US2740477A

US2740477A - Apparatus for obtaining fluid samples from subterranean formations

Info

Publication number: US2740477A
Application number: US253644A
Authority: US
Inventors: Richard J Monaghan
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-10-29
Filing date: 1951-10-29
Publication date: 1956-04-03
Anticipated expiration: 1973-04-03

Description

Apnl 3, 1956 R. J. MONAGHAN 2,740,477

APPARATUS FOR OBTAINING FLUID SAMPLES FROM SU'BTERRANEAN FORMATIONS Filed Oct. 29, 1951 2 Sheets-Sheet l A32 1 .34 I 5 i Q39 4+ '38 i7 4 $2.9 T 37 A 30 l if yak 1 46 46' y i 7 /9 T /E a L l 9 6 B. 7 INVENTOR iii a ,3 A E/CHAEDJMONAGHAN 2, BY z); a 4 ATTORNEYS April 3, 1956 R. J. MONAGHAN 2,740,477

APPARATUS FOR OBTAINING FLUID SAMPLES FROM SUBTERRANEAN FORMATIONS Filed Oct. 29, 1951 2 Sheets-Sheet 2 ATTORNEYS United States Patent 9 APPARATUS FfiR OBTAINING FLUID SAMPLES FROM SUBTERRANEAN .FORMATIONS Richard 3. Monaghan, Baton Rouge, La.

Application October 29, 1951, Serial No. 253,644

11 Claims. (Cl. 166-63) This invention relates to means for obtaining, during oil well drilling operations, samples or specimens of formation fluid as it exists in the earths formation immediately below the bottom of the oil well being drilled.

It is a prime object of the present invention to provide for conveniently and effectively obtaining such samples or specimens of formation fluid in its natural condition uncontaminated by drilling fluid which is commonly employed in well drilling operations.

it is an object of the invention to provide for excluding drilling fluid from an area of the bottom end wall of the oil well and forming an opening through said area and a cavity in the formation therebelow, so that there will be no opportunity for the drilling fluid to enter through the top of the cavity during the formation thereof.

It is a further object of the invention to provide for removing formation fluid from the cavity and trapping it in its natural physical condition uncontaminated by drilliug fluid.

Another object of the invention is to provide for sealing the top of the cavity as an added precaution against ingress of drilling fluid and also to prevent escape of formation fluid therethrough, thus preventing the well from becoming active.

It is another object of the invention to provide a tool or instrument for accomplishing the foregoing stated objects in such a form that it may be lowered through a drill string during drilling operations.

It is a further object of the invention to provide for effectually inserting the collecting nozzle of the device into the cavity and for withdrawing it therefrom.

It is a further object to provide for forming the opening through the bottom end wall .of the well and the cavity in the underlying formation by the effect of an explosion applied directly against the bottom end wall of the well. Specifically it is proposed to use a so-called shaped charge for this purpose.

Additional objects and advantages of the apparatus of this invention will become apparent from the following specification and claims taken in connection with the accompanying drawings, in which- Figure 1 is a view, partly in elevation and partly in vertical section, of one embodiment of the device or tool of the present invention and as designed for carrying out the invention shown in its initial position within the drill string.

Figure 1 is a view in vertical section of the top part of the device showing the connection thereof with a drill string.

Figure 2 is an enlarged view in vertical section of the lower part of the device in engagement with the bottom end wall of an oil well in position for excluding drilling fluid from an area thereof.

Figure 3 is a detail fragmentary vertical sectional view of the lower part of the device with the collecting nozzle in position to receive formation fluid and lead the same into the trap chamber.

2,740,477 Patented Apr. 3, 1956 Figure 4 is a vertical fragmentary sectional view of a detail.

Figure 5 is a detail vertical fragmentary view of the device showing parts in position immediately prior to firing the explosive charge.

Figure 6 is a cross sectional view taken on the line 6-6 of Figure 5.

Figure 7 is a detail vertical sectional view taken through the top of the lower or barrel member of the device.

Figure 8 is a cross sectional view on the line 8-8 of Figure 1.

Figure 9 is an enlarged detail fragmentary sectional view of one half of Figure 7 and at right angles thereto.

