe connections of the weight of superposed sections of pipe.

If it is desired to impact a particular joint of stuck pipe 18 internally, it will probably be necessary to raise the kelly on the drill rig and remove the kelly so that the impacting means may be passed down the manipulating string 20. In order that the kelly and its depending manipulating string of pipe 20 can be raised the tool 10 1 must be raised and heretofore it was necessary to disengage the pipe engaging element from the stuck pipe. The safety joint 92 permits the tool 10 to be raised without disconnecting the engaging element from the stuck pipe so that the prima cord can be lowered into the stuck pipe and subsequent operations performed. A predetermined upward pull on the manipulating string of pipe 20 puts a corresponding upward pull on the pin 109 and shears the shear pin 118 causing the pin 109 to move upwardly as far as is permitted by the short arms of the J-slots 111 and the lugs 113. By setting down on the drill string 20 the

coacting cam elements

78 and 80 will engage and may be used to rotate the pin 109 so that on a subsequent upward pull of the drill string the lugs 113 will be positioned to slide in the run out legs of the J-slots 111 thereby disconnecting the safety joint 92 but leaving the pipe engaging element 94 connected to the fish or stuck pipe 18.

At this time the means to impact the particular joint of stuck pipe 18 internally, such as prima cord, is lowered inside the manipulating string of pipe 20 through

the'fluid passages

82, 84, and 86, and inside the stuck pipe 18 to a point proximate a threaded connection sought to be disconnected. During this time the kelly is reconnected and the safety joint is reconnected by moving the run out leg down between the lugs 113 and rotating the pin 107. Due to the fact the lugs 113 will move down into the short legs of the J-slot 107 on upward pull of the manipulating string of pipe, torque may be applied through the

clutch elements

66 and 68 to the mandrel 16 and to the stuck pipe 18. The threaded connection is then impacted while applying torque or torque and tension tending to disconnect it. The impact may be applied by any preferred means, such as an explosive, as broadly disclosed in Kinley, Patent No. 2,305,261, issued December 15, 1942. The use of prima cord as explosive is satisfactory. if the connection is not completely disconnected, further rotation of the tool will complete the disconnection and the whole may be lifted from the well bore.

Thus, afer the stuck pipe has been engaged the stuck pipe 18 thereafter may be placed under torque or torque and tension tending to disconnect threaded connections, at which time an explosive is detonated internally and proximate a particular joint sought to be disconnected to initiate or effect disconnection of the joint. Inasmuch as the washover pipe 14 has freed the stuck pipe 18 from the formation, the stuck pipe, tool and wash pipe may be removed from the well bore in a single trip. It is noted that the entire removal operation is efiected in a single round trip, during which time the wash pipe may be constantly rotated and drilling fluid circulated between the wash pipe and stuck pipe and up the wash pipe. Also, it is unnecessary to disconnect the pipe engaging element from the stuck pipe and again attempt to con 1163;; it, which is a time consuming and sometimes difiicult tas The lower clutch consisting of

clutch elements

98 and 120 is engaged in the event the body 12 should become separated above the safety joint 46 and also permits that section of body 12 above this line of separation to be freed from all that part of tool 10 below this line of separation including the mandrel 16 in the event the tool becomes stuck. If this should occur a conventional tapered tap or some similar tool may be placed on the lower end of a manipulating string of pipe and lowered into the hole so as to engage the remainder of the body 12. After such engagement has been made engagement of the

clutch elements

98 and 120 permits rotation to be imparted to the mandrel 16 and thus to the stuck pipe 18 in order to manipulate it to free it.

Referring to the example of the invention illustrated in Figures 5, 6, 7, 8, 9, 9A and 10 and with special reference to the last three of these figures, the means to prevent relative rotation between the mandrel 16a and the body 12 is provided by having a splined or hex portion 124 on the mandrel 16a, and a complementary splined or hex portion 126 disposed in the sub 3011 which sub provides a restriction or internal shoulder in body 12 similar to that provided by spring sleeve 28. The splined or hex portion 124 constitutes a relatively short portion of the total length of the mandrel 16a when compared with the distance the head member 24 can move relative to the body 12. Thus, when the mandrel 16a is in a 'lowermost position, as illustrated in Figures and 9, rotation of the body 12 will impart rotation to mandrel 16a. The

clutch elements

66 and 68 as shown in Figure 4B, which prevent relative rotation between body 12 and mandrel 16 and coil spring 56, are thus omitted. It will be understood that any preferred means may be used to prevent rotation of the mandrel and the body, preferably while placing the stuck pipe under tension. In this example, the invention includes the omission of the

cam elements

78 and 80 illustrated in Figure 4A. Also, the wash tube 85 is omitted and the head member 24 is packed off by packing ring 134} secured to the upper end of head member 24 by means of a dove tail arrangement generally indicated by the reference numeral 132. In this example, a further modification is illustrated in that the tool joint or coupling 74a is made integral with the upper end of body 12 and the body 12 no longer is constructed of an upper sleeve 26, an intermediate sleeve 28, lower sleeve 3% and washover pipe connector 32 but instead has merely the tubular body 12 and the internally enlarged body portion 30a; although, of course, the body may be made of one or more parts connected together.

