US2412915A - Pressure core barrel - Google Patents

Description

Dec. 17, 1946.

B. W. SEWELL PRESSURE CORE BARREL Filed June 15, 1942 2 Sheets-Sheet 2 4. 9Z JMNVENTOR.

Patented Dec. 17, 1946 ES PAT 2,412,915 PRESSURE CORE BARREL Benjamin W. Sewell, Tulsa, Okla., assignor to Standard Oil Developm ration of Delaware ent Company; a corpo- Application June 15, 1942, Serial No; 447.047

5. Claims. (Cl. 255- 72) The present invention is directed to a wire linepressure core barrel.

The principal object of the present in ention is the provision in a device of the character described of an improved valve actuating means.. Other objects of the present invention are to simplify construction of a device of the character described and to impart more positive action to the parts thereof.

Further objects and advantages of the present invention will appear from the following detailed description of the accompanying drawings, in which i Fig. 1 is a front elevation, partly in section, of the upper part of one type of pressure core barrel according to thepresent invention in coring position;

Fig. 2 is a similar view of the lower part. of the same core barrel in the same position;

Fig. 3 is a similar viewof the upper part of the same core barrel with parts in position for the recovery therefrom of the trapped constitu ents; and I Fig. 4 is a similar view of the lower part of the same barrel in the same position.

Referring to the drawings in detail, numeral I designates the upper portion of the drill collar of the drill string, and 2 the lower portion. The two are screwed together, and mounted in the joint between them is aring 3 having an internal diameter which, for the purpose of description, will hereinafter be referred to as X. Secured to the lower end. of the bottom section 2 of the drill collar is the drilling head 4 which is provided with rotarycutters 5 and a central passage 6 for receiving the core. Drillingmud passages 1 connect the interior of the drill collar with the seats of the rotary bits.

Fixed in place in the lower section of the drill .collar is the core barrel assembly, consisting essentially of a pressure tube 8 in which the core receiving barrel 9 is slidingly arranged. Attached to the lower end of the pressure tube is a valve body consisting essentially of a sleeve Ill having an external diameter such as to make a sliding fit with X. The upper end of the sleeve is in screw thread engagement with the lower end of the pressure tube. The intermediate position of the sleeve is cut away to form two opposed windows H and two opposed arms l2 having flat inside faces. Set in the cut away portion in such a way as to protrude is a ball valve [3 having a central passage adapted to pass thecore receiving barrel 9. The ball is seated on one side on the inner circumference of the sleeve 10 and on the other side on the upper rim of a liner l5. .Wlien tlie' core barrel is in its core receiving position, the. ball valve has on one side a-vertically arranged groove I! in which is fixed a pawl l8 the finger end of which protrudes upwardly beyondthe out; side diameter of the sleeve Ill. The periphery of the latter is slotted to receive the pawl for the purpose hereafter specified. The ly spring pressed outwardly.

The upper end of the core receiving barrel carries a check valve l9 which is adapted to permit the flow of fluid outwardly from the barrel and prevent flow in the opposite direction. Extending upwardly from this valve is stem 20 which terminates in a spearhead 2 l. The upper end of the pressure tube 8 carries a plug 22 which has an" outside diameter substantially less than X, but. which carries longitudinally disposed ribs 23 which are of only slightly. smallerdiameter than X. The space between the ribs is provided for the passage of the drilling fluid. The lower end, of the plug 22 carries a ring 24 which is adapted to seat on. a gasket 25 carried in the annular surface provided on the upper end of thecheck valve The upper end of the plug 22 isprovided with" an inwardly directed lip 26 which is adapted to receive a lug 21 pivoted in a slot in the stem 20. This lug is so shaped that when the spearhead is in its lowermost position the lug is forced out ward. When the spearhead is pulled outwardly, the lug can move inwardly in the recess in the stem 20. 1

The exterior of pressure tube 8 is provided with circumferentially spaced longitudinal leaf springs. 28 which perform the double function ofbreaki in: means and spacing means. Inuse, the entire assembly is dropped into the drill stem'. The springs 28 are so designed as to provide suflicient friction against the interior of the drill stem'to' impede the downward fall of the assembly su'flicient to prevent it from being injured when it reaches the bottom.