Figure 10 is a vertical sectional view taken through the breech block members and showing the passage therebetween.

The tool or instrument of the present invention is designed for lowering an explosive charge through a drill string and bit into cooperative relation with the bottom end wall of the well and to provide for firing the explosive directly against said wall for the purpose of burning or blasting an opening in said wall and a cavity in the underlying formation. It is also designed for sealing off a selected area of the said wall through which the opening is to be formed or in other words, for excluding drilling fluid from such area during the formation of the opening and the cavity prior to the firing of the charge.

In Figure l of the drawings, a vertical section of an oil well bore C has ben shown in which is a core drill bit F secured by a screw threaded connection to the bottom end of a drill collar E. The drill bit has been shown as being in a retracted position a few feet above the bottom end wall of the well. The device or tool of the present invention has been shown in this figure in the position in which it is placed prior to exploding the charge employed for forming an opening through the bottom wall of the well as shown in Figure 2 of the drawings.

The device for carrying out the present invention is either dropped through a drill string, which is of course full of drilling fluid, or it is lowered through the drill string in much the same manner as wire line coring equipment. The device floats downwardly through the drilling fluid in the drill string and finally comes to rest in the position shown in'Figure 1 wherein the descent of the tool has been stopped by an external annular shoulder 40 thereon engaging an internal annular shoulder 41 within the drill collar.

For convenience in lowering the device or tool, I propose to use an ordinary or preferred form of 'wire line overshot 26 as shown in Figure 1 of the drawings, suitably connected to the top of the present tool, as will be explained hereinafter.

One embodiment of the device or tool of the present invention has been shown in the accompanying drawings and includes a lower member A which is here shown as being an open ended tube or cylindrical barrel, and an upper member 'B here shown as substantially cylindrical in shape, and telescoped within the member A, and provided with a packing ring 6 to prevent leakage of drilling fluid between the members A and 'B. As shown, the member B is provided with a longitudinally disposed chamber 1 closed at its bottom end as best shown in Figure 2. A longitudinally disposed passage '2 extends from the lower closed end of the chamber 1 downwardly through the lower end of the member .3 which passage fluid which the present tool is intended to collect or obtain from below the bottom end wall of an oil well. In order that a larger quantity of formation fluid may be accommodated in the present tool than can be held in the chamber 1, the member B may be made in two sections, a lower section B and an upper section B" suitably connected to the open top of the member B, as by screw threads, shown in Figure 1. This section B" may be provided with a chamber 1', shown in Figure 1, open at its upper end so as to communicate with and form a continuation of the chamber 1. However, it will of course be understood that it is not necessary to make the member B in two sections.

As best shown in Figure l of the drawings, the upper portion of the member B is reduced in diameter as at 3', thereby forming an upwardly facing annular shoulder 5 at the base of the reduced portion, which shoulder is designed to normally engage upwardly against an internal annular shoulder on the member A preferably formed by the bottom end of a bushing s screwed into the open top of the member A. The bore of the bushing 6' is provided with a plurality of open ended groves to slidably receive longitudinal ribs 7 on the reduced part 3 of the member B so as to center and guide the member B within the member A for a purpose as will be hereinafter explained. A helical spring 8 embraces the reduced part 3' of the member B. Its lower end bears downward against the top of the member A formed by the bushing 6 and its upper end bears upwardly against an annular shoulder on the reduced part 3 which shoulder in the present em- Y bodiment of the invention, is the bottom of the upper section B. Where the member B is not made in two or more sections a suitable shoulder or bearing may be provided upon the reduced part 3 for the upper end of the spring 8 to bear against. This spring normally holds the annular shoulder 5 of the part B against theannular shoulder provided by the lower end of the bushing 6 and thereby prevents endwise separation of the parts A and B.

