US2784786A

US2784786A - Formation testing apparatus

Info

Publication number: US2784786A
Application number: US364463A
Authority: US
Inventors: John E Walstrom
Original assignee: California Research LLC
Current assignee: California Research LLC
Priority date: 1953-06-26
Filing date: 1953-06-26
Publication date: 1957-03-12
Anticipated expiration: 1974-03-12

Description

2 Sheets-Sheet l Filed June 26, 1953 March 12, 1957 J. E. WALSTROM 2,734,786

FORMATION TESTING APPARATUS Filed June 26, 1953 2 Sheets-Sheet 2.

IIIIII IIIIII IIII I IIIIIII' .Im" A iI I INVENTOR JOHN E. WA TROM drill pipe in the hole.

United States Patent() FORMATION TESTING APPARATUS John E. Wals trom, Diablo, Califl, assignor, by mesne assignments, to California Research Corporation, San Francisco, Calif., a corporation of Delaware Application June 26, 1953, Serial No. 364,463

4 Claims. (Cl. 166-3) The present invention relates to apparatus for withdrawing fluid samples from earth formations traversed by a bore hole, more particularly to apparatus for sampling fluid content of a formation through the side wall ofthe borehole traversing said formation, and has for an object the provision of an improved apparatus for ropen-hole 'samplingin si-tu of the fluids containedin earth formations by rupturing or piercing the formation while controlling the lateral thrust of a body member of a sampling device against the formation to be tested to maintain a seal therebetween, both before and during 'at a considerable distance above the bottom of the bore hole.

Heretofore, suchoflbottom testing for fluid content has only been possible under somewhat limited circumstances.

One of the methods commonly used includes the use of a pair of full-hole packers positioned above and below thejformationto be tested. Thedifficulty with this type of testing, also known as straddle-packer testing,"lies in a small clearance available between thepackers and the walls of the bore hole due to thelimitedexpandability of the packers. In commercial practice, it has been found fthat'packers can only be expandedin diameter about one inch, where the diameter of the hole is in thejrangeof seven to nine inches. Where the formation to be tested lies at a depth of several thousand feet, such small clearance introduces a very serious hazard of sticking the Another serious limitation in the use offull-hole, strad- 'dle" packers lies in the fact that such straddle packers can only be set relatively near the bottom of the hole.

Where a formation of interest lies more than a very few hundred feet off bottom, it is generally necessary to 7 land a plug in the well bore below the formation to, be

tested upon which the drill pipe may be seated in order to expand a single full-hole packer above the test formation. In practice, it has been found that a testing tool upon which a packer is run into the hole may slip off such a plug or the plug may be pushed down the hole, and in some instances theplug may leak. Additionally, it is not desirable toplug the hole if total depth has not been reached in the drilling of the well. In some instances delayed testing until total depth has been reached may render the formation subject to severe damage by mud, or the formation may be damaged by caving or sloughing,

while the drilling is continued. Thus, a potentially-productive formation may be lost entirely if the formation is not testeduntil a subsequent date.

Alternativeto the foregoing methods of testing a formation is the so-called drill stem test in which at predetermined intervalsthe'drilling tool is withdrawn and are- A rection of 'arrows3- -3 inFig. 2.

Patented Mar. 12,1957

"ice

normal drilling operation at regular depth intervals to drill a reduced diameter hole. Subsequent reaming of the hole is required to reach full-hole size. Furthermore, the predetermined depth interval may often prevent testing of a particular part of the interval, without setting of bottom plugs.

The third alternative available heretofore in commercial practice, and by far the most expensive, involves the setting of casing in the well bore with subsequent piercing of thecasing,'as in normal oil-well completion practice. This method is so expensive that it is normallyfollowed onlywhen the indications'of a producing formation are extremely good. On what is considered arnarginal show of oil orgas in "the well, the setting of casing and completion of the well to test the show is often considered so unattractive that it is not employed. However, should the show have been improperly evaluated as being marginal, a valuable well or field may be abandoned.