With the parts in the position shown, the core is out and passes upwardly into the core receiving barrel. The barrel is held in suitably spaced relation in the drill collar by spacers 28. When sufiicient core is cut a fishing tool is dropped into the drill stem to engage the head and an upward pull is exerted on the stem 20. This draws the core receiving barrel upward in the pressure tube until the ring 24 is seated on the gasket 25, thereby sealing the interior of the core barrel. It may be observed here that as core material enters the barrel the fluid in the barrel leaves OFFICE'Q- panel is normall passes through the ring 3 the lower edge of thelatter engages the finger of the valve and with continued upward movement of the "assembly causes the pawl to rotate around thehoriz ontal axis. At this end there is a slot 131. in the sleeve l0 and the liner IE to receive the pawl [8. This results in the sealing of the lower end of the core receiving barrel and the assembly is then brought to the surface.

As shown in Fig. 4, thelcollar is provided above thearms H with opposite disposed diaphragm discs 32i These enter into the operations at the surface when the barrel is recovered. Through one of'these discsthere is connected a pressure measuring device 33 of the character illustrated in FigJ2 of U. S. Patent 2,243,398, issued May 27, 1941; It'may be noted that in this case thepressure onthe outside of the disc is created by scre w-' ing iii-screw 31." To the opening covered by the other disc, is attached'a' fitting 34 in which-is arranged a plunger 35for rupturing the disc, and to permit. the fluid contents thereof to'pass outthrougl'i a tube' 36 The'valve I3 is then opened and the upper end of the stem 20 i taken off, and the core receiving barrel is withdrawn from the pressure tube.

'Itwillj be apparent that many changes may be made the spe'cificstructure without departing frolni thescope of the present invention.- The specific embodiment illustrated is a preferred embodiment to which the present inventioniis not necessarily limited.

The nature "and objects of the present invention having been thus described and illustrated, what is claimed as'new and useful and is desired to be secured by Letters Patent is:

1. A pressure, retaining coring assembly for bringing a; core to the surface of the ground at'thelsa'rne pressure the core left the formation,com'prising a string of drill tubing,. a core barrel adapted tofbe'lowered into and raised completely out of the string of drill tubing during normal drilling operations, a bit having a passage in the center thereof attached to, the end of the drill tubing to cut the core, the core when out passing upwardly through the passage in the bit and into the lower end of the core barrel;

means on the core barrel to receive lifting means lowered within the drill tubing to lift the core barrel complet'elyout of thegdrill tubing when coring is completed, a valve for" closing said core barrel when the latter is lifted out of the coring position and co-acting means carried by said valve and said drill tubing for actuating said valve.

2. A pressure retaining coring device for bringing a core to the surface of the ground at the same pressure the core left the formation, comprising a string of drill tubing, a core'catching assembly adapted to belowered into and raised completely out of the string of drill tubing during normal drilling operations comprising a casing and a core barrel slidingly mounted in said casing, a valve carried by said casing adapted to assume an open and a closed position and to passsaidbarrel when in open position, abit having a passage in' the center thereof attached to the end. of. the/drill tubing to cut the core, the core when cut passing upwardly through the passage in the bit and. into the lower end of the core barrel, means on the core barrel to receive lifting means lowered within the drill tubing to lift the core barrel completely'out'of the drill tubing when coring is completed, co-acting elements carried by said. core barrel and said casing for causing the latter to rise after a predeitermined upward movement of the former and co-acting, means carried by said valve and said drill tubing to move said valve to a closed: position during the upward movement of said casing.

3.. A coring device according'to claim 2 in which the means for receiving lifting means'is an upwardly extending stem on said core barrel adapted to receive a wire line and in which said core barrel and said casing are provided with J matingv elements for sealing the upper end of said casing after a predetermined upwardmov'e-e ment of said barrel relative to said casing. f:

I 4. A coring device'according'to claim 2' in which the coring. assembly is adapted to be dropped through the drill tubing during the" drilling operation and is provided on its outer surface with means for frictionally engaging the inner'surface of the drilltubing to retard the rate of fall of said assembly therethrough.

5. A coring assembly according to claim 1 in which the coacting means for actuating the valve comprises an arm' extending laterally from and moveable with the valve normally occupying a laterally extended position when the valve'is open and an abutment carried by the tubing and ar-

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