At the bottom of the open end of the barrel or member A there is a tubular section 9 open at its lower end and provided at its upper end with a reduced externally screwthreaded stem It engaging the internally screw-threaded portion of the lower end of the member A. The lower end of the member 9 is provided with a packing ring 10', preferably of compressible material, seated in a recess formed in the outer face thereof. The ring 10 is arranged with the lower edge thereof flush with the lower edge of the member 9 and the outer face thereof flush with the outer face of said member. This section 9 constitutes a chamber for holding an explosive charge 11, provided in one end with a preferably conical recess 12 and positioned in said chamber with the open end of said recess presented downwardly. For holding and centering the charge, within the section or hell 9, there is an annular gland or nut 13 which may be entered through theopen lower end of the bell 9, and engaged with an internally screwthreaded part of the bell. The inner wall of the gland 13 is inclined upwardly and. outwardly and engages the lower edge of the charge to force the same into engagement with the upper concave inner wall 14 of the bell 9 to center said charge within the bell.

At suitable distance above the top of the bell section 9, there is an internal nut 15 engaging an internally screwthreaded part of the member A and provided with a centrally disposed opening or passage 16 which is preferably flared at its upper end as at 17. This opening 16 constitutes a seat for a detonator or percussion cap 18 employed for setting off the charge 11. Frictionally held between the top of the bell section 9 and the nut 15 are a pair of breech block members 19 mounted to slide diametrically within the member A. As best shown inFigures 6 and 9, these breech blocks are provided with grooves 20 which, when the breech blocks are brought together will match and form a zigzag opening or passage best shown in Figure 9 through which the flash or fire from the detonator or percussion cap 18 may pass to the charge 11. The top of the bell section 9 is provided with an opening 21 through which the flash 0r fire may pass from the passage 29 to the explosive charge.

For firing the detonator or percussion cap, there is provided a firing pin 22 carried by and projecting downwardly from the member B in the longitudinal center line of the member A so as to engage the percussioncap or detonator as will be best understood by reference to Figure 5 of the drawings. Upon downward movement of the firing pin 22, after it has engaged and detonated a percussion cap, it will pass on downwardly through the opening 29 between the breech blocks forcing them apart so that the firing pin may continue on downwardly through the opening 21 and further downwardly through the interior of the bell formerly occupied by the shaped charge prior to the explosion thereof. Closing the open bottom end of the out or gland 13 is a hood member 23 suitably secured thereto for the purpose of preventing upward passage of drilling fluid into the interior of the bell 9 and against the shaped charge 11. This member 23 is of suitable material, strong enough to resist the pressure of drilling fluid but capable of being broken or destroyed by the effect of the explosion of the explosive charge, and therefore the firing pin 22 may pass on downwardly through and beyond the open lower end of the member A when the hood 23 has been destroyed or ruptured, The firing pin is provided with a longitudinal bore or passage 24, the upper end of which communicates with the passage 2,in the bottom end of the member B. The lower end of the firing pin is preferably pointed as shown, to ensure a proper detonation of the percussion cap, and a plurality of passages 25 areprovided through the firing pin so as to atford communication between the exterior of the pin and the passage or bore 24, whereby formation fiuid as hereinafter explained, may pass into the passage 24 and upwardly therethrough into the chamber 1' within the member B. p

In lowering the device or tool through a drill string, the procedure is much the same as in the well known wire line coring method. A wire line overshot 26 is secured to the upper end of the present device as by a screw threaded connection 27. Within a socket or chamber 28 in the part 26 is mounted an upright dog 29 pivoted at its lower end as at 30 so that it may swing diametrically of the part 26 through a slot 31 disposed vertically through the part 26 and through which slot the dog may project beyond the part 26 as shown in Figure l. A spring pressed plunger 32 engages the back edge of the dog so as to force it outwardly through the slot 31 whereby the shoulder 33 on its top edge may engage beneath a downwardly facing shoulder 34 within the drill collar. A bolt 35 is slidably mounted through the upper end of the part 26 and is provided at its top with a head 35 for engagement by the grapple of a wire line. At its lower end the bolt is provided with a bifurcation or fork 36 straddling the inner or back upright edge of the dog. A lateral hook or foot 37 is provided upon the lower end of each arm of the bifurcation or fork, and a horizontal pin 38 extends across the two feet or hooks 37 and works in a slot 39 provided in the dog and inclined to the vertical, so that by lifting the bolt, its fork will lift the pin 38 through the slot and thereby swing the dog inwardly and withdraw the shoulder 33 from beneath the shoulder 34. The engagement of the dog with the shoulder 34 prevents upward movement of the device or tool of the present invention independently of the drill string. Also, by lowering the drill string, this same engagement will cause the present device or tool to move downwardly with the string.

