US2903072A

US2903072A - Apparatus for investigating earth formations

Info

Publication number: US2903072A
Application number: US536251A
Authority: US
Inventors: Mennecier Aline
Original assignee: Schlumberger Well Surveying Corp
Current assignee: Schlumberger Well Surveying Corp
Priority date: 1955-09-23
Filing date: 1955-09-23
Publication date: 1959-09-08
Anticipated expiration: 1976-09-08

Description

Sept. 8, 1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH FORMATIONS Filed Sept. 23, 1955 4 Sheets-Sheet 1 9 mm mm hmmm mm on mm m Oq mm 5 mm Nv p? It INVENTOR. MAURICE MENNECIER o'c'u BY ALINE MENNECIER A EXECUTRIX.

' ATTORNEY.

Sept. 8, 1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH F'ORMATIONS Filed Sept. 23, 1955 4 Sheets-Sheet 2 mdE K 4 t a BY EX 57 WW Sept. 8, 1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH FORMATIONS Filed Sept. 25, 1955 4 Sheets-Sheet 3 INVEN TOR. MAURICE MENNECIER DCD BY ALINE MENNECIER BY E XEOUT RIX ATTORNEY Sept. 8, 1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH FORMATIONS Filed Sept. 23, 1955 4 Sheets-Sheet 4 Maur/ce Mew/7e c/er' fl '62. B Y /4///7e Men/7 6 ever l I l l f EXECUTE/X ATTORNEY United States APPARATUS FOR INVESTIGATING EARTH FORMATIONS Application September 23, 1955, Serial No. 536,251

5 Claims. (Cl. 166-100) This invention relates to apparatus for investigating earth formations and, more particularly, pertains to a new and improved earth formation fluid sampler.

One type of fluid sampler proposed heretofore comprises a hollow projectile disposed within a gun block adapted to be lowered through a borehole to a position adjacent a formation ofinterest. At the desired level, an explosive contained by the gun block is detonated thereby to fire the projectile into the formation. The projectile is connected to a reservoir by a flexible tube and has a normally closed front aperture which is opened so that formation fluid may pass through the projectile and the flexible tube into the reservoir where it is retained by means of a check valve. The apparatus may then be raised to the surface where the sample can be recovered from the reservoir.

While the just-described arrangement may operate satisfactorily in some cases, the projectile may not al- Ways penetrate far enough into a formation of interest. Thus, the samples may be more representative of mud or mud filtrate than of any hydrocarbon in the formation. Moreover, in certain formations, such as extremely hard ones, the projectile may not remain sealed to the wall of the opening it cuts into the formation under investigation. Thus, drilling mud from the borehole may flow past theprojectile and enter its fluid-admitting opening. Obviously, if this occurs, the sample may be undesirably contaminated by the drilling mud.

It is an object of the present invention, therefore, to provide a new and improved projectile for an earth formation fluid sampler capable of penetrating far into a formation of interest to extract a sample more accurately representative of hydrocarbons.

Another object of the present invention is to provide a new and improved projectile for an earth formation fluid sampler adapted to obtain samples of formation fluids with greater reliability than heretofore possible.

A further object of the present invention is to provide a new and improved projectile for an earth formation fluid sampler which remains sealed in the opening that it cuts into a formation under investigation.

Yet another object of the present invention is to provide a new and improvedearth formation fluid sampler capable of extracting a sample of formation fluid with a greater degree of reliability than heretofore possible.

Still another object of the present invention is to provide a new and improved earth formation fluid sampler which may be employed to obtain a sample of formation fluid free of contamination by drilling mud.

.In accordance with one feature of the present invention, a projectile for an earth formation fluid sampler comprises a rear portion adapted to eifect an essentially gas-tight, slidable fit in a gun bore and a fore portion that is smaller in cross-section than the rear portion. A forward section of the fore portion is arranged to be opened to fluid flow and is adapted to be fluidly connected to a sample-conveying tube.

A projectile embodying another aspect of the invention ate-ht ice comprises a body adapted to be impelled toward a selected earth formation and having a forward section adapted to open to fluid flow. A member is connected to the body and is effectively extensible from the outer surface of the body in a zone behind the forward section, thereby to effect a fluid seal in the selected formation.

