US2731827A - loomis - Google Patents

Description

Jan. 24, 1956 G. LOOMIS 2,731,827

HYDRAULIC COLLAR TESTER Filed Jan. 11. 1952 s Sheets-Sheet 1 6/9/20 1. Zoom/s INVENTOR.

Jan. 24, 1956 G. L. LOOMIS HYDRAULIC COLLAR TESTER Filed Jan. 11. 1952 3 Sheets-Sheet 2 za 47 4d 6/9/7/7 Z Zoom/J INVENTOR.

KKM

ATTORNEY HYDRAULIC COLLAR TESTER Glenn L. Loomis, McAllen, Tex., assignor, by mesne assignments, of one-half to G. L. Loomis, one-sixteentl1 to John Stahl, one-sixteenth to R. T. Elmore, one-eighth to estate of Florence L. Stahl, deceased, one-twelfth to .l. P. King, Sn, one-twelfth to J. P. King, Jr., and onetwelfth to W. F. King Application January 11, 1952, Serial No. 266,041

11 Claims. (Cl. 73-40.5)

This invention relates to a collar tester apparatus which is used primarily for testing for leaks in a collar joint between two sections of well pipe.

In assembling Well pipe such as casing, tubing, drill pipe, and the like, ordinarily the string of well pipe is formed by a plurality of sections of pipe which are joined together by a collar forming the coupling between adjacent sections. In the majority of instances, the well pipe is prepared at the factory with a collar assembled on the thread of one end thereof. In assembling the well pipe for use in a well the well pipe is lowered with the collar end of the pipe extending just above the floor of the well derrick. While the pipe is being held in this position by means of slips or similar holding means, the next section of pipe to be assembled in the string is added by threading one end thereof into the collar which is exposed above the floor of the well derrick and which is attached to the preceding section of pipe which had been inserted into the well bore. The section of well pipe being added is secured to the section of pipe at the surface of the well by spinning the threaded end of the section being added into the collar of the section of pipe at near the surface of the well. After the section of pipe being added is secured to the collar of the adjacent pipe the string is then lowered so that the collar on the section of pipe being added is now exposed for the addition of another section of pipe. This operation is continued until a desired length of the drill string is obtained.

When the string of well pipe has reached its desired length, which today in many cases exceeds ten thousand feet (10,000), the drilling muds and other fluids are passed into the well. It is not unusual to have the drilling fluids under pressures in the neighborhood of 9,000 pounds per square inch and in the event that a leak or leaks occur in the collar joint between the sections of well pipe, the necessary pressure cannot be maintained. Under the present practice when a leak is present in the collar joint of the drill string it is necessary to pull up the string until the collar joint which is leaking has been located. Such a procedure may involve pulling the entire length up of the drill string. It has also been found that with the present methods and devices for testing the leaks in the collar joint of well pipe, that in numerous instances it may even be necessary to pull the drill string two or three times before the leak in the collar joint is located.- Such a procedure is obviously expensive since it results in a considerable loss of drilling time.

It is therefore an object of this invention to provide an apparatus for detecting leaks in collar joints between sections of well pipe while the well pipe is being assembled at the surface of the well.

Another object of this invention is to provide an apparatus for injecting fluid into a well pipe between the two spaced packers mounted thereon.

Another object of this invention is to provide an apparatus for testing each collar joint at the surface of the well prior to lowering of that collar joint into the well bore.

nited States Patent 2,731,827 Patented Jan. 24, 1956 Another object of this invention is to provide an apparatus in which each successive collar joint of a well pipe may be tested at the surface of the well prior to lowering into the well bore, which apparatus involves a minimum of time for the testing operation.

Another object of this invention is to provide a hydruice lic collar tester apparatus which includes a tester body having packers spaced from each other and mounted exteriorly on the body, and means for moving fluid under pressure to cause the packers to enter into sealing engagement with the well pipe for sealing off a portion of the well pipe adjacent the collar joint to be tested.

