US3280917A

US3280917A - Well tester

Info

Publication number: US3280917A
Application number: US333222A
Authority: US
Inventors: Iii James W Kisling
Original assignee: Schlumberger Well Surveying Corp
Current assignee: Schlumberger Well Surveying Corp
Priority date: 1963-12-24
Filing date: 1963-12-24
Publication date: 1966-10-25
Anticipated expiration: 1983-10-25

Description

4 Sheets-Sheet l J. W. KISLING lll WELL TESTER Oct. 25, 1966 Filed Dec. 24. 1963 .mrzrr JOl/VT INVENTOR.

dame: 14 ///.r ///79' 17 Oct. 25, 1966 Filed Dec. 24, 1963 J- W. KlSLlNG lll WELL TESTER 4 Sheets-Sheet 2 INVENTOR.

Oct. 25, 1966 J. w. KISLING m 3,

WELL TESTER Filed Dec. 24, 1963 4 Sheets-Sheet 3 James W. /f/J///7y U INVENTOR.

4 Sheets-Sheet 4 J. W. KISLING Ill WELL TESTER INVENTOR.

,4 SEA/7 2 7 a 9 w B a y H a P x A lg K M A X w m/q dqfl h a y w w w I 6 V II] Oct. 25, 1966 Filed Dec. 24 1965 United States Patent Ofiice 3,280,917 Patented Oct. 25, 1966 3,280,917 WELL TESTER James W. Kisling III, Houston, Tex., assignor to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Filed Dec. 24, 1963, Ser. No. 333,222 8 Claims. (Cl. 166-150) This invention relates to apparatus for use in a well bore and more particularly to apparatus for making multiple flow tests in a well bore.

Drill stem tests are normally performed by lowering a strong of tools including a testing tool and packer to a desired depth of testing. The packer is set usually by applying force through the drill strong, the packer iso lating or packing-oif the formation to be tested. Subsequently a test valve in the testing tool is open and closed by rotations of the drill string while the force on the drill string is maintained on the packer. The number of times that such a valve may be opened and closed is limited to one or two separate openings and closings and requires a given number of rotations for each operation. Rotation or torquing of the drill string for opening and closing operations is disadvantageous in that all the threaded connections in a tubing string may not be completely made up, therefore the given number of rotations may be taken up by the string of tubing with out effecting an operation of the valve in the tool. Also the tubing string may become lodged in the hole intermediate the length of the tubing so that the string of tubing twists above the lodged point without transferring the rotating motion to the tool. Subsequently, the tubing string may twist itself free and then make several un controlled revolutions on the lower part of the tubing string which may adversely afiect the valve operation. These features of torquing movement involving the uncertainty of the number of turns of the tubing string give the operator little evidence of the position of the tool element in the operations being performed by the tool.

It is therefore an object of the present invention to provide a new and improved apparatus for making multiple flow tests in a well bore which apparatus utilizes a vertical movement of the tubing string to perform the various operations in the tool.

Another object of the present invention is to provide an apparatus for making multiple tests of a formation utilizing longitudinal movement of the testing tool to perform the test operations.

Yet another object of the present invention is to provide a new and improved bypass valve to be used with the formation testing tool.

A further object of the present invention is to provide a new and improved apparatus for packing-01f the well bore in such a way as to facilitate longitudinal movement of the testing tool and yet maintain the packer in a set condition.

A still further object of the present invention is to provide a new and improved series of full-opening tools which utilize longitudinal movement to make multiple tests of a formation.

With these and other objects in view, the present invention contemplates an apparatus for making multiple tests on a formation. More particularly, the apparatus includes a series of tools each including telescopically mounted members arranged to selectively move between longitudinally spaced operating positions. The series of tools includes tester means, bypass means, jar means, safety joint means and packer means.

The tester means includes means permitting opening and closing of a flow valve by longitudinal stroking movement of the drill string to place the telescoping members in spaced longitudinal positions and in each of such positions, force can positively be applied to the packer.

The bypass means includes means for quick closing of the valve and delayed opening so that the tester valve can be operated.

The jar, and safety joint means are provided to uncouple the tester and tubing string from the packer in the event of sticking and are compatible to the operation of the tester valve.

The packer means can be locked expanded during testing to enable upward and downward movement of the testing tool without unseating the packer.