According to a further aspect of the present invention, an earth formation fluid sampler comprises a support adapted to be positioned adjacent a selected formation and having a sample-conveying conduit. Means carried by the support defines a gun bore adapted to receive a formation-penetrating projectile, a propellant for impelling the projectile toward the selected formation, and a tube. One end of the tube is connected to the projectile for entry of a fluid sample and the tube is effectively extensible from the gun bore. The fluid sampler further comprises a valve mechanism fluidly connecting the remaining end of the tube and the sample-conveying conduit. The valve mechanism has one operating condition providing a fluid communication path between the tube and the sample-conveying conduit and is transferable to a second condition in which this path is effectively closed. In the second condition, the valve mechanism is insentitive to pressure conditions in the borehole.

The novel features of the present invention are set forth with 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 reference to the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a View in longitudinal cross-section of an earth formation fluid sampler incorporating a projectile embodying the present invention, the fluid sampler being represented schematically and in one condition of operation;

Fig. 2 is a fragmentary View of a portion of the projectile represented in Fig. 1, but sholwn outside of the fluid sampler and drawn to an enlarged scale;

Fig. 3 is a view similar to the one shown in Fig. 1, but drawn to a smaller scale and illustrating the fluid sampler in another condition of operation; and

Fig. 4 is a view in longitudinal cross-section of an earth formation fluid sampler featuring another aspect of the present invention.

Fig. 5 is a perspective view of an earth formation sampler shown in a borehole traversing a number of earth formations.

In Fig. 5 there is illustrated a sampler unit 10 (excluding the projectile of the instant invention) constructed in the manner described in the copending application of R. Q. Fields filed September 23, 1955, bearing Serial No. 536,204 and assigned tothe same assignee as the present invention.

Sampler 10 shown in a borehole 13 traversing

earth formations

14, 15 and 16 containing a drilling fluid 17, such as water base or oil base mud. It is assumed that formation 15 is the one of interest from which a fluid sample is to be obtained in a manner to be more apparent from the discussion to follow.

Sampler 10 comprises a support including a cable head 10a from the lower end of which a pair of side rails 10b and extend. The lower extremities of side rails 10b and 100 are terminated by an end block 10d and a conventional centralizer 10c extends from end block 10d. The centralizer may, for example, include a plurality of bowed springs arranged in the usual manner to center the apparatus in borehole 13. An electric cable 10f extends upwardly from cable head 10a and may be employed with a winch (not shown) located at the surface of the earth to lower and raise the apparatus in the borehole in the customary manner.

Mounted between side rails b and 100 is a first sampler unit comprised of a gun block 11 positioned below a sample-receiving chamber 12. A second, similar sampler unit comprised of a gun block 11a and samplereceiving chamber 12a is mounted between the side rails below the first sampler unit. Of course, although but two sampler units have been illustrated, obviously, the side rails may be suitably extended to accommodate any desired number of additional units.

As will be more apparent from the discussion to follow, the gun blocks 12, 12a have individual gun bores each adapted to receive a formation penetrating projectile, a propellant for impelling the projectile toward the selected formation and an extensible tube having ends connected between the projectile for entry of a fluid sample and the gun bore for receipt of the sample fluid. In order to actuate or detonate the propellant in each of the gun bores,

insulated electrical conductors 10g, 1W1, lilk of cable 10f are connected to suitable igniters, one of the igniters 47 being shown in Figs. 1 and 2. A selector switch 13m is provided for selectively connecting each of the firing circuits to a source of electrical energy, such as a battery 10a which may have in a circuit therewith a rheostat 10p and a current indicating meter 10g.

In Fig. l of the drawings there is diagrammatically illustrated a portion of sampler unit 19 including the gun block 11 and the sample-receiving chamber 12. Disposed within a cylindrical, transverse bore 18 of gun block 11 is a cylindrical, hollow projectile 19 embodying the present invention. The projectile 19 has a rear end portion 20 very slightly smaller than bore 18 and an O ring 21 seated in an annular groove 22 provides a fluid seal between end portion Zil and the wall of bore 18. A tapered section 23 extends between rear portion 20 and a forward portion 24, of a smaller diameter, terminated by a generally conical formation-penetrating nose 25. By providing a forward portion 24 of reduced diameter, increased penetration may be attained.

A cylindrical chamber 26 extends through projectile 19, terminating short of nose 25, and a plurality of radial openings 27 extend between chamber 26 and the exterior surface of projectile portion 24. A tightly-fitting, slidable ring 28 receives projectile portion 24 thereby to close the outer ends of the openings 27. The ring 28 is held in place by a sleeve 29 of resilient material, such as rubber, that is tightly fitted about the ring and the adjacent surfaces of projectile portion 24 thereby constituting a retainer as well as a fluid seal for openings 27.