Another object of this invention is to provide a hydraulic collar testing apparatus in which a collar tester body has mounted thereon spaced packers which provide a sealing engagement with the well pipe in proximity to the collar joint to be tested, slidable wedges being mounted on the body for movement under hydraulic pressure to force the packers into sealing engagement with the well pipe, and a pop-oil valve for admitting the testing fluid from the collar tester into the sealed off portion of the collar joint between the spaced packers.

Another object of this invention is to provide a collar tester in which a collar finder is associated therewith for locating the collar joints of the well pipe after the well pipe has been inserted into the well bore.

Other and further objects of this invention will become apparent when the following description is considered in connection with the accompanying drawings, wherein:

Fig. 1 is an elevational view illustrating schematically a phase of operation of this invention wherein the apparatus of this invention is employed.

Fig. 2 is a longitudinal sectional view of the collar tester of this invention as shown inserted into a well pipe adjacent a collar joint prior to applying the testing fluids under pressure.

Fig. 3 is a similar view of the collar tester as shown in Fig. 2 and illustrates particularly the stage of operation of the collar tester wherein the slidable wedges have been forced to cause the packers to seal off the well pipe in an area adjacent the collar joints.

Fig. 4 is a view similar to Figs. 2 and 3 but illustrating the phase of the operation of the collar tester subsequent to-that shown in Fig. 3, and particularly illustrating the phase wherein the wedging sleeves have returned to their normal position and the testing fluid has entered into the area between the packers.

Fig. 5 is a horizontal sectional view taken on line 5-5 of Fig. 4 and illustrates particularly the relationship of the wedging sleeves with respect to the packers.

Fig. 6 is a horizontal sectional view taken on line 66 of Fig. 4 and illustrates particularly the opening in the collar tester body for admitting fluid from the collar tester underneath the wedging sleeves.

Fig. 7 is an elevational view, diagrammatically illustrating the testing of collar joints after the collar joints have been lowered into the well bore, whereby a collar finder is used for locating each successive collar joint for testing thereof.

Fig. 8 is a partial longitudinal section illustrating the collar finder device which may be used with the collar tester of this invention.

Fig. 9 is a horizontal sectional view taken on line 9--9 of Fig. 8 and illustrating the finder finger and the release and latching mechanism for the finger.

In the preferred operation of this invention the collar tester apparatus designated generally by the numeral 15 is mounted on the floor 16 of a well derrick 17. The collar tester apparatus 15 includes a flexible support means 18 which may also be the hose or tube for admitting fiuid to the collar tester 20. This support means 18 can be mounted as shown in Fig. 1 by passing it around a hoisting drum 22 and thence upwardly and over a sheave 24 mounted on the derrick 17. Suitable mechanism is provided for operating the hoisting drum 22. For example this may be operated by connection through the drawworks engine, not shown. Pressure fluid for testing may be supplied to the collar tester 20 of the collar tester apparatus by means of a pump designated by the numeral 25. A pressure line 27 from the pump 25 to the support hose 18 supplies the testing fluid from the pump 25 through the hose 18 to the collar tester 20. A pressure guage 28 is preferably used in the line 27 to indicate the pressure of the testing fluid being supplied to the collar tester 20. Also as will be explained more fully hereinafter, the pressure guage 28 serves as an indicating means when the pressure is applied to the collar joint to determine whether or not there is any leakage in the collar joint itself.