In accordance withthe present invention there is provided an apparatus for open-hole formation testing for fluid content which may be'used at any timeafter the drilling of a well by conventional drilling procedures. Further, the formation fluid content maybe sampled in adequate volume to obtain a true representation of the fluid in accordance with the invention by supporting the testing apparatus adjacent the formation on drill pipe. In a preferred form of apparatus, thebody member is provided with means for forcing a portion of the body into engagement with the side of the bore hole, which includes a pivotally-mounted leg-member adapted to engage the opposite side of the bore hole and so pivoted with respect to the body thatthe lateral thrust of the body member againstthe formation may be controllably adjusted by regulating the weight of .that portion of the drill pipe which is supported between the leg member and the portion of the body member in contact with the formation. Means for piercing the portion of the body member in engagement withthe formation, as wellas the formation, is provided within the body of the testing .tool, and flow passages between the formation and the drill pipe are provided to permit formation fluids .to rise tion'taken in conjunction with the accompanying drawings which form an integral part of the present specification.

In the drawings, Fig. l is a diagrammatic representation of a preferred form of the present invention illustrating the manner in which the testing tool is supported in the well bore and controllably brought into contact with the formation whose fluid content is to be tested.

Fig. 2 is an enlarged cross-sectional view of the lower end of the testingtool illustrated in Fig. 1.

i Fig. 3 is a side view of the, testing tool "taken in thedition of arrows 6-6 in'Fig. 2 particularly illustrating the formation-engaging face portion of the testing tool and the means for piercing said face and the adjacent format-ion.

Fig' 7 is a side elevation view in the direction of arrows 7+7 in Fig. 2 particularly illustrating a preferred form of the face-engaging portion of the testing tool. a

With reference to the drawings, and in particular Fig. 1, there is illustrated a preferred form of apparatus for carrying out the present invention, in which a fluid sampling tool 10 for sampling the fluid content of a formation 1 1 traversed by bore hole '12 is adapted to be supported in the bore hole by a stand of drill pipe indicated generally as 13, which, in turn, is supported by drilling derrick 14 including traveling block 15 and crown block 16 through cable 17. As will be understood by those skilled in the art, drill pipe 13 may be raised and lowered in the bore hole by cable 17 operating through traveling block 15 and crown block 16 by reeling and unreeling the cable on drum 218. The weight of the drill pipe 13 is arranged to be recorded or indicated by dead weight indicator 19, which is interposed between the anchor means 20 and the deadwire 'line 21, which forms an extension of the end of cable 17 passing downwardly from crown block 16.

In accordance with the present invention, during rupture of the formation and withdrawal of fluid therefrom the weight indicating means 19 and the pipe supporting means,

including derrick 14 and cable 17, provides a means for controlling the lateral thrust of the face or formationengaging portion of the body 26 of the fluid sampling tool 10 against the wall of the bore hole. The lateral thrust of face portion 25 against formation 11 is provided by a combination of the vertical weight of drill pipe 13 and laterally-extending leg member 28. In the present arrangement, leg 28 is pivoted at 29 and brought into engagement with the wall of bore hole '12 by spring member 30. The function of wedging leg 28, when the weight on testing tool 10 is increased by decreasing the tension on pipe 13 and cable 17, is to exert a lateral thrust of predeterminable value between face 25 and the side wall of bore hole 12 opposite the formation which is to be tested.

As more fully illustrated in Figs. 2, 6 and 7, the face portion 25 for engaging the formation whose fluid content is to be tested may comprise a plug member threadably engaging the body member 26, which is provided with a chamber 36 for positioning an explosive for piercing the formation, such as shaped charge 37, in a portion 38 of plug 35 which is ruptured or pierced by explosive detonation of charge 37. In the preferred embodiment of the invention, portion 38 forms a hold-back plate to permit shaped charge 37 to increase its piercing depth into formation 11 when detonated by the dropping of a go-devil through pipe 13 to contact blasting cap 40. Prima cord which may be brought into firm contact with the formation wall by piercing through the mud cake, as shown in Fig. 6, which normally surrounds the periphery of bore ,hole 12. To assist in the ready removal and insertion. of

plug 35 into body member 26, plug 35 may be provided with aplurality of spanner wrench-engag-ing holes 47. As mentioned hereinabove, tool 10, and. the face portion thereof, is brought into engagement with the side wall of bore hole-12 with a controllable thrustbytthe vertical action of the weight of drill pipe 13 acting through wedging leg 28 and pivot 29 by which leg 28 is connected to extension 51 of body member 26.