The rear end of projectile portion 20 has a threaded opening 30 which receives a portion 31 of a closure 32. Generally stated, the portions of the projectile thus far described constitute a cylindrical body adapted to be impelled toward a selected earth formation in a direction along a longitudinal axis 33 for the body. A portion of the closure 32 is so fabricated as to define an annular recess 34. The recess has a forward extremity 35 defined by the rear surface of projectile portion 21 in a plane transverse to axis 33 and has a rearward surface 36 of generally frusto-conical configuration inclined away from surface 35. An inner section 37 of the recess 34 is slightly enlarged to form a clamp having a projection 38 for securing an annular sealing member 39 of resilient material in the recess. Thus, an inner portion of the sealing member 39 acts as a fluid seal between

closure

31, 32 and the rear end of projectile portion 20.

The outer configuration of the sealing member 39 conforms essentially to the shape of recess 34 and it includes a forward portion 40 having a periphery essentially conforming to the peripheral dimension of section 20 of projectile 19. A rearward section 41 of the sealing member 39 is adapted to be substantially conformed to the aforesaid peripheral dimension, but, as shown in Fig. 2, is extensible to a peripheral size greater than this peripheral dimension, thereby exposing an inner surface 41. As

will be later seen, this feature permits a good fluid seal to be obtained in the selected formation.

Closure 32 is provided with an axial opening 42 for receiving one end of a flexible tube 43 to which it is mechanically connected in an appropriate manner. For example, the tube may be silver soldered to the wall of opening 42 and an enlarged head 44 is provided on the tube. Thus, the tube is fluidly sealed to the wall of opening 42, while head 44 affords a strong mechanical connection for forward movement with closure 32. Tube 43 is in fluid communication with chamber 26 and is wound into a plurality of helical turns disposed at the rear end of gun bore 18. The remaining extremity of tube 43 is fluidly connected to a conduit 45 that extends to sample-receiving chamber 12.

A propellant such as an explosive material 46 is disposed at the rear end of gun bore 18 and within the convolutions of tube 43. An electrical igniter 47 extends through a transverse opening 48 in gun block 11 into the bore 18 where it is in contact with explosive 46.

To condition the fluid sampler for operation, chamber 12 containing only air at atmospheric pressure is installed and bullet 19 is positioned in bore 18. Thereafter, the apparatus may be lowered into borehole 13. When gun block 11 is opposite formation 15, an appropriate electrical circuit is completed between a source of electrical energy (not shown) and igniter 47 thereby to detonate explosive 46 and projectile 19 is impelled out of gun bore 18 into the formation. Tube 43 uncoils and extends from the gun bore as shown in Fig. 3 thereby permitting projectile 19 to enter the formation. As the projectile enters, sleeve 29 is forced along the surface of projectile section 23, or is ruptured, thus permitting ring 28 to slide to a position adjacent projectile section 23, unblocking openings 27 to fluid flow. Accordingly, a sample of formation fluid may flow through openings 27, compartment 26, tube 43, conduit 45 and into sample-receiving chamber 12.

By providing a projectile having a forward section 24 of reduced cross-sectional area, greater penetration is secured. Furthermore, by virtue of the configuration of the outer surfaces of

portions

20, 23 and 24, an effective seal in the formation is derived. Thus, representative samples of formation fluids may be obtained.

In addition, since section 41 of sealing ring 39 tends to expand in a direction away from the outer surface of projectile section 20, it forms an effective fluid seal in the opening 49 cut into formation 15 by projectile 19. Since drilling mud 17 enters opening 49, it is in contact with inner surface 41 of sealing member 39. Hence, the pressure of the drilling mud forces the sealing member more tightly against the wall of opening 49. It is thus apparent that an eflicient fluid seal is maintained and a sample of formation fluid may be consistently and reliably taken, free of contamination by the drilling mud.

After chamber 12 is filled, unit 10 is drawn upwardly to close a valve (not shown) in the fluid path to the chamber and to break tube 43 as shown in the copending application of Fields, Serial No. 536,204. Thereafter, the unit may be raised to the surface of the earth where the sample is removed.