This example of the invention illustrates that the fluid ports may be drilled into the lower end of mandrel 16 instead of through pipe engaging unit 22'. Also clutch elements 98 and may be omitted.

In Figures 7 and 8 there is illustrated a modified type of safety joint 92a. Here, the lower end of mandrel 16a is splined or fluted as at 134 and the upstanding end of the pipe engaging element 22 is similarly splined or fluted as at 135 in order that relative rotation between the mandrel 16a and the pipe engaging element 22' is prevented. The shear pins 136 may be provided through the connection between the lower end of mandrel 16a and the pipe engaging element 22. Thus, in applying torque tending to unthread the connections in the stuck pipe, there is no likelihood that the pipe engaging element 22 will become disconnected from the mandrel 16a and, in the event the stuck pipe cannot be removed from the well bore and the tool it freed from the stuck pipe 18, a predetermined upward stress will shear the pins 136 whereby all but the pipe engaging element 22 of the tool 1% may be withdrawn from the well.

In this embodiment a safety joint 92b, such as the safety joint 92 of Figures 1, 2, 3 and 4D, may be placed between the manipulating string 20 and the head of tubular body 12 or may be omitted, if desired.

The other elements of this example are the same as the example first described, and with reference to Figures 5 and 6, the mandrel 16a assumes a lowermost position as the tool is lowered into the well bore and rotated about the stuck pipe 13 to cut away formation which causes the pipe to be stuck in the well bore. As the tool continues to be lowered, rotation of the mandrel 16a, by means of the

splined portions

124 and 126 on the mandrel and the internally enlarged body portion 39a, mat-2e up the connection 94 between tapered tap and the upper end of the box 96. After the joint is made up, continued lowering will cause the splined portion 124 to more out of the splined portion 126 of the internally enlarged body portion 30a, as best seen in Figure 6, and the washover pipe 14 may be continued to be rotated about the stuck pipe 1% without applying any torque to the latter.

As indicated in connection with the operation of the first example, an explosive such as prima cord may be lowered from the surface through the manipulating string of pipe 29, the tool, and into the passage in the stuck pipe 18 until it is positioned proximate a joint sought to be disconnected. The manipulating string of pipe 20 may then be raised and rotated in a direction tending to unthread the lengths of pipe making up the stuck pipe 18 and, upon raising the tool 10, the hex portion 124 on the mandrel 16a moves into the hex portion 126 in the sub 3911 which places the stuck pipe 18 under a torque, or if desired under torque and tension, tending to unthread the particular joint. At this time, the joint may be impacted, such as by detonating the prima cord, which either initiates or effects a disconnection of the desired joint. Further rotation completely disconnects the joint sought to be disconnected and the tool may be removed from the well, as well as the stuck pipe, all in one trip, as described heretofore. Also, in this example, the manipulating string of pipe 20 may be raised to remove the kelly and permit the introduction of the detonating means by means of the J-type safety joint 92!) between the manipulating string and body 12.

It will be understood that while the various elements of the tool are indicated as being threaded together, they may be integral or welded, and ordinarily the washover pipe is secured to the tool as it is lowered into the well bore. The washover pipe may or may not be at the well, and thus the tool includes the omission of the washover pipe, which may be secured to the tool when used.

From the examples of the invention given for the purpose of disclosure, it is apparent that numerous changes in e details and arrangements of parts may be made.

Broadly, the invention comprises a combination tool for washing or telescoping over stuck pipe, including means to engage the stuck pipe and to apply torque or torque and tension thereto or permit wash pipe to be rotated without applying torque to the stuck pipe. Preferably, means should be provided to permit circulation of the drilling fluid during the operation and through which impacting means may be lowered to initiate disconnection of the stuck pipe. Also, a safety joint preferably is incorporated in the tool so that the kelly can be raised to introduce impacting means into the operating string of pipe without disconnecting the tool from the fish. Thus, the invention is to be limited only by the spirit of the invention and the scope of the appended claims.

