US2009888A - Automatic casinghead equipment - Google Patents

Description

July 30, 1935. F. w AH4|LD v 21,009,888

AUTOMATIC CASIG HEAD EQUIPMENT v Filed July 28, 1930 A s sheets-sheet 1 July 30, 1935.

F. w. HILD AUTOMATIC CASING HEAD EQUIPMENT Filed July J28, 1950 3 Sheets-Sheet 2 aww 324%@ M/Q'/ F. W. HILD AUTOMATIC CASING HEAD EQUIPMENT July so,l 1935.

s sheets-sheet s Filed July 28, 1950 Patented July 30, 1935 y l UNITED STATES PATENT OFFICE 15 Claims.

My invention relates to the control and prey vention of iiuid blow outs from wells.

It is an object of my present invention to provide equipment which shall automatically function to prevent escape of the well fluid upon the earliest manifestation of unstable iiuid conditions in the well casing.

Another object of my invention is to provide an automatic casing valve which shall close automatically upon withdrawal of the drill from the casing.

Another object of my invention is to provide a blow out prevented in the casing valve for cooperation with the drill string.

Another object is to provide an automatic mud valve which shall automatically close the well outlets upon change of specific gravity of the uid passing through the valve and/or upon change of the iluid level and/or upon change of the rate of the fluid flow.

Another object is to provide for concentrically disposed well casings-terminal collars having vent heads and vent pipes at substantially the same common level.

Certain other features of my present invention are improvements of those disclosed in my co-pending applications Serial No. 382,384, filed July 3l, 1929, now Patent No. 1,938,020 and Serial No. 385,270, led August 12, 1929, now Patent No. 1,906,265.

Other objects and advantages of my invention will be apparent from the following descriptions and the accompanying drawings:

Figure l is a vertical elevation of the apparatus embodying my invention.

Figure 2 is a vertical section of Figure l.

Figure 3 is a vertical section of the automatic mud valve.

Figure 4 is a vertical section taken on the line 5 4 of Figure 3.

Figure 5 is an end view of the mud valve outlet.

Figure 6 is a horizontal part section taken on the line `S--li of Figure 2.

Figure 'l shows in vertical section another view of the automatic casing valve showing the valve gate in intermediate and closed positions.

Figure 8 is a horizontal plan view in part section taken on the line 8 8 of Figure 2.

Figure 9 is a horizontal View in part section of the casing valve.

Figure l0 is a vertical elevation in part section of -the casing valve.

vFigure 1l is a view in part vertical sectionl showing the springs and pistons for closing the gate of the casing Valve.

(Cl. 16B-15) Figure 12 is a diagrammatic View of the moving parts of the casing valve.

Referring to the drawings, the casings l5, I6, l1 and i8 are threaded into and suspended from casing terminal collars I9, 20, 2i and 22 respectively which in turn rest upon foundation 23. The automatic casing valve 25 is secured to the casing terminal collars by flange collar 24. The

main or axial outlet of the casing valve contains the axial blowout preventer 26 through which the kelly or drill stem 21 extends; a split socket wrench 28 is engaged by the rotary machine 29 for tightening or freeing the preventer 26 in the casing valve 25. The automatic mud valve 30 is connected by the pipe 3| to a lateral outlet of the casing valve 25.

Terminal collar i9 is seated in and contained by terminal collar 20; likewise collar 20 is seated in terminal collar 2l which in turn is seated in and contained by terminal collar 22. Packings 3i supplement the tight fits between the termiral collars in providing iluid tight joints between the casings. In order to control fluid which might accumulate between the strings of casings, channels leading to suitable vent heads are formed in the outer terminal collars, none being needed for the innermost collar when it is for the final, or oil string. Thus channels 32 extend to vent heads 33 of terminal collar 20, and into the vent heads are threaded the usual vent pipes 34 which have hand operated valves (not shown). In like manner terminal collar 2| has channels 35, vent heads 3B and vent pipes 31. Outermost terminal collar 22 has channels 38, vent heads 39 and vent pipes 40,

Flange collar 24 is threaded fluid tight into the innermost terminal collar i9 and is also secured by bolts 4l to the outermost casing terminal collar 22, thereby adding the force exerted by the bolts to the force due to the heavy weight of the suspended casings in rmly seating each terminal collar in the adjacent containing collar so as to lock them all together solidly as a unit. The ange collar 24 Ahas the thread 42 for receiving the Christmas Tree pipe assembly for flowing well or a tubing head for pumping. Obviously when the innermost string of casing is the oil string and therefore the final string, the flange collar and the oil string terminal collar can be one piece instead of two.