Although a projectile 19 having a forward section adapted to open to fluid flow in a particular way has been illustrated, obviously other types of projectiles may be employed. For example, the projectile may be arranged to open to formation fluids in the manner described in any of the following applications which have been assigned to the same assignee as the present invention: application Serial No. 536,189 of Maurice P. Lebourg and Roger Q. Fields, filed September 23, 1955; application Serial No. 536,190 of Andre Blanchard, filed September 23, 1955; and application Serial No. 536,115 of Maurice P. Lebourg, filed September 23, 1955.

By appropriately selecting the shape and length of pointed nose 25, it can serve to push aside any mud cake '5 that might be present on the wall of borehole 13. This isespecially useful in arrangements wherein the very foremost-position of the projectile opens to fluid flow, as disclosed in the copending applications just mentioned.

If desired, tube 43 may be filled with a relatively incompressible liquid prior to operation of the fluid sampler. For example, water, alcohol, mercury, or a silicon fluid DC. 200 may be employed. In this way, a thinner-walled tube can be used while withstanding the force of the explosion of explosive 46.

In Fig. .4 the earth formation fluid sampler constructed in accordance with another aspect of the present invention is shown to comprise a sampler unit including a g n block11' and a sample-receiving chamber 12'. It

be observed that gun block 11' has its bore 18' inclined downwardly at an angle to a horizontal plane. Thus when the propellant is ignited by connecting an appropriate source of electric current to igniter leads 50 that extend to the surface of the earth, a projectile 51 is impelled toward the sidewall of borehole 13' and enters at an angle other than 90.

As an alternative to the construction shown in Figs. 1 and 3, the fore portion 52 of the projectile may be arranged to minimize compaction of material in earth formation as disclosed, for example, in the aforementioned copending application of Maurice P. Lebourg and Roger Q. Fields. To this end, the projectile has an opening 53 normally closed by a plug 54 which is driven into a chamber 55 upon impact with formation material. The projectile is thus opened to admit formation fluids which may flow through a filter 56 and into a flexible tube 43' that is mechanically connected to a closure 57 for the rear end of bore '18 in gun block 11'.

The fluid path between tube 43 and sample-receiving chamber 12 is completed via a conduit 58 in closure 57, a conduit 59 in gun block 11, a flexible tube 60 and a valve chamber 61. In valve chamber 61 there is disposed an indicator valve comprised of a pivoted vane 62 of electrically conductive material having a contact 63 at its free end normally in engagement with a fixed contact 64. Thus, when fluid flow occurs, an electrical circuit between a lead 65 that extends to the earths surface and the con ductive material of valve chamber 61 is interrupted.

Also disposed in valve chamber 61 is an electrically operated valve 66 having a bore 67 in which a plunger 68 is slidably positioned. Bore 67 is in fluid communication with chamber 12 via a port 69 and with chamber 61 via a side port 70. A spring 71 normally holds plunger 68 in engagement with a seat 72, thereby interrupting fluid communication between ports 69 and 70. However, plunger 68 has an extension of magnet material disposed in operative relation with a solenoid coil 73 connected to a pair of conductors 74 which extends to the surface of the earth. Accordingly, when the solenoid 73 is energized, the plunger 68 is drawn downwardly and fluid from the formation may flow into chamber 12'. After the sample is received, the circuit to solenoid 73 is opened and the valve 66 closes. Thus, in a sequence of operation described above in connection with Fig. 3, when tube 43 is broken, the sample in chamber 12' cannot be contaminated by drilling mud 17.

A sealed chamber 75 houses a pressure-measuring device which may be in the form of a pressure bomb. This type of pressure gauge comprises a piston 76 slidably movable in fluid sealed relation through an opening 77 in a common partition for chambers 12' and 75. The piston is exposed to the pressure in chamber 12' and is biased in a direction opposite to movement due to pressure by a spring 78. A stylus 79 bears against a chart 80 that is driven continuously during operation of the sampler by a clock mechanism 81. Thus, a continuous record of the pressure of fluid in chamber 12' may be obtained during an entire cycle of operation.

If desired, the open end of gun bore 18 may be pro vided with a sharpened edge 82 so that the tube 43' may 6 be sheared more easily when the sampler unit 10" is drawn upwardly. An additional shear point may be provided by appropriately weakening a portion of closure 57, for example at point 83.

By suitably magnetizing or radioactivating the projectile that is subsequently left in the formation, it may serve as a depth-marker in a well-known manner.

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.