The novel features of the present invention are set forth in particularity in the appended claims. The present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a view in elevation of a series of well tools suspended from a string of pipe and arranged for going in a well;

FIG. 2 is an elevational view of an alternative apparatus connected in the series of tools for isolating the formation to be tested;

FIGS. 3A and 3B are detailed vertical sections of the well testing tool in accordance with the present invention;

FIG. 4 is a developed view of an index slot system used in the tester;

FIG. 5 is a detailed vertical section of a bypass valve;

FIGS. 6 and 7 are detailed vertical sections of a releasably locked packer device;

FIG. 8 is an enlarged detailed cross-sectional view taken along line 8-8 of FIG. 7 of a valve utilized in the packer device;

Referring first to FIG. 1, a Well tool 20 is arranged to be connected to the lower end of a string of pipe or tubing 21 and includes a tester section 22, a by-p'ass' section 23, a jar section 24, a safety joint section 25, a packer section 26, and a perforated anchor section 27. The anchor carries conventional pressure recorders 28 and has perforations 29 in the wall of the anchor section to permit fluid to flow into a bore in the packer mandrel and up through the string of tools. Two pressure recorders are provided, one recorder measuring pressure externally of the anchor and the other measuring pressure internally of the anchor.

In the operation of the well tool as shown in FIG. 1,

permits a more rapid descent of the tool int-o the well bore. When the anchor 27 is seated on the bottom :of the borehole, further downward pressure on the tool will cause an elastorner packer element 125 to be expanded in the well bore to isolate the formation to be tested from the rest of the well bore. Formation fluids enter the tool through the perforation 29 in the anchor section and flow upwardly through the various tools to the tester section 22. Valves in the tester section are opened and closed to flow and shut in the formation fluids. The recorders housed in the anchor section are used to measure the pressure of the fluids during the flowing and shut-in periods.

FIG. 2 illustrates an alternative method of locating the well tool tester wit-h respect to the formation to be tested wherein a conventional wall anchor 31 is used toposition the tool 20 in the well bore at the desired depth and a pair of spaced packers 3'2 and 33 are utilized to straddle the formation to be tested. The wall anchor 31 is also used to set the packers.

Referring now to FIGS. 3A and 3B, details of the tester section of the tool will be described. The tester section 22 generally includes a telescopically-arranged mandrel 36 and housing 41 respectively arranged for coupling between a pipe string 21 and the other sections of the tool. The tester mandrel 36 has a central bore 37 formed therein and intermediate of the length of the bore is a closure plug or barrier 38 (FIG. 3B) shear pinned at 39 to the mandrel and sealingly received therein. The housing 41 is divided into an upper housing section 42 and lower housing section 43 which are rotatably connected to one another by interlocking and cooperating

flanges

46, 47 on the

sections

42, 43.

Flanges

46, 47 provide a swivel type connection so that the upper housing 42 can be rotated with respect to the lower housing 43.

The upper housing 42 has an index pin 48 projecting into an indexing slot system 49 formed in the mandrel 36. The indexing slot system is shown in a developed view in FIG. 4 and will hereinafter be more fully explained. The upper housing 42 also has an internal recess 51 with an inwardly-projecting spline or lug 52 disposed intermediate of the lengt of th'e recess. Housing spline 52 forms an abutment for an upper spline 54 projecting outwardly from the mandrel 36 into the housing recess 51. Splines 52, 54 are engaged and disengaged by operation of the slot system. Mandrel 36 further has a lower outwardlyextending spline 56 which is slidably received Within a longitudinally-extending spline groove 57 in the interior of the lower housing.

The slot system as shown in FIG. 4 includes an upper pocket B, an intermediate pocket H and a pair of lower pockets G and A. The upper pocket and intermediate pocket are longitudinally aligned relative to one another while lower pockets G and A are equidistantly spaced to either side of the intermediate pocket H. Inclined and longitudinal slots are provided to connect the upper and lower pockets as well as the lower and intermediate pockets to one another and guide the index pin 48 in a predetermined manner. For example, if the index pin is initially in the lowermost pocket A, the following sequence of movements will produce the following described travel of the index pin:

(a) Upon downward movement of the mandrel, the index pin is guided from the lower pocket A to the upper pocket E,

(b) Upon upward movement of the mandrel, the index pin is guided from the upper pocket E to the lower pocket (c) Upon downward movement, the index pin is guided from the lower pocket G to the intermediate pocket H,

((1) Upon longitudinal movement of the mandrel upwardly relative to the upper housing, the index pin is guided from the intermediate pocket H to the lower pocket A.