In carrying out the preferred operation of this invention a section of well pipe such as shown in dotted lines at 30 is placed in its racked position alongside the derrick 17 just prior to assembly with the drill string already in the well bore. As shown in Fig. 1 it is assumed that the section of well pipe 31 has just been tested at its collar joint 32 and that it is now ready for lowering into the well bore. It will be observed that at the upper end of the section 31 is another collar 33 which had previously been assembled with the section 31 by the manufacturer prior to delivery to the oil well itself. After the collar joint 32 has been tested the derrick hoisting structure 35 is lowered permitting the section 31 of the well pipe to be lowered also to position the section 31 with the collar 33 in proximity to the floor 16 of the well derrick 17. Thus the collar 33 will be lowered to a position substantially the same as the position of the collar joint 32 as shown in Fig. 1. After section 31 has been lowered into the well the collar tester is then easily removed from the section 31 and is inserted onto the section of well pipe 30 at the collar end 36 thereof. The elevators 38 of the derrick hoisting device 35 are then secured to the section 30 and as the derrick hoisting device 35 is raised the section of pipe 30 is also raised permitting the collar tester 20 to slide downwardly through the section 30 so that it is in a position near the end 39 of the section 30 when the section 30 has reached a position which is substantially the same as that shown in Fig. 1 for the section 31. The end 39 of the section 30 has threads thereon which are then threaded into the collar 33 of the section 31. After the threading is accomplished the pressure fluid from the pump is then passed into the collar tester 20 for operating the collar tester and for locating any leaks which might be present in the collar joint formed by the collar 33 on the threaded end 39 of the pipe section 30.

The above operations are then repeated for each successive section of well pipe which is added to the drill string. The actual time which is used in testing is very small and serves to give an indication immediately at the surface of the well as to any leaks which may be present in the collar joints. It will be appreciated that although the hoisting drum 22 and pump 25 with its attached pressure line 27 and pressure guage 28 are shown in Fig. 1 as being on the floor 16 of the derrick 17, they may be located on the ground or any other suitable point for operation. Also it should be understood that although the support means 18 has been indicated as usable for supplying the testing fluid therethrough to the collar tester 20, that in some cases it may be desirable to provide a separate support means 18 and a separate supply of testing fluid to the collar 20 through a tube other than the support means 18. Although it is the preferred operation to simultaneously insert the collar tester 20 in the section of drill pipe or well pipe as it is being raised into position for threading with the preceding collar such as 33 it is also possible in some cases to raise the section 30 and then to lower the collar tester 20 into the section 30 subsequent to the threading of the end 39 into the adjacent collar 33. In fact, the collar tester 20 could be lowered while the threading of the threaded end 39 is being accomplished with the collar 33.

The collar tester 20 which is preferably used in carrying out the operation of this invention is shown particularly in Figs. 2-4 and the operation thereof will be described in connection with these figures. The collar tester 20 is made up of a. tester body 40 which has mounted thereon spaced packers 42 and 43. These packers 42 and 43 can be mounted on the body 40 by various means but it is preferred to use locking nipples 45 and 46 respectively. As can be seen each of the locking nipples 45 and 46 have an inner recess area 47 with a tapered flange forming the outer lip 48. This outer lip or flange 48 contacts the outer edge of the packer 42 or 43 and holds the packer 42 or 43 into intimate contact with the body 40.

Also mounted on the body 40 are the wedging sleeves 50 and 51. These wedging sleeves 50 and 51 are longitudinally slidable with respect to the body 40. Normally the sliding wedge member 50 is urged against a shoulder 52 on the body 40 with the protruding edge 54 of the wedge member 50 contacting the shoulder 52. A resilient means or spring 55 normally contacts the upper edge 56 of the wedging sleeve 50 to force its edge 54 into contact with the shoulder 52. The other end of the resilient means 55 is in contact with a support ring 57 which fits into a recess of the packer 42. Thus because of the position of the resilient means 55, it serves to keep the packer 42 in position against the locking nipple 45 as well as to normally urge the wedging sleeve 50 against the shoulder 52. The wedging sleeve 51 is mounted in a similar manner to the wedging sleeve 50 and it has an edge 60 which contacts a shoulder 61 on the body 40 when the resilient means 62 between the support ring 63 and the edge 64 of the wedging member 51 is acting to urge the wedge member in the upward direction as shown in the drawing.