. In the practice of the present invention by use of the present tool or device, the drill string E and the drill bit F being in the well C, as shown in Figure 1, with the drill bit at the bottom thereof and the well and the drill string full of drilling fluid, the drill string is lifted slightly, until the drill bit has been retracted a suitable distance above the bottom end wall of the well as shown in Figure 1 of the drawings.

The device of the present invention is then dropped or lowered through the drill string and floats downwardly through the drilling fluid until .an external annular shoulder 40 on the barrel A engages an internal shoulder 41 within the bore of the drill bit, and the dog 29 snaps beneath the shoulder 34- within the interior of the drill collar. The barrel A will then project a suitable distance below the drill bit with its lower end short of the bottom end wall of the well, as best shown in Figure l. The reason for retracting the drill bit is to provide room enough below the drill bit and above the bottom end wall of the well to prevent contact of the barrel A with the bottom end wall of the well when lowering the device into position for use thus preventing premature firing of the explosive charge. After the device has reached the position as shown in Figure 1 of the drawings, the drill string is lowered to bring the lower end of the barrel A into con-tact with the bottom end Wall of the Well, with sufficient force to embed the lower edge of the member 9 and the packing ring in the formation, as best shown in Figure 2 of the drawings. The part 9, acting in the manner of a caisson bell excludes drilling fluid from an area of the bottom end wall of the well thereby sealing 01? said area. With the barrel A thus held against downward movement, upon further lowering the drill string, member B will move downwardly within barrel A and against the resistance of the spring 8 thereby bringing the firing pin 22 into contact with the percussion cap or detonator 16, thus effecting explosion thereof. The flame of the explosion will pass downwardly through the passage provided between the meeting edges of the breech blocks 19 and through the opening 21 in the top of the hell or chamber 9 and fire the charge 11 contained therein. The effect of the explosion of the charge 11 is to burn, blast or form the cavity H in the formation as shown in Figures 2 and 3. The shape and dimensions of the cavity H may be controlled by regulating the shape and dimensions of the recess 12 in the charge; the kind and amount of high explosive in said charge, and the distance between the base of the recess 12 in the charge and the surface of the bottom end wall of the bore of the well.

It will, of course, be understood that as the result of the explosion of the charge 11, the interior of the hell or chamber will be empty and the lower end of the firing pin 22 may readily pass downwardly through the chamher and through the opening in the nut or bushing 15. During the downward movement of the member B, the valve 3 will be turned to an open position by the gear or pinion 3 on the outer end thereof traveling downwardly in mesh with a rack 43 rising from the nut 15. The firing pin 22 will then enter the cavity and by reason of the perforations 25, fluid in the cavity will pass into the bore of the firing pin or nozzle and thence upwardly into the bottom of the trap chamber 1 under the pressure diflerential existing between the formation and the trap chamber.

When the combined firing pin and nozzle enters the cavity C, a packing 44 carried by and surrounding the nozzle will seal the same therein as shown in Figure 3, whereby formation fluid under its natural pressure is prevented from escaping upwardly through the top of the cavity and drilling fluid is prevented from leaking into the cavity.

It will here be explained that a very small quantity of drilling fluid may be trapped Within the open bottom of the bell member 9 and below the hood 23. However, the action of the explosion of the charge 11 will dissipate such drilling fluid and therefore no drilling fluid as such will be within the bottom of the hell 9 and therefore there 6 is 'no possibiliy of drilling fluid entering the top of the cavity C.

The firing pin or nozzle 22 is permitted to remain in the cavity for a sufficient length of time to ensure that a desired amount of formation fluid will flow into the trap chamber under the differential between the pressure in the formation and the atmospheric pressure in the chamher. The valve 3 is then closed to trap fluid within the chamber. To close the valve '3, the drill string is slowly raised, thus removing the weight thereof from the latch 2? and permitting the spring 8 to expand, thereby holding down the member A in position in contact with the formation and at the same time moving the member B upwardly within the member A. By virtue of the intermeshing of the pinion 3 carried by the valve 3 and the rack 43 carried by the member A, the relative longitudinal movement between the members A and B will rotate the gear 3 and close the valve. Subsequently, by operation of the wire line, the latch 29 may be withdrawn from engage ment with the drill collar and the tool containing the trapped sample may be elevated to the surface. The Wire line overshot 26 may then be removed and the contents of the chamber 1 drawn off by a suitable con nection engaged with the threaded socket 45, the valve 46 being opened for this purpose.