From this description, it will be readily grasped that as the mandrel is moved longitudinally up and down, the

4 index pin will follow a predetermined cyclic path. Hence, with the lower housing section 43, held stationary, the spline 56 and spline groove 57 maintain the mandrel 36 against rotation and the upper housing section 42 will be rotated by virtue of the index pin 48 following the slot system 49.

The slot system fiunctions to place the upper housing spline 52 and mandrel spline 54 in engagement when the index pin is in the intermediate pocket H so that downward iorces can be transmitted from the mandrel 36 directly to the housing 41 and specifically, lower housing 43 via the splines 52, 54, and the upper housing 42. In this manner, the mandrel 36 can be pushed down on the housing 41 to apply weight to the string of tools therebelow. When the index pin is moved to the lower pocket A and then toward the upper pocket, the splines are meshed when the index pin moves between points B and C on the slot system (by virtue of relative rotational displacement) and a collar 58 on the upper end of the mandrel 36 is brought into abutting relationship withthe upper end 59 of the housing 41 so that the mandrel can again be pushed down on the housing.

The lower housing 43, below the spline grooves 57, has a bore portion 61 with an enlarged internal diameter forming a cylinder 62 which receives a hydraulic delay piston 63 in the form of a sleeve between the cylinder wall and the mandrel. This annulus formed between the bore 61 and mandrel 36 is filled with a hydraulic fluid and sealed by floating annular piston and

seal members

66 and 67, positioned respectively at each end of the bore (FIGS. 3A, 3B). The delay piston 63 abuts on one end against an upper, annular valve seat 68 formed by a flange 69 on the mandrel 36. A delay valve spring 71 is disposed between a lower flange 72 on the mandrel 36 and the lower end of the piston 63. Spring 71 normally urges the piston 63 toward the seat 68 on the valve seat flange 69. The outer diameter of the piston 63 is less than the diameter of the bore 61 to form a restricted orifice 73. Hence, as the mandrel 36 is moved downwardly relative to the housing 41, the piston 63 seats on the valve seat flange 69 and the flow of hydraulic fluid int-o the cylinder 62 is metered between the piston 63 and cylinder Wall 61 through the restricted orifice 73. This has the effect of delaying movement of the mandrel downwardly relative to the housing.

A relief chamber '76 with a larger diameter is formed in the lower end of the cylinder wall 61 so that when the piston 63 is moved into the relief chamber 76, a larger fluid flow passage is provided between the piston and the housing. This permits the mandrel to jump or make a sudden movement downwardly at a terminal portion of its downward travel, causing the collar 58 to Strike and engage the upper end 59 of the housing 41 sending a shock wave to the surface through the string of pipe to give a surface indication that the index pin 48 is within the mandrel pocket E.

On the other hand, when the mandrel is moved upwardly relative to the housing, the fluid above the piston 63 will move the piston downwardly relative to the mandrel to compress the spring 71. The inner wall of the piston is provided with longitudinal grooves 77 which permit the fluid to by-pass between the piston 63 and the mandrel 36 so that the mandrel can be picked up relative to the housing relatively fast as compared to the downward movement of the mandrel.

Below the hydraulic delay system, the housing has a bore portion (FIG. 3B) which slidably and sealingly receives the lower end of the mandrel. The housing bore portion is recessed to provide an annular trap or sample chamber 78 between the housing 41 and mandrel 36. A flow port 79 is provided in the bore portion above the recess 78 and extends between the wall of the bore portion and an annular cavity 81 in communication with the recess. Below the recess in the bore portion, the bore portion is similarly provided with a flow port 82 extending between the wall of the bore and an annular cavity 83 in the end of the housing.

The mandrel has spaced sealing elements 86 disposed to either side of -a recessed portion 87, the sealing elements being arranged to seal the mandrel 36 relative to the bore above each of the

housing flow ports

79, 82. The mandrel 36 also has a flow port 88 disposed above the upper seal and above the plu 38. When the mandrel is moved downwardly relative to the housing, the mandrel recess 87 between the mandrel sealing elements places the lower flow port 82 in communication with the sample chamber 78 and the upper flow port 79 in communication with the mandrel port 88.

The mandrel 36 is threaded on its lower end at 89 so that a portion 36a of the mandrel below the threaded joint may be removed. Removal of the lower portion 36a also removes the lower sealing element 86 and thereby renders the mandrel 36 incapable of sealing ofi the trap chamber 78. In this condition, when the mandrel 36 is moved up and down relative to the housing the lower flow port 82 is placed directly into and out of communication with the mandrel port 88 through upper flow port 79 in the housing.