As shown in Fig. 2 the collar tester 20 has been inserted into a well pipe and has been positioned in proximity to the collar joints 65 and 66 formed by the collar 67 positioned between the adjacent sections of well pipe 68 and 69. In Fig. 2 the testing fluid has not yet been supplied under pressure to the collar tester 20 and as can be seen the tapered edge 70 of the wedging sleeve 50 is in contact with the lower portion 71 of the packer 421, but the spring 55 is still urging the wedging sleeve 50 into abutment with the shoulder 52, so that the packer 42. has not yet been forced into sealing engagement with the section of well pipe 68. Similarly the tapered edge 73 of the wedging sleeve 51 is in contact with the portion 74 of the packer 43 but it has not yet forced the packer 43 into sealing engagement with the section of well pipe 69.

As best seen in Fig. 5 the tapered portion 70 of the wedging sleeve 50 has thereon raised portions 76 which form the contacting means with the Packer 42. Between the raised means 76 is therefore formed the groove 77, the function of which will be detailed hereinafter. Although Fig. 5 only shows the wedging sleeve 50 and its associated elements, it is, of course, understood that the wedging sleeve 51 is provided with raised portions 76 and grooves 77. Formed with the wedging sleeves 50 and 51 are extensions 79 and 80 respectively which contact shoulders 81 and 82 respectively of the body 40.

When the fluid under pressure is admitted to the inside 84 of the body 40 it is prevented from passing downwardly by the closed end section 85 of. the body 40. Provided in the body 40 is a pop-off valve 86 which may be simply of the ball valve type as shown in the drawing, which pop-off valve 86 is set to open at a predetermined pressure. This predetermined pressure setting can be regulated by adjustment of the tension on the spring 87 by moving the nut 88 inwardly or outwardly as desired.

The reason that the pop-off valve 86 is set to open at a predetermined pressure is to permit the operation of the wedging sleeves 50 and 51 prior to the entry of fluid from the inside 84 of the body 40 to the space 90 between the packers 42 and 43. Thus the initial pressure of the testing fluid first causes the fluid to move through an opening 91 for the wedging sleeve 50 and an opening 92 for the wedging sleeve 51. This fluid entering through the openings 91 and 92 is prevented from escaping around the wedging member 50 and 51 by means of O- seal rings 94 and 95 positioned on either side of the openings 91 and 92 between the body 40 and the wedging members 50 and 51. When the fluid pressure for testing has reached a suflicient amount which is still considerably below the pressure set for opening the pop-off valve 86 the wedge sleeves 50 and 51 are moved away from each other in a direction toward their respective packers 42 and 43. As will be appreciated this pressure must be in excess of the force exerted on the wedging sleeves 50 and 51 by their resilient means 55 and 62 respectively, in order to force the packers 42 and 43 into sealing contact with the well pipe. In Fig. 3 it can be seen how the wedging sleeves 50 and 51 have been forced away from each other to cause the packers 42 and 43 to seal off a portion of the well pipe adjacent the collar joints 65 and 66. In the phase of the operation of the collar tester 20 illustrated in Fig. 3 it is assumed that the pop-off valve 86 has not yet opened.

However, in Fig. 4 the pop-off valve has opened and the fluid for testing has entered into the space 90 between the packers 42 and 43. When the testing fluid enters the space 90 it first passes through the grooves 77 of the wedging sleeves 50 and 51 to force the wedging sleeves 50 and 51 to their position in abutting contact with the shoulders 52 and 61 respectively of hte body 40. This return of the wedging sleeves 50 and 51 occurred because the pressure in the inside 84 of the body 40 and in the space 90 has become equalized due to the opening of the pop-off valve 86. Thus the force of the resilient means 55 and 62 then became the only force urging the sliding wedges 50 and 51 so that they are returned to the position prior to the admitting of the testing fluid under pressure. As can be seen in Fig. 4 particularly the effect of the return of the wedging sleeves 50 and 51 to their previous position by the urging of the springs 55 and 62 respectively, permits the testing fluid to force the packers 42 and 43 into a more complete sealing engagement with the well pipe.