Since it is desirable to maintain as small as possible the total diameter of the drill pipe 13 and the testing tool run into hole 12, provision is made for maintaining the wedging leg 28 in a restrained position against the action of spring 30, as partially illustrated in Fig. 2 and more fully shown in side elevation, Fig. 3. As illustrated in these figures, leg 28, including the side wall engaging portion 50, is held by a transverse pin 52 within the housing 51, which forms a lower extension of body member 26. Pin 52 is of the shear type which may be severed by knife edges 53 being moved upwardly by bull-nose plug 55 being raised against biasing spring 56 when the weight of the drill pipe in body member 26 is brought to bear thereon by lowering the entire tool to the bottom of the drill hole. Upon severance of the shear pin 52, wedging leg 28 is forced outwardly into the position shown in Fig. 1 and partially illustrated in Fig. 2 by biasing spring 30. 'A stop member 58 may be provided above wedging arm 28 to prevent arm 28 from pivoting above the horizontal in the event that a cavernous formation is encountered during the withdrawal of the tool from the well bore. It will be apparent that the length of wedging leg 28 may be made such that the tool may be employed even where cavernous formations are encountered by extending the length of the 'leg. Y After completion of the test, provision is made for shutting oh? the communication between the formation and drill pipe 13 through

fluid passageways

60 and 72 which formed the ignition path between cap 40 and charge 37. Such shut-off is made by rotation of collar member 61 which forms an upward extension of testing tool 10 adapted to engage the lower end of drill pipe 13. As particularly illustrated in Fig. 2 rotatable collar 61 is secured through screw 62 to a ring member 63 fitted within an upwardly-extending and flanged portion 65 of the body portion 26. Collar member 61 is preferably provided with recessed portion of arc-like configuration adapted to engage a pin member 71, best seen in Fig. 4, mounted upon the upper end of extended portion 65 of body 26. By rotation of drill pipe 13 and collar member 61 fluid flow passageway 72 in collar 61 may be rotated into the dotted line position, designated as 73, before the tool is lifted to withdraw the face of the testing tool away from the sampled formation. d

In operation of the present invention, particularlylthe form thereof illustrated in the drawings, the testing tool 10 is assembled, as illustrated in Fig. 2, and run into the hole with the pipe 13 maintained substantially dry. The tool is then lowered until the bottom of the well bore is reached, at which time the weight of the drill pipesupported by derrick 14 is decreased as indicated on weight indicator 19, thereby to shear holding pin 52 to permit wedging leg 28 to rotate outwardly into engagement with the wall of well bore 12. The pipe and testing tool are then raised in the well until the tool is opposite the formation whose fluid content is to be tested, such as formation 11. At that time the combined weight of the tool and drill pipe supported by derrick 14 and cable 17 is again decreased to a predetermined degree as measured by weight indicator 19. This action causes the lateral thrust between face 25 and formation 11 to be increased to a degree adequate to assure a firm sealing between the face of the formation and the face of the testing tool. A godevil is then dropped through drill pipe 13 to detonate blasting cap 40, prima cord 41, and charge 37. Upon detonation of these explosives the formation face is ruptured and the fluid flow path through chamber 36,

passageway

60 and 72 cleared for the upwardflow of fluid from within formation 11 into pipe 13.

After the passage of adequate time for fluid content to rise through body 26 into drill pipe 13, the drill pipe may be rotated in a clockwise direction-as seen Figs. 4

and ,5, to close communication between passageways 72 and passageway 64) and the tool lifted to release the lateral thrust between the face of the formation and the portion of the body member in engagement therewith and the entire assembly withdrawn from the well for removal of the fluid sample.

From the foregoing detailed description, it will be apparent that in accordance with the present invention there is provided a fluid sampling apparatus for testing the content of a formation traversed by a bore hole, in which the contact between the body member and the formation may be maintained through the application of a controllable amount of lateral thrust introduced by the vertical weight of the drill pipe acting through a side wall engaging leg both before, during, and after the piercing or 111pturing of the formation and the withdrawal of fluid sample from the formation.

Various modifications and changes in the foregoing apparatus will occur to those skilled in the art without departing from the scope of the present invention. In particular, the face-engaging portion of plug 35 may be adapted to provide other forms of sealing faces particularly adapted to the type of formation Whose fluid is to be sampled. It will also be apparent that a plurality of face-engaging similar to the single one illustrated in the drawings may be brought into contact with the face of the Wall simultaneously and fluid withdrawn through each of the face portions. While a shaped charge for piercing the formation has been illustrated and described, other forms of gun perforating apparatus may be employed which may be detonated by concussion or electrical energy.

Other modifications and changes may be made without departing from the scope of the appended claims, and all such modifications falling within the terms of said claims are intended to be included therein.