In FIG. 5 the by-pass section 23 of the tool is illustrated. The by-pass section 23 includes a tubular mandrel telescopically received within a tubular housing 92, the mandrel and housing respectively being adapt-ed for coupling in the string of tools 20. A spline 93 on the upper part of the mandrel cooperates with a spline groove 94 in the :by-pass housing permitting relative reciprocation but preventing relative rotation therebetween. The spline 93 engages a flange 96 on the housing in an expanded position of the by-pass section While a shoulder 97 on the mandrel engages the housing flange 96 in a contracted position. Intermediate of the housing is a bore portion 98 forming a cylinder which slidably receives a tubular sleeve piston 99 slidably mounted for limited longitudinal movement between a bypass flange 101 and seat flange 102 on the mandrel. The sleeve piston 99 has a slightly smaller diameter than the diameter of the cylinder bore thereby forming a restricted orifice 103. The ends of the annular chamber 98 formed between the mandrel and housing are closed by a pair of floating,

compensation pistons

106, 107 which enclose a fluid within the chamber. When the mandrel '91 is moved downwardly relative to the housing 92, the fluid in the chamber moves the sleeve piston 99 upwardly and longitudinally-extending grooves 108 in the interior of the sleeve as well as passageways 109 in the by-pass flange permit fluid to easily by-pass the sleeve piston 99 and permit the by-pass section to be rapidly moved to a contracted position. However, when the mandrel 91 is moved upwardly relative to the housing 92 to an expanded position, the fluid above the piston 99 causes the piston to seat on the seat 102 and fluid is metered through the restricted orifice 103 between the sleeve piston and cylinder bore. Hence, the mandrel movement upwardly relative to the housing is delayed and retarded.

The lower end of the housing has a by-pass port 111 while the lower end of the mandrel has a sealing element 112 so that, in the contracted position of the mandrel and housing, the by-pass port is closed by the sealing element 112 and the floating piston seal 107.

The packer assembly is shown in FIGS. 68. The packer assembly 26 includes telescopically-mounted mandrel 116 and housing 117 which are respectively arranged for coupling to the tool sections above and below the assembly. At the lower end of the mandrel is a flange 118 and an annular back-up plate 119. An annular elastomer packing element 125 is received on the mandrel between the lower back-up plate and an upper back-up plate 121. The housing has a flange 122 abuting the upper back-up plate. It will be appreciated that if the housing 117 is moved downwardly relative to. the

mandrel 116, the packing element 125 can be expanded to engage the wall of the well bore as shown in FIG. 7.

In the upper part of the mandrel and housing is a system for releasably retaining the packer element in an expanded condition. For this system the mandrel has upper 126 and lower 127 flange portions slidably and sealingly received in the housing and forming a recess or

chamber

128, 129 therebetween, the chamber being filled with a hydraulic fluid. The housing has an inwardly-extending piston 131 which is slidably received in the chamber and forms upper 128 and lower 129 recess portions. Upper 132 and lower 133 passageways extend longitudinally through the piston to a valve 134. It will be appreciated that if the valve is opened in the position shown in FIG. 6, connecting the upper 132 and lower 136 passageways to one another, fluid will pass from the lower recess portion 129 to the upper recess portion 128 when the housing 117 is moved downwardly relative to the mandrel 116 to the position shown in FIG. 7. With the packer element 26 expanded, closing of the valve 134 and taking the upper 132 and lower 133 passageways out of communication will trap fluid in the upper recess portion 128 and prevent the housing from moving upwardly relative to the mandrel.

The valve system includes a port 135 in the mandrel 116'opening to a recessed portion 136 of the piston be tween spaced seals 137 and a control port 138 in the piston opening to the valve 134. As shown in FIG. 8, the valve includes a sleeve 141 retained in a bore 142 of the housing, the sleeve 141 having a first annular groove 143 and ports in communication with a first passage 144 and a second annular groove and ports 156 in communication with a second passageway 157. It will be appreciated that FIG. 8 illustrates both upper 132 and lower 133 passageways for convenience of understanding although one of the passageways would not be seen in the section view. The illustration also demonstrates that the upper and lower passageways are offset relative to one another at their access points to the valve.