When the various parts of the collar tester 20 have assumed the position shown in Fig. 4, the testing fluid then exerts its full pressure on the collar joints 65 and 66. Any leakage may be discovered by the appearance of the testing fluid at the collar joints 65 or 66, but it is preferably determined by the appearance of a loss in pressure indicated on a means such as the pressure guage 28 as shown in Fig. 1.

Actually it is rare that the collar joint 66 will leak because it is that joint which has been formed at the factory by the manufacturer or distributor of the well pipe and generally if a leak occurs it would be in the collar joint 65 which is the one which has been formed in assembling the well pipe at the well. Thus it may be desirable in some cases to test only one of the collar joints 65 or 66 at a time by positioning the collar tester 20 so that only one collar joint is between the packers 42 and 43. Also it will be appreciated that although duplicate packer structure has been shown for each end of the collar tester 20 that one end thereof may be of a different construction than the other.

After the collar joint 65 and/or the collar joint 66 have been under pressure of the testing fluid for a suflicient period to determine whether or not any leaks are present in tht collar joints, then the pressure is reduced by suitable means such as a release valve in proximity to the pump 25 or where ever convenient. When the release valve, not shown, is opened to permit the pressure in the collar tester to be reduced the pressure on the inside 84 of the body 40 then becomes lower than the pressure in the space 90.

In order to permit the testing fluid to escape from the space a flap valve 101 is provided in the body 40. This flap valve 101 may be of any desired construction and may be set to open at any predetermined pressure but as shown in the drawing it includes a plate 102 and a spring 103 resiliently urging the plate 102 against a nut 104 having an opening 105 therein. There is also a hole 106 in the body 40 to admit the pressure fluid from the space 90 into the inside 84 of the body 40. When the pressure is thus reduced in the space 90 the packers 42 and 43 are released from sealing engagement with the well pipe and thereafter the collar tester 20 can be moved to a different position. Also the Well pipe can then be moved longitudinally with respect to the collar tester 20.

It will be observed that above the locking nipple 45 is a section of tubing 108 which may serve as a lock nut for the locking nipple 45 as well as serving for additional support for the entire collar tester 20. In some instances it may be desirable to provide a by-pass tube 109 which preferably would extend through an opening 110 in the tube 108 and from there pass downwardly to the central portion of the body 40 to enter a passage 112 in the plug portion 85 of the body 40.

This by-pass tube 109 may be secured in the body 40 by a weld 113 or similar affixing means. The purpose of the by-pass tube is to enable other fluids to be passed through the collar tester during the testing operation. This may be desirable in some cases where it is desired to provide a continuous flow of drilling fluid circulating throughout the casing while inserting the drill string into the well bore.

Although the preferred operation of this invention in-- cludes the provision of a flexible support 18 for the collar tester 20 it may sometimes be desirable to provide a rigid type of support such as 115 shown in Fig. 7. This is particularly desirable where it is contemplated that the collar joint along the drill string which has already been inserted within a well bore is to be tested. For example, it may happen that a leak is not discovered at the surface of the well while inserting the well pipe into the well bore. In such cases if a leak should develop in the well pipe it is necessary to lower the collar tester into the well pipe and to test each successive collar joint by using the same collar tester 20 as previously described. However, a modification in the collar tester 20 is necessary to enable the collars to be located within the well bore since they are not visible as they would be when performing the operation as described in connection with Fig. 1.