What I claim is:

l. A retrievable device for lowering through a drill string during drilling operations for obtaining samples or specimens of fluid from the formation below the bottom of an oil well, comprising a pair of slidably connected members, one member carrying a shaped charge and a detonator, the other member having a firing pin in cooperative relation with the detonator and having a longitudinal bore open at opposite ends, said firing pin being mounted on said other member for projection below the bottom of the device for receiving fluid from the formation.

2. A retriievable device for lowering through a drill string during drilling operations for obtaining samples or specimens of fluid from theformation below the bottom of an oil well, comprising apair of members slidable upon one another, one member being provided with an explosive charge chamber opening through the bottom thereof, a detonator seat in cooperative relation with the explosive charge chamber, the other member being provided with a firing pin in cooperative relation with the detonator seat and having a longitudinal bore open at opposite ends, a trap chamber carried by said other member and communicating with the inner open end of the bore, said other member capable of movement on said first member to project its firing pin through the detonator seat, through the explosive chamber and through and beyond the open end thereof, whereby the firing pin may constitute a conduit for leading formation fluid into the trap chamber.

3. A retrievable device for lowering through a drill string during drilling operations for obtainingsamples or specimens of fluid from the formation below the bottom of an oil Well, comprising a lower barrel member, a plunger member telescoping with the barrel member, a caisson bell carried by the barrel member and constituting an explosive charge chamber, a firing pin carried by the plunger and provided with a longitudinal bore open at opposite ends, a detonator seat in cooperative relation with the explosive charge member and with the outer end of the firing pin, and a trap chamber carried by the plunger member and communicating with the bore of the firing pin.

4. A retrievable device for lowering through a drill .string during drilling operations for obtaining samples or specimens of fluid from the formation below'the bottom of an oil well, comprising a lower member having its bottom end provided with means for engagement with the bottom of an oil well and sealing oil drilling fluid from an area of the bottom end wall of the well, an upper member slidable on the lower member, means carried by the lowermember for forming an opening through the sealed oif area of-the bottom end wall of the well and a cavity in the underlying formation, and nozzle means carried by the upper member for actuating said opening forming means and projectable beyond the lower end of the lower member for movement into the cavity.

5. A retrievable device for lowering through a drill string during drilling operations for obtaining samples or specimens of fluid from the formationrbelow the bottom of an oil well, comprising a lower barrel member provided at its bottom end with a caisson bell having a shaped charge member, a detonator seat provided in the barrel in cooperative relation with the shaped charge chamber, a pair of opposite slidable breech blocks between the detonator seat and the shaped charge chamber, the meeting edges of the breech blocks having cooperating grooves forming a passage communicating from the detonator seat to the shaped charge chamber, and a plunger slidable within the barrel and provided with a trap chamber, a firing pin carried by the plunger and having a longitudinal bore open at its opposite ends and in communication with the trap chamber, the said plunger being movable upon the barrel to project the lower end of the firing pin into and through the detonator seat and in between the breech blocks'to separate the same and downwardly through and beyond the open end of the barrel.

6. A device of the class described comprising an upright lower member having means for supporting it upon and within a drill string, an upper member slidable vertically on and projecting above the lower member and provided with a chamber, and an open ended tube depending from the upper memberand in communication with the bottom of the chamber, the projecting portion of the upper member having an overshot latch mechanism for connection with a drill string whereby said upper member may be lowered by lowering the drill string to project the tube below the lower member, and spring means bearing in opposite directions against said members for elevating the upper member on the lower member when the upper member is disconnected from the drill string.