A bore 158 in the sleeve 141 opens at one end to the exterior of the tool and at the other end to the control port 138. Received in the sleeve bore is a spool type piston 159 arranged for movement between a position placing the upper and

lower passageways

132, 133 in communication and a position where the upper and lower passageways are isolated from one another. A spring 161 is provided to normally urge the piston to a position placing the passageways in fluid communication with one another. The piston in the position illustrated has a first portion 162 closing off the sleeve ports leading to passageways, the first portion, however, having a slightly smaller diameter than the bore of the sleeve permitting some fluid leakage to occur. When fluid pressure exterior of the housing is greater than fluid pressure at the control port 138 (which is connected by the piston recess 136 and mandrel port 135 to the interior of the mandrel) and the force of the spring 161, the piston 159 will assume the illustrated position where the first portion 162 of the piston isolates the first 144 and second 157 passageways from one another. When the fluid pressure exterior of the housing is less than the fluid pressure at the control port 138 and the force of the spring 161, the piston is shifted so that a recessed portion 163 of the piston places

passageways

144, 157 in communication with one another.

The fluid leakage mentioned above is for the purpose of obtaining release of the valve eventually should a mal function occur. Thus the packer is never irretrievably set in the well bore.

The difierential pressures to control the spool valve are obtained in a manner which will hereinafter be more fully explained.

The operation of the apparatus of FIGS. 3-10 may best be understood by use of the following table in connection with the description following.

Condition 1 Condition 2 Condition 3 Condition 4 Condition 5 Going in Setting packer Open Tester Close Tester Open by-pass Tester section 22 Expanded Expanded, slowly- Contracted Expanded to inter- Expanded.

moving to conmediate position. tracted. Index position A A toward 0 E to G to H G or A. Shoulder 58 and Not engaged Not engaged Not engaged.

housing end 59. Splines 52 and 54 Moving to meshing Engaged Do.

relationship. Test port 88 Closed Closed. Sample'chamber 78 Do.

Bypass section 23 Expanded. Port 111 Open.

Packer assembly 26.. Expanded.

Packer element 12 Contracted Expanded Contracted. Valve 134.-. Open Closed Clo d Open.

Condition 1 the packer 1s closed trapping fluid in the upper recess In going-in the well bore, the various elements and tool parts are in the conditions above noted. In the packer assembly, the valve 134 (FIG. 8) is open because the pressure of the fluids within the packer mandrel 116 are the same as the pressure of the fluids on the exterior of the tool so that the spring 161 places the spool piston 159 in a position where the upper and

lower passageways

132, 133 are in fluid communication.

The by-pass 23 is held in an expanded position by the weight of the tool attached to the by-pass housing 92 so that the by-pass port 111 is open and fluid can pass through the packer mandrel 116 and return to the well bore via the by-pass port 111.

In the testing section, the sample chamber 78 and test ports are closed while the index pin is disposed in pocket A.

Condition 2 Upon reaching the level of the test, the packer element 125 is expanded. This occurs because the packer mandrel 116 is fixed relative to the well bore. Fixing the mandrel may be by contact with the bottom by the perforated anchor 27 or by Setting a hook wall anchor as shown in FIG. 2. It should be noted that for use of a hook wall packer, the conventional J slot control can be operated because all of the sections are spline connected to permit rotation. While splines are not shown in the packer assembly 26, it will be appreciated that this connection can easily be furnished between the mandrel 116 and housing 117.

As stated heretofore, the packer mandrel is fixed and a downward motion on the string of pipe is transmitted through the tool sections to move the upper packer housing 117 relative to the packer mandrel 116 and expand the packer element 125. As the packer element expands, the =by-pass section 23 contracts to close the by-pass port 111 bringing the by-pass mandrel shoulder 97 into abutment with the by-pass housing. In the tester section the fluid in the delay system is trapped below the piston 63 and very slowly meters through the restricted orifice 73. At this time, the index pin is moving from pocket A toward pocket E and rotating the upper housing 42 to place the splines '52, 54 in meshing relationship to one another. Well before the tester section becomes contracted the packer is fully expanded and the =by-pass is closed.

Condition 3 After the packer is fully expanded, the delay piston 63 in the tester section reaches the recessed portion '76 and very quickly permits the tester mandrel and housing to contract and very quickly opens the mandrel test port 88 and sampling chamber 78 to the bore of the well tool which extends down to the perforated anchor 27 below the expanded packer. This quick motion is apparent at the earths surface and gives an indication to the operation that the tool is properly operating. Because the interior of the string of pipe and the formation pressures are considerably less than the hydrostatic pressure of the well fluid above the expanded packer, the valve 134 in 128 of the packer assembly. At this time, the tester mandrel shoulder 58 engages the upper housing 42, the bypass shoulder 97 en-gages the by-pass housing 92 and downward pressure on the string of pipe can be continuously maintained on the packer element to ensure that it will remain expanded. During this condition the index pin has traveled from position C into the slot E.