To accomplish the finding or location of the collars in the string of well pipe within the well bore a means for finding the collars has been provided in the modification particularly shown in Figs. 7-9. This means for finding the collar may take various forms but one form which is suitable is particularly shown in Figs. 8 and 9 wherein a finger 116 is mounted in the body 40 on a pivot 117. A spring or resilient means 118 is mounted between the finger 116 and a notch 120 in the member 40. The spring 118 normally urges the finger 116 outwardly. When it is desired to locate the collar the finger 116 is extended outwardly of the body 40 to a position shown in Fig. 8 whereby the finger 116 can contact an edge of a section of well pipe such as 120 shown in Fig. 8. When the finger 116 contacts the edge 120 the longitudinal movement of the collar tester 20 in the well pipe is stopped and the hydraulic fluid is passed into the collar tester 20 to perform the testing operation as explained in connection with Figs. 2-4. After the testing operation has been completed and it is desired to retract the finger 116 this can be done by rotation of the inner member 121 of the body 40 with respect to the outer member 122 of the body 40. Suitable J-slots 123 are provided in the outer member 122 to permit the movement of pins 124 in the J-slots 123 to cause the finger 116 to retract upon a clockwise motion of the inner member 121 as seen in Fig. 9. A beveled surface 125 is provided on the body 40, or more particularly on the outer member 122. Thus as the members 121 and 122 are rotated with respect to each other the finger 116 moves along the beveled surface 125 in the body 40 to its retracted position which movement is in opposition to the urging of the resilient means 118. In the retracted position the finger 116 does not extend outwardly beyond the edge of the body 40 so that the collar tester 20 can be freely moved longitudinally with respect to the Well pipe. The crook 127 in each of the J-slots 123 enables the device 20 to be moved longitudinally without danger of releasing the finger 116 until desired. However, when it is desired to release the finger 116 it is only necessary to turn the member 121 counterclockwise with respect to the member 122 as shown in Fig. 9 so that the spring 118 can again urge the finger 116 outwardly of the outer edge of the body 40 so that it is in a position to contact the next succeeding edge 120 of a section of well pipe.

By utilizing the finger 116 in combination with the collar tester 20 it is possible to run the collar tester 20 up and down the well string and test each successive collar joint to locate the leakage without the necessity of pulling the entire drill string from the well bore. Although it will be appreciated that such an operation is not nearly as satisfactory as testing the collar joint at the surface of the well prior to positioning therein, the operation is still far superior to the present day practice of removing the entire drill string until the leaky collar is located.

It will also be appreciated, that although this operation has been described for treating one or both of the collar joints at a single collar, that by suitably extending the spacing between the packers on the tool, the joints at more than one collar may be tested to enhance the speed of testing a long drill string.

It is to be understood that the pipe may be assembled at the factory with a collar by threading, welding, shrink fitting, or any other known aflixing means. Although the unattached end of the collar will normally be threaded for convenience in assembling and disassembling at the well, it is conceivable that this joint may also be welded or affixed by other means, and it is therefore to be understood that this invention is not limited to testing or treatment of threaded joints.

It is believed readily apparent that an apparatus has been devised whereby leaks in collar joints between adjacent sections of well pipe may be located with a minimum of time and expense.

Broadly this invention contemplates an apparatus for locating leaks in collar joints between adjacent sections of well pipe joined by a collar.

What is claimed is:

l. A collar testing apparatus for testing for leaks in collar joints formed by a collar coupling together adjacent lengths of a well pipe, comprising a tester body having an inner passage therein for receiving a testing fluid under pressure, packers mounted exteriorly of said body to seal ofl a collar joint in a well pipe, wedging sleeves slidably mounted on said body, passages in said body to permit testing fluid under pressure to urge said wedging sleeves into contact with said packers for causing said packers to initially seal off said collar joint, and a valve in said body set to open at a predetermined pressure of testing fluid higher than the pressure of testing fluid necessary to actuate said wedging sleeves to cause said packers to initially seal off said collar joint, said valve when operable admitting the testing fluid into the well pipe between said 8 packers to release said wedging sleeves from contact with said packers and maintain said packers in sealing engagement with said well pipe so that any leaks in the collar joint will be detected by a loss of pressure or the appearance of testing fluid at the collar joint.