7. The combination with a drill string, of an open ended barrel member within the bottom portion of the drill string and having a supporting connection there with, a plunger telescoped through the open top of the barrel and extending upwardly therefrom, said plunger being provided with an internal chamber and an open ended tube depending therefrom and communicating with the chamber, the upper part of the plunger above the barrel being connected with the drill string whereby the plunger may be lowered through the barrel by downward movement of the drill string, the plunger having an extent of movement such that the tube thereof may be lowered through and beyond the open bottom of the barrel.

The combination with a drill string, of an open ended barrel member within the bottom portion of the drill string and having a supporting connection therewith, a plunger telescoped through the open top of the barrel and extending upwardly therefrom, said plunger being provided with an internal chamber and an open ended tube depending therefrom and communicating with the chamber, the upper part of the plunger above the barrel being connected with the drill string whereby the plunger may be lowered through the barrel by downward movement of the drill string, the plunger having an extent of movement such that the tube part thereof may be lowered through and beyond the open bottom of the barrel, and spring means between the barrel and plunger for elevating the plunger when the plunger is disconnected from the drill string. I p

- 9. The combination with a drill string, of an open ended barrel member within the bottom portion of the drill string and having a supporting connection therewith, a plunger telescoped through the open top of the barrel and extending upwardly therefrom, said plunger being provided with an internal chamber, an open ended tube depending therefrom and in communication with the chamber, the upper part of the plunger above the barrel being connected with the drill string, whereby the plunger may be lowered through the barrel by downward movement of the drill string, a valve between the tube and the chamber, there being a valve operating engagement between the valve and the barrel near the lower limit of the plunger such as will open the valve during downward movement of the plunger and close the valve during upward movement thereof, and spring means to elevate the plunger from its lower limit and thereby close thevalve.

10. The combination with a drill string, of an open ended barrel member within thebottom portion of the drill string and having a supporting connection therewith,

a plunger telescoped through the open top of the barrel 7 and extending upwardly therefrom, said plunger being provided with an internal chamber, an open ended tube depending from the plunger and communicating with the chamber, the upper part of the plunger above the barrel being connected with the drill string whereby the'plunger may be lowered by downward movement of the drill string, a valve controlling communication between the tube and the chamber, there being a valve operating engagement between the valve and the barrel near the lower limit of movementof the plunger such as will open the valve during downward movement of the plunger and close the valve during upward movement thereof, such engagement being provided by a pinion on the valve, and a rack on the barrel in the path of downward movement of the pinion near the lower limit thereof, and spring means to elevate the plunger from its lower limit and travel the pinion along the rack and thereby close the valve.

11. A device for obtaining samples or specimens of formation fluid comprising in combination, a drill string, a member having a bore therethrough, said member being telescopically disposed within the drill string, means for suspending said member from the drill string with at least the lower end of the member projecting below the drill string for engaging the bottom end wall of the well, a shaped charge within said member adjacent the open lower end thereof, a detonator within said member above the shaped charge, formation fluid extracting means slidably disposed within said member and normally disposed above the detonator, latch means on said extracting means engaged with said drill string whereby the extracting means is moved with the drill string, said detonator being disposed in the path of movement of said extractor means whereby the shaped charge is detonated upon downward movement of the extractor means and forms a pocket in the bottom end wall of a well-immediately in advance of the downwardly moving extractor means, and means on said extractor for sealing 01f said pocket.

References Cited in the file of this patent Ramsey Jan. 15, 1952 was ,4,

Claims

1. A RETRIEVABLE DEVICE FOR LOWERING THROUGH A DRILL STRING DURING DRILLING OPERATIONS FOR OBTAINING SAMPLES OR SPECIMENS OF FLUID FROM THE FORMATION BELOW THE BOTTOM OF AN OIL WELL, COMPRISING A PAIR OF SLIDABLY CONNECTED MEMBERS, ONE MEMBER CARRYING A SHAPED CHARGE AND A DETONATOR, THE OTHER MEMBER HAVING A FIRING PIN IN COOPERATIVE RELATION WITH THE DETONATOR AND HAVING A LONGITUDINAL BORE OPEN AT OPPOSITE ENDS, SAID FIRING PIN BEING MOUNTED ON SAID OTHER MEMBER FOR PROJECTION BELOW THE