What is claimed is:

l. A tool for lowering on a pipe string into a well bore and engaging stuck pipe in the well bore to effect release thereof comprising, an elongate tubular body attachable to the string of pipe, the lower end of the of the engageable means and rotation of the body rotation is imparted to the mandrel, and ports in the, mandrel in fluid communication with the fluid passage in the mandrel and disposed below the restriction in all positions of the mandrel whereby fluid circulated through the pipe string passes through the mandrel, out the ports and between the washover pipe and the stuck pipe.

2. The tool of claim 1 including resilient means disposed between the upper portion of the internal restriction and engaging anupper portion of the mandrel, said resilient means acting upwardly to yieldingly hold the mandrel up relative to the body.

3. A tool for lowering on a string of pipe into a well bore and telescoping over and engaging stuck pipe therein to cflect release thereof comprising, an elongate tubular body attachable to the lower end of the string of pipe, 21 washover pipe disposed at the lower end of the body for telescoping over the stuck pipe, an inwardly extending restriction in the body provided with an axially aligned passage therethrough, a mandrel slidably and rotatably carried by the body and extending through the passage in the restriction, a pipe engaging element carried by the lower end of the mandrel for connecting the mandrel to the stuck pipe, engageable means on the restriction and on the mandrel so that upon engagement of the means and rotation of the body rotation is imparted to the mandrel, communicating fluid passageways in the mandrel and in the pipe engaging element in fluid communication with the passage in the pipe string, and ports in the mandrel in fluid communication with the passageway in the mandrel and disposed below the restriction in all positions of the mandrel whereby fluid circulated in the string of pipe passes into the mandrel, out the ports and out the pipe engaging element.

4. The tool of claim 3 where the engageable means comprises complementary splined portions on the upper portion of the mandrel and in the restriction.

5. The tool of claim 3 including a releasable and reengageable connection carried by the mandrel whereby the tool may be released from the stuck pipe without disengaging the pipe engaging element.

' 6. A tool for use with a pipe string for lowering into a well bore and telescoping over an engaging stuck pipe therein to effect release thereof comprising, an elongate tubular body attachable to the pipe string, a washover pipe extending from the lower end of the body for telescoping over the stuck pipe, an inwardly extending shoulder provided with an axially aligned opening disposed in the body, a mandrel slidably and rotatably carried by the body and extending through the opening in the internal shoulder, a pipe engaging element carried by the lower end of the mandrel, engageable means in the body adjacent the restriction and on the mandrel so that upon engagement of the engageable means and rotation of the body rotation is imparted to the mandrel, a fluid passageway in the mandrel in fluid communication with the fluid passage in the pipe string, and ports in the mandrel in "fluid communication with the fluid passageway in the mandrel and disposed below the shoulder in all positions of the mandrel whereby fluid circulated through the pipe string passes through the mandrel and out the ports and between the washover pipe and the stuck pipe.

7. A tool for use with a pipe string for lowering into a well bore and telescoping over and engaging stuck pipe therein to effect release thereof comprising, an elongate tubular body attachable to the pipe string, washover pipe disposed at the lower end of the body for telescoping over such stuck pipe, an inwardly extending shoulder in the body provided with a central passage, a mandrel slidably and rotatably carried by the body and extending through the passage in the internal shoulder, a pipe engaging element carried by the lower end of the mandrel,

engageable means in the body adjacent the shoulder and 011 the mandrel so that upon engagement of the engageable means and rotation of the body rotation is imparted to the mandrel, a fluid passageway in the mandrel, a

fluid passageway between the mandrel and body whereby fluid circulated through the pipe string flows through the tool and between the body and the mandrel, and a releasable and re-engageable connection carried by the mandrel for release and rte-engagement of the mandrel with the pipe engaging element after engagement thereof with the stuck fish. I

8. A tool for lowering into a well bore ona string of pipe and for telescoping over an engaging stuck pipe therein to effect release thereof comprising, an elongate tubular body attachable to the string of pipe, a washover pipe extending from the lower end of the body for telescoping over the stuck pipe, an inwardly extending shoulder in the body provided with a central passage,

a mandrel slidably and rotatably carried by the body and extending through the passage in the internal shoulder, a pipe engaging element carried by the lower end of the mandrel, engageable means on the internal shoulder and on. the lower portion of the mandrel so that upon engagement of the engageable means and rotation of the body rotation is imparted to the mandrel, engageable cam elements on the body and on the upper portion of the mandrel, said cam elements including engageable faces inclined away from the direction of rotation of the body so that upon engagement of the inclined faces and rotation of the body rotation is imparted to the mandrel until the mandrel becomes fixed by engagement of the pipe engaging element in the stuck pipe and on continued rotation of the body in the same direction, the inclined faces ride over one another, permitting relative rotation between the body and the mandrel which has become