Condition 4 After fluid has flowed for a sufiicient period of time, say fifteen minutes, the tester is closed for say five minutes to obtain a shut-in pressure. To close the tester the string of pipe is picked up a suflicient distance to index the pin from the upper pocket E to the lower pocket G and then set down to index the pin to the intermediate pocket H.

In picking up the string of pipe, the delay valve in the tester opens to permit quick by-pass of fluid and movement of the tester section to the expanded condition. At the same time, the delay valve in the by-pass retards movement of the by-pass to an expanded position and the closed valve 134 in the packer assembly prevents release of the expanded packer element 125. The splines 52, 54 in the tester section are meshed once again and the mandrel spline 54 disposed above the housing spline 52. Thus, when the string of pipe is set down and the index pin goes to the intermediate pocket the splines are brought into abutment and direct force on the string of pipe is once again directly transmitted to the packer assembly to positively hold the packer element expanded to close oif the formation while the pressure of the formation fluids is measured.

When the tester is closed a fluid sample is trapped in the sample chamber 78. If it is desired to retrieve the well tool, picking up of the drill pipe moves the index pin from pocket H to pocket A.

On the other hand, it is desirable to repeat the above sequence of operations a number of times which permits the formation fluids to eventually flush out the filtrate and a true recovery from the formations to be obtained.

To determine when the fluid recovery is formation fluids, a gas flowmeter 10 (FIG. 1) is connected to the string of pipe at the surface. As fluids enter the string of pipe the displacement of air in the pipe is indicated by the flowmeter. At a point where the formation fluid flow stabilizes the gas flow becomes constant indicating completion of the test.

Condition 5 In order to retrieve the tool string 20 and the fluid sample trapped in the chamber '78, the packer element must be contracted to release the tools from the well bore. This step may be accomplished :by picking up on the tool string to close the tester valve and trap a fluid sample at formation pressures. Thereafter, the bypass mandrel 91 is lifted up relative to the by-pass housing 92. A continued lifting force on the mandrel 91 will permit sufficient fluids to leak by the by-pass piston 99 through the restricted orifice 103 to allow the mandrel and seal 112 to uncover the by-pass port 111. The opening of port 111 subjects the inner bore of the tool sections to the hydrostatic pressure of the well fluids thereby increasing the inner bore pressure and consequently communicating the increased pressure with the control port 135 of the packer. This pressure in turn acts with spring 161 to move the piston 159 forward and open the valve 1314- to connect the upper and

lower passageways

132 and 133. The valve opening permits expanding movement of the packer mandrel and housing to release the packer element 125 from compression and engagement with the well bore.

Tool retrieval Further upward movement of the tubing string will withdraw the tool string from the well bore.

If the tool string should become lodged in the well bore below the safety joint, the tubing string may be rotated above the joint to release the upper part of the string for retrieval to the surface. In order to affect the loosening of the threads in the safety joint, it may be necessary to lower an explosive element or string shot into the full open bore of the tool string to the level of the safety joint whereupon the shot is detonated to loosen the joint for subsequent unthreading by rotation of the tubing string. The knock-out plug 38 which serves the purpose of blocking the tester section mandrel bore 37 during flow testing of the well may be removed by dropping an object in the bore of the tubing string which object serves to shear the pin 39 to knock out the plug 38. This opens the bore for lowering of the string shot to the safety joint section 25.

After retrieving the tool to the surface, it is necessary to analyze the sample trapped in the chamber 78 at the conditions under which it was trapped. To effect this purpose, a plug 85 is threadably receive-d in the wall of the lower tester housing 43 (FIG. 3B). Manipulation of the tester members will permit sealing off of this plug port for removal of the plug and insertion of test instruments while maintaining the sample at reservoir conditions. Subsequently, the tester mandrel is moved to uncover the plug port and place the instruments in communication with the sample chamber for analysis of the trapped fluid.