I claim:

1. In an earth formation fluid sampler, a projectile comprising: a hollow body adapted to be impelled toward and into a selected earth formation in a. direction along an axis for said body and including a fluid-admitting forward section of a predetermined cross-sectional area in a plane transverse to said. axis and a rearward section of a cross-sectional area in a plane transverse to said axis larger than said predetermined cross-sectional area and having an annular recess; and an annular sealing member of resilient material secured within said recess and including a forward portion having a periphery essentially conforming to the peripheral dimension of said rearward section of said body and a rearward section compressible to conform substantially to said peripheral dimension, but normally extended to a peripheral size greater than said peripheral dimension to elfect a fluid seal in the selected formation.

2. In an earth formation fluid sampler, a projectile comprising: a cylindrical body adapted to be impelled toward a selected earth formation in a direction along an axis for said body and having an annular recess, said recess having a forward extremity defining a plane transverse to said axis and a rearward surface of frusto-conical configuration inclined away from said forward surface; and an annular sealing member of resilient material having an inner section secured within said recess and an outer section essentially conforming to the configuration of said recess, said sealing member further including an outer surface normally of frusto-conical form having a forward section substantially conforming to a surface defined by the outer extremity of said body and having a rearward section extending from said last-mention surface, but said member being deformable to conform substantially entirely to said last-mentioned surface.

3. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation and having a sample-conveying conduit; means carried by said support and defining a gun bore; a formation-penetrating projectile disposed within said gun bore and having normally closed sample-admitting opening adapted to be opened to fluid flow after said projectile is imbedded in the selected formation; a propellant disposed within said gun bore for impelling said projectile toward the selected formation and into the formation so that the projectile is physically separated from said support; a flexible tube having one end connected to said opening of said projectile for entry of a fluid sample and effectively extensible from said gun bore; a relatively incompressible liquid filling said tube; a fluid conduit connecting the remaining end of said tube and said sampleconveying conduit; and a valve mechanism in said fluid conduit.

4. In an earth formation fluid sampler, a projectile comprising: a body adapted to be impelled toward and into a selected earth formation and including a forward section and a rearward section, said forward section having a hollow chamber adapted to receive formation fluid, said rearward section having an annular recess; an annular seal-ing member of resilient material disposed in said recess having an outer surface of frusto-conical form and an inner surface with a portion thereof with a frusto-conical form, said inner and outer surfaces defining an acute angle therebetween, the forward portion of said sealing member substantially conforming to the surface of said rearward section and the rearward portion of said member extending outwardly of said last-mentioned surface.

5. In an earth formation fluid sampler, a projectile comprising: a body adapted to be impelled toward and into a selected earth formation and including a forward section and a rearward section, said forward section having a hollow chamber adapted to receive formation fluid, said rearward section having an annular recess; an annular sealing member of resilient material disposed in said recess having an outer surface of frusto-eonical form and an inner surface with a portion thereof with a frusto-conical form, said inner and outer surfaces defining an acute angle therebetween, the forward portion of said sealing member substantially conforming to the surface of said rearward section and the rearward por- 8 tion of said member extending outwardly of said lastmentioned surface, said resilient member being deformable in said annular recess to conform substantially entirely to said last-mentioned surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,055,506 Schlurnberger Sept. 29, 1936 2,119,361 Schlumberger May 31, 1938 2,303,727 Douglas Dec. 1, 1942 2,381,929 Schlumberger Aug. 14, 1945 2,441,894 Mennecier May 18, 1948 2,545,306 Pollard Mar. 13, 1951 2,632,512 Chaney et a1 Mar. 24, 1953 2,674,313 Chambers Apr. 6, 1954 2,678,804 Lebourg May 18, 1954 2,799,347 Wilcox July 16, 1957 OTHER REFERENCES Ser. No. 271,524, M. Schlurnberger (A.P.C.), published May 25, 1943.

Claims

4. IN AN EARTH FORMATION FLUID SAMPLER, A PROJECTILE COMPRISING: A BODY ADAPTED TO BE IMPELLED TOWARD AND INTO A SELECTED EARTH FORMATION AND INCLUDING A FORWARD SECTION AND A REARWARD SECTION, SAID FORWARD SECTION HAVING A HOLLOW CHAMBER ADAPTED TO RECEIVE FORMATION FLUID, SAID REARWARD SECTION HAVING AN ANNULAR RECESS; AN ANNULAR SEALING MEMBER OF RESILIENT MATERIAL DISPOSED IN SAID RECESS HAVING AN OUTER SURFACE OF FRUSTO-CONICAL FORM AND AN INNER SURFACE WITH A PORTION THEREOF WITH A FURS-