2. A collar testing apparatus for testing for leaks in collar joints formed by a collar coupling together adjacent lengths of a well pipe, comprising a tester body having an inner passage therein for receiving a testing fluid under pressure, packers mounted exteriorly of said body to seal off a collar joint in a well pipe, wedging sleeves slidably mounted on said body, passages in said body to permit testing fluid to urge said wedging sleeves into contact with said packers for causing said packers to seal off said collar joint, a. valve in said body set to open at a predetermined pressure to admit the testing fluid into the well pipe between said packers so that any leaks in the collar joint will be detected by a loss of pressure or the appearance of testing fluid at the collar joint, and grooves on the exterior of said wedging sleeves at their point of contact with said packers to permit said wedging sleeves to be released from contact with said packers so that said testing fluid provides the pressure for holding said packers in sealing engagement with the well pipe.

3. A collar testing apparatus for testing for leaks in collar joints formed by a collar coupling together adjacent lengths of a well pipe, comprising a tester body having an inner passage therein for receiving a testing fluid under pressure, packers mounted exteriorly of said body to seal off a collar joint in a Well pipe, wedging sleeves slidably mounted on said body, passages in said body to permit testing fluid to urge said wedging sleeves into contact with said packers for causing said packers to seal oil said collar joint, a valve in said body set to open at a predetermined pressure to admit the testing fluid into the well pipe between said packers so that any leaks in the collar joint will be detected by a loss of pressure or the appearance of testing fluid at the collar joint, grooves on the exterior of said wedging sleeves at their point of contact with said packers to permit said wedging sleeves to be released from contact with said packers so that said testing fluid provides the pressure for holding said packers in sealing engagement with the well pipe, and a second valve for admitting said testing fluid from the well pipe to the inside of said collar tester for the diminishing of the pressure at the collar joint.

4. A collar tester apparatus for testing for leaks in a collar joint of well pipe comprising means for supporting a collar tester to enable insertion of said collar tester into a section of well pipe as said section is threaded to a collar of a previously run section of well pipe, means for admitting testing fluid under pressure into said collar tester, packers on said collar tester to seal off a portion of said well pipe adjacent said collar joint, mechanical means on said collar tester operable by the testing fluid under pressure within said collar tester for contacting and expanding said packers into initial sealing engagement with said well pipe, and means in said collar tester operable at a predetermined pressure of said testing fluid higher than the pressure necessary to actuate said mechanical means to initially seal off said packers, said last-mentioned means permitting the testing fluid therein to enter into the well pipe between said packers to equalize the pressure acting on said mechanical means to release the same from contact with said packers and to exert a force to maintain said packers in sealing engagement with said well pipe, said last mentioned means also admitting the testing fluid into the well pipe between said packers to test for leaks in the collar joint.

5. A collar testing apparatus for testing for leaks in collar joints formed by a collar coupling together adjacent lengths of a well pipe, comprising a tester body having an inner passage therein for receiving a testing fluid under pressure, packers mounted exteriorly of said body to seal otf a collar joint in a well pipe, wedging sleeves slidably mounted on said body, passages in said body to permit testing fluid to urge said wedging sleeves into contact with said packers and causing said packers to initially seal off said collar joint, a pressure responsive valve mounted in said body and set to open at a predetermined pressure to admit the testing fluid into the well pipe between said packers, and means on said wedging sleeves responsive to the opening of said valve for permitting pressure of the testing fluid on the wedging sleeves to equalize and release the same from contact with said packers, said last mentioned means also permitting the testing fluid to maintain said packers in sealing engagement with the well pipe.

6. A collar tester apparatus to test for leaks in collar joints formed by a collar coupling together adjacent lengths of well pipe comprising a tester body having an inner passage therein for receiving a testing fluid under pressure, packers mounted exteriorly of said body to seal ofi a collar joint in a well pipe, wedging sleeves slidably mounted on said body, passages in said body for permitting testing fluid under pressure to urge said wedging sleeves into contact with said packers for causing said packers to initially seal otf the collar joint, and means in said body operable in response to a predetermined pressure of the testing fluid higher than the pressure of testing fluid necessary to actuate said wedging sleeves to initially seal ofl said collar joint, said lastmentioned means when operable permitting testing fluid to enter the space between said packers to release said wedging sleeves from contact with said packers and maintain said packers in sealing engagement.