Dilferent well testing apparatus is usually designed for use in open and cased well b o-res. While this invention is primarily directed to apparatus for testing open well bores it will be appreciated that features of the present invention can have application for testing apparatus for cased well bores.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. Apparatus in a well bore containing a well fluid for flow testing a well including,

telescopically arranged tester members movable between spaced longitudinal positions,

valve means in said tester members for controlling flow in said positions, and

packer means coupled to one of said tester members,

said packer means including telescopically mounted packer members and a packer element disposed on one of said packer members and arranged to be expanded by relative motion between said telescoping packer members,

hydraulic means for releasably holding said telescoping packer members against movement when said packer element is expanded,

said hydraulic means including a chamber formed between said telescoping packer members for receiving a hydraulic fluid,

a piston on one of said members separating said chamber into upper and lower portions,

fluid by-pass means through said piston including upper and lower passageways and a valve element controlling fluid communication between said upper and lower passageways, and

means placing said valve element in fluid communication between the interior of said packer members and the exterior of said packer members above said packer element whereby said valve element is responsive to a pressure ditferential between the pressure of the well fluid above the packer element and pressure of the formation fluid within the packer members for controlling the passage of fluid through said piston.

2. Apparatus for use in a well bore containing a well fluid for flow testing a well including,

telescopically arranged tester members reciprocally movable between spaced longitudinal positions,

valve means in said tester members for controlling flow through said tester members in said positions,

packer means including telescopically mounted packer members and a packer element disposed on one of said packer members, said packer element arranged to be expanded by relative motion between said telescoping packer members,

a piston on one of said packer members separating said chamber into upper and lower portions,

fluid by-pass means through said piston including upper and lower passageways and a valve element controlling fluid communication between said upper and lower passageways,

means placing said valve element in fluid communication between the interior of said packer members and the exterior of said packer members above said packer element whereby said valve element is responsive to a pressure differential between the pressure of the well fluid above the packer element and pressure of the formation fluid within the packer members for controlling the passage of fluid through said piston,

by-pass means between said tester members and packer members and including telescopically arranged mandrel and housing members reciprocally movable between expanded and contracted positions and by-pass valve means providing a fluid communication path between the exterior and interior of the by-pass means in one of said positions, and

means for restricting relative movement between said by-pass mandrel and housing when said by-pass members are contracted While permitting rapid movement of said by-pass mandrel and housing to said contracted position to open said by-pass valve means.

3. Apparatus for use in a well bore containing a well fluid for flow testing a well including,

telescopically arranged tester members reciprocally movable between contracted and expanded positions,

valve means in said tester members permitting fluid flow in said contracted position and preventing fluid flow in said expanded position,

packer means including telescopicaly mounted packer members and a packer element disposed on one of said packer members, said packer element arranged to be expanded by relative motion between said telescoping packer members,

a piston on one of said packer member separating said chamber into upper and lower portions,

means placing said valve element in fluid communication between the interior of said packer members and the exterior of said packer members above said packer element whereby said valve element is responsive to a pressure diflerential between the pressure of the well fluid above the packer element and pressure of the formation fluid within the packer members for controlling the passage of fluid through said piston,

by-pass means between said tester members and packer members and including telescopically arranged mandrel and housing members reciprocally movable between expanded and contracted positions and by-pass valve means providing a fluid communication path between the exterior and interior of the by-pass means in said expanded by-pass position and closing the path in said contracted by-pass position, and

4. Apparatus in a well bore containing a well fluid for flow testing a well including,

valve means in said tester members for controlling flow in said positions,

packer means coupled to one of said tester members, said packer means including telescopically mounted packer members and a packer element disposed on one of said packer members and arranged to be expanded by relative motion between said telescoping packer members,

fluid by-pass means through said piston including upper and lower passageways and :a valve element controlling fluid communication between said upper and lower passageways, and

said valve element including a cylinder opened to the well fluids in the well bore, a sliding piston received in said cylinder, and spring means for normally urging said piston toward the open end of said cylinder,

said piston having means to permit fluid flow through said upper and lower passageways connecting the upper and lower chamber in one of its positions and means for preventing fluid flow through said passage means in another position thereby trapping fluid in one of said sections.

5. Packer means including tubular, telescopically arranged members,

a packer element disposed between portions of said members and operative upon relative movement of said members to move between expanded and contracted positions,

said members having a fluid chamber formed therebetween for receiving fluid,

one of said members having a portion forming a piston in said chamber, and

means in said one member including a bypass for passing fluid through said piston,

said by-pass including valve means controlling flow through said by-pass and means placing said valve means in fluid communication with well bore fluid above said packer and the interior of said members so that said valve means is responsive to differential pressures of the well fluids and formation fluids to close said by-pass when said packer element is expanded.