The casing valve 25 is secured fluid tight to the flange collar 24 in any suitable manner as by tongues and grooves 44 and bolts 43. The casing valve body 45 has a lateral outlet 46 to which the automatic mud valve 30 is connected and another lateral outlet 41 which is kept normally closed by a hand valve (not shown) This outlet 41 is used to admit mud fluid or to draw oil well fluid under certain conditions of drilling or bringing in the well. Into the main or axial outlet of the casing valve body 45 is firmly secured the v'alve bushing 48 the under face of which forms the valve seatA 49 and against which the valve gate 59 automatically swings to close the axial outlet when the valve body does not contain pipe or the drill string. The valve gate 50, circular in form, has a central pin l which is engaged by the trunnion arm52. The central pin 5| may rotate loosely in the trunnion arm so as to permit the valve gate 50 to adjust itself into good closing contact with valve seat 49. For convenience of assembly the trunnion arm 52 is in two parts bolted together and is pivoted in the valve body 45 by the trunnion pins 53 which are held in place by the blind plugs 54. The trunnion arm 52 has crank pinsI 55 against which force may be exerted to swing the trunnion arm upwardly or downwardly and thereby close or open the casing valve 25.`

Upward movement is by one or both of two forces, one force being that of a pair of springs which always act to automatically close the casing valve. The other force is by any suitable pressure such as by the mud pump, or steam, or the water supply system of adequate pressure. Two cylindrical holes 55 bored in the valve body 45 contain the hollow pistons 51. Within each piston is sleeve 58 containing the helical spring 59 which resting on the inner bottom of the piston, acts always to force the sleeve 58 upwardly against crank pin 55. The cylinders 56 at their lower ends communicate with uid channel 60 which in turn communicates with inlet 8|. This inlet is controlled by a suitable triple valve 62 which connects with the mud pump or other iluid pressure supply. The triple valve also controls the discharge opening 63 which permits fluid to drain from the cylinders 56 and from fluid channel 60 into the well casing. A twoway valve, the same as triple valve 52 has been described and illustrated in detail in my copending application Serial No. 384,213 for Automatic blowout preventer, filed August 7, 1929. Rotating the triple valve 62 in one direction admits iiuid under pressure to cylinders 55 and forces the pistons 51 upward against crank pins 55, this force being additional to the force of the springs 59 for closing the valve gate 50. Movement of the triple valve 62 in the opposite direction shuts off the fluid supply and opens discharge opening 63 draining the fluid from the cylinders 56 into the well casing whereupon the pistons 51 will move down to their bottom positions.

The cylinders are closed at the top by blind plugs 54 through one of which the casing valve stem 65 is threaded. The valve stem 65 may be rotated downward against a crank pin 55 to force and hold open valve gate 50. Reverse rotation of the stem backs it against its seat in blind plug 64 thus efectivelypreventing leakage past the threads of stem 65. A second means for holding open the valve gate is provided by the ring 86 which rests upon a ledge 81 in the valve body 45. The inner bore of the ring is less than the diameter of the drill bit 68 but suiciently large to freely pass the tool joints or couplings and the protectors. Just before threading the bit into the drill collar of the drill string, the ring 66 is placed on the drill collar above the bit, and when the bit is lowered through the valve 25, the ring encounters the ledge 61. The valve stem 65 is thenbacked oli permitting the springs 59 to force the valve gate 50 against the ring 66. On coming out the hole the ascending bit 68 intercepts the ring 66 and carries it upward, whereupon the springs 59 automatically close the valve gate 50 against its seat 49. Should there also be upward movement of the Well fluid, this too will act to force the valve gate upward into its seat, and the well fluid pressure will be added to that of the springs in maintaining closure of the casing valve 25.

The valve bushing 48 has external thread 69 for receiving locking nut lll. The upper end of the locking nut forms the outer half of breech lock 1| An upwardly extending lug 12 of the valve body 45 has an adjustable set screw 13 for limiting unscrewing of the locking nut from valve bushing 48. A ring 14 projecting from the locking nut 18 intercepts the set screw 13 for this purpose.

The axial blowout preventer 26 may be assembled on the kelly 21 and lowered therewith into bushing 48 of casing valve 25 and may rest upon ring 66. A tapered plug has a central opening for snug sliding t on thc drill stem, and has outwardly the form of a truncated cone. The plug consists of packing 16 which may be of rubber moulded on to two metal pieces, one the plug top 11 and the other the plug bottom 18. The plug is journaled in the taper bored preventer shell i9 the outer lower part of which is threaded to receive the retaining ring 80 and also the jam ring 8| for locking the retaining ring in position. The retaining ring has an annular projection which limits the downward movement of the plug l5 and upon which the plug may rotate. Upward movement of the plug is restricted by the taper bore of the preventer shell 19. When the plug is moved upward as by lifting the drill stem 21 or by pressure of the well fluid, the rubber packing 16 is forced against the taper bore which causes compression of the rubber inwardly so that it packs more tightly against the drill stem. When extremes of pressure are encountered, the plug top 11 and the plug bottom 18 which are made of metal, are also forced against the taper bore of shell 19. The upper portion 82 of shell `i9 is a hollow cylinder in form and has an outwardly projecting shoulder 83. An-inward ledge 84 on the bushing 48 intercepts shoulder 83, so that il ring 56 be omitted, downward movement of the blowout preventer 26 is nevertheless limited and it cannot fall through into the well. An annular packing ring 85 of rubber or like material is formed on the portion 82 and rests upon the shoulder' 83. Resting upon and in position to press down upon the packing ring 85 is locking member 86 which at its upper outer portion consitutes the inner mate to the breech lock 1| of