7. A collar tester apparatus to test for leaks in collar joints formed by a collar coupling together adjacent lengths of well pipe comprising a tester body having an inner passage therein for receiving a testing fluid under pressure, packers mounted exteriorly of said body to seal off a collar joint in a well pipe, wedging sleeves slidably mounted on said body, resilient means normally urging said wedging sleeves away from said packers, passages in said body cooperating with said wedging sleeves to permit testing fluid under pressure to urge said wedging sleeves in opposition to said resilient means for causing said sleeves to force said packers into initial sealing engagement with the well pipe, and means in said body operable in response to a predetermined pressure of the testing fluid higher than the pressure of testing fluid necessary to actuate said wedging sleeves to initially seal olf said collar joint, said last-mentioned means when operable permitting testing fluid to enter the space between said packers to release said wedging sleeves from contact with said packers and maintain said packers in sealing engagement.

8. A testing device for use in testing a section of well pipe comprising a body member of smaller diameter than the inside diameter of the well pipe to be tested, said body member having a bore therein closed at one end thereof, means for supplying a testing fluid under pressure to the bore of said body member, spaced packer elements mounted exteriorly of said body member and also having a smaller diameter than the diameter of well pipe to be tested, means for causing said packer elements to seal oil a section of well pipe and including at least one passage positioned in said body adjacent each of said packers, said passages adapted to permit testing fluid under pressure in the bore of said body to pass therethrough and cause said packers to seal 01f the section of well pipe to be tested, a pressure responsive valve positioned in said body member between said packer elements and being operable by testing fluid in the bore of said body member at a predetermined pressure higher than the pressure necessary for sealing said packer elements, said pressure responsive valve when actuated permitting the testing fluid to enter into the section of well pipe between said packer elements to test the section of well pipe therebetween for leaks, and means to relieve pressure of testing fluid between said packer elements when the pressure of testing fluid in said bore is relieved.

9. A testing device of the character described in claim 8 wherein said last-mentioned means includes a second valve positioned in said body member between said spaced packer elements, said second valve adapted to allow testing fluid to flow from the section of well pipe being tested into the bore of said body member when the pressure on the testing fluid is released.

10. A testing device for use in testing a section of well pipe comprising a body member of a smaller diameter than the inside diameter of the well pipe to be tested, said body member having a bore therein closed at one end thereof, means for supplying a test fluid under pressure to the bore of said body member, spaced packer elements mounted exteriorly of said body member and having a smaller diameter than the diameter of the well pipe to be tested, means for causing said packer elements to seal off a section of well pipe and including passages positioned in said body member adjacent each of said packer elements, said passages adapted to permit testing fluid under pressure in the bore of said body to pass therethrough and cause said packers to initially seal off the section of well pipe to be tested, a pressure responsive valve positioned in said body member between said spaced packer elements and being operable by the testing fluid in the bore of said body member at a predetermined pressure higher than the pressure necessary to actuate the means for initially sealing said packer elements, said pressure responsive valve when actuated permitting the testing fluid in the bore of said body to enter into the section of well pipe initially sealed off by said packer elements and to equalize the pressure on and cause said initial sealing means to be released while maintaining the seal of said packer elements with said well pipe.

11. A testing device of the character described in claim 10 wherein said body member includes a second valve positioned therein between said spaced packer elements, said second valve adapted to allow testing fluid to flow from the section of well pipe being tested into the bore of said body member when the pressure on the testing fluid is released.

References Cited in the file of this patent UNITED STATES PATENTS 1,802,525 Newlin Apr. 28, 1931 2,241,526 :7 Rosenkranz May 13, 1941 2,330,659 Anderson Sept. 28, 1943 2,587,192 Meyer Feb. 26, 1952 2,589,430 Fletcher Mar. 18, 1952 2,610,691 Berry Sept. 16, 1952 2,605,843 Baker Aug. 5, 1952 2,652,717,/ Bush et a1. --..-i. Sept. 22, 1953

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