*6. An apparatus for packing-off a well tool in a well bore containing a well fluid,

said apparatus including tubular, telescopically arranged members,

an expandable packer element disposed between abutment portions formed on said members and arranged to move between expanded and contracted positions in response to relative movement between said members,

one of said members having a recess therein and sealing means above and below said recess thereby forming a chamber between said members for receiving a fluid,

the other of said members having a portion sealingly received in said recess and dividing said chamber into upper and lower sections,

passage means in said other member for passing fluid between said upper and lower sections, and

valve means in said passage means for regulating the flow of fluid between said upper and lower sections and trapping fluid in one of said sections to retain said packer element in one of its positions,

said valve means including a cylinder opened to the well bore above said packer element, a sliding piston in said cylinder, and spring means for normally urging said piston toward the open end of said cylinder,

said piston having means to permit fluid flow through the passage means connecting the upper and lower chamber in one of its positions and means for preventing fluid flow through said passage means in another position thereby trapping fluid in one of said sections.

7. An apparatus for packing-off a well tool in a well bore containing a well fluid,

said apparatus including tubular, telescopically arranged members,

one of said member-s having a recess therein and sealing means above and below said recess thereby forming a chamber between said members for receiving a fluid,

passage means in said other member for passing fluid between said upper and lower sections,

valve means in said passage means for regulating the flow of fluid betwen said upper and lower sections and trapping fluid :in one of said sections to retain said packer element in one of its positions,

said valve means including a cylinder opened to the well bore above said packer element, a sliding piston in said cylinder, and spring means for normally urging said piston toward the open end of said said valve means being responsive to pressure diflercylinder, ential between the pressure of well fluids above said said piston having means to permit fluid flow through packer element when said packer is expanded and the passage means connecting the upper and lower the pressure of formation fluids to trap fluid,

chamber in one of its positions and means for pre- 5 said valve means being responsive to equalization of venting fluid flow through said passage means in pressures between the well fluids and formation fluids another position thereby trapping fluid in one of said in the well bore above and below the packer element sections, and for releasing said trapped fluid thereby releasing said restricted by-pass means for connecting said sections parts f Said relative Position to one another and permitting a slow leak of fluid 10 between said upper and lower chambers. References Cited by the Examiner 8. Apparatus for packing-off well fluids from formation UNITED STATES PATENTS fluids in a well bore,

telescopically mounted parts arranged for relative 2,711,220 6/1955 Simmons X longitudinal movement, 15 2,828,823 /1958 MOllI'lCfi 166-187 said parts having a fluid filled chamber therebetween, 2,870,846 1/1959 Moore 277116.4 X a packer element, and means for expanding and 2,982,358 5/1961 Brown 166196 X contracting said packer element by relative longi- 3,065,796 11/1962 Nutter 166-226 tudinall motion Of Said P and 3,105,553 10/1963 Chisholm 166152 X means for releasably trapping fluid in a portion of the 0 fluid chamber between the parts to retain the relative CHARLES E. OCONNELL, Primary Examiner.

position of the parts when the packer is expanded JACOB L NACKENOFF Examiner including valve means in fluid communication with the well bore above the packer element and the BR0WN,ASSi-YlanfEXl1miflerinterior of said parts, 25

Claims

5. PACKER MEANS INCLUDING TUBULAR, TELESCOPICALLY ARRANGED MEMBERS, A PACKER ELEMENT DISPOSED BETWEEN PORTIONS OF SAID MEMBERS AND OPERATIVE UPON RELATIVE MOVEMENT OF SAID MEMBERS TO MOVE BETWEEN EXPANDED AND CONTRACTED POSITIONS, SAID MEMBERS HAVING A FLUID CHAMBER FORMED THEREBETWEEN FOR RECEIVING FLUID, ONE OF SAID MEMBERS HAVING A PORTION FORMING A PISTON IN SAID CHAMBER, AND MEANS IN SAID ONE MEMBER INCLUDING A BY-PASS FOR PASSING FLUID THROUGH SAID PISTON, SAID BY-PASS INCLUDING VALVE MEANS CONTROLLING FLOW THROUGH SAID BY-PASS AND MEANS PLACING SAID VALVE MEANS IN FLUID COMMUNICATION WITH WELL BORE FLUID ABOVE SAID PACKER AND THE INTERIOR OF SAID MEMBERS SO THAT SAID VALVE MEANS IN RESPONSIVE TO DIFFERENTIAL