I claim:

1. Open-hole fluid sampling apparatus adapted to be lowered into an open bore hole on a length of drill pipe comprising a body member connected to said drill pipe and movable relative thereto, said body member having a laterally disposed face adapted to engage the side wall of an open bore hole, a wedging leg pivotally connected to said body member below said laterally disposed face, said leg including biasing means for forcing the opposite end of said leg extending below said pivot point into engagement with the side wall of said bore hole opposite a formation whose liquid content is to be sampled, means for applying at least a portion of the weight of said drill pipe to said leg to wedge said opposite end of said leg into engagement with said bore hole wall to pivot said body member about the point of engagement of said leg with said bore hole wall for forcing said face into firm engagement with said bore hole wall, a sample-receiving chamber in said drill pipe, rupturing means for rupturing said face and said formation, and cooperating fluid passage means in said body member and in said drill pipe for establishing fluid communcation to said sample chamber from said ruptured face to permit flow from said formation through said ruptured face to said sample chamber, said communicating passage means being adapted to be closed in response to relative movement between said body member and said drill pipe upon completion of the sampling to trap said formation fluid in said sample chamber.

2. Open-hole fluid sampling apparatus adapted to be lowered into an open bore hole on a length of drill pipe comprising a body member connected to said drill pipe and movable relative thereto, said body member having a laterally disposed face adapted to engage the side wall of an open bore hole, a wedging leg pivotally connected to said body member below said laterally disposed face, said leg including biasing means for forcing the opposite end of said leg extending below said pivot point into engagement with the side wall of said bore hole opposite a formation whose fluid content is to be sampled, means for applying at least a portion of the weight of said drill pipe to said leg to wedge said opposite end of said leg into engagement with said bore hole wall to pivot said body about the point of engagement of said leg with said bore hole wall for focusing said face into firm engagement with said bore hole wall, a sampling-receiving chamber in said drill pipe, explosively-actuated rupturing means within said body member and adjacent said face for rupturing said face and said formation, cooperating fluid passage means in said body member and in said drill pipe for establishing fluid communication to said sample chamber from said ruptured face to permit fluid flow from said formation through said ruptured face to said sample chamber, explosive cap means in the lower portion of said sample-receiving chamber of said drill pipe, and explosive cord means extending through said cooperating fluid passage means for connecting said cap means to said rupturing means, said communicating passage means being adapted to be closed in response to relative movement between said body member and said drill string up on completion of the sampling to trap said formation fluid in said sample chamber.

3. Open-hole fluid sampling apparatus adapted to be lowered into an open bore hole on a length of drill pipe comprising a body member connected to said drill pipe and having at least a portion thereof rotatable relative to said drill pipe, said rotatable portion of said body member having a laterally disposed face adapted to engage the side wall of an open bore hole, a wedging leg pivotally connected to said rotatable portion of said body member below said laterally disposed face, said leg including biasing means for forcing the opposite end of said leg extending below said pivot point into engagement with the side wall of said bore hole opposite a formation whose fluid content is to be sampled, means for applying at least a portion of the weight of said drill pipe to said leg to wedge said opposite end of said leg into engagement with said bore ho-le wall to pivot said body member about the point of engagement of said leg with said bore hole wall for forcing said face into firm engagement with said bore hole wall, a sample-receiving chamber in said drill pipe, explosively-actuated rupturing means within said body member and adjacent said face for rupturing said face and said formation, and cooperating fluid passage means insaid rotatable portion of said body member and in said drill pipe for establishing fluid communication to said sample chamber from said ruptured face to permit fluid flow from said formation through said ruptured face to said sample chamber, said communicating passage means being adapted to be closed by rotation of said drill pipe while said rotatable portion of said body member is in contact with said bore hole wall and upon completion of the sampling to trap said formation fluid in said sample chamber.

4. Open-hole fluid sampling apparatus in accordance with claim 3 including explosive cord means for igniting said explosively-actuated rupturing means extending from said sampling-receiving chamber in said drill pipe to said rupturing means through said cooperating fluid passage means, said cord means resisting rotation of said rotatable portion of said body member with respect to said drill pipe and preventing rupture of said face by said rupturing means if said cord means has been severed by closure of said cooperating passage means by rotation between said body member and said drill pipe, and means for igniting said explosive cord means in said sample-receiving chamber of said drill pipe.

References Cited in the file of this patent UNITED STATES PATENTS 2,173,532 De Long Sept. 19, 1939 2,313,369 Spencer Mar. 9, 1943 2,528,883 Hayward Nov. 7, 1950 FOREIGN PATENTS 852,386 Ger-many Oct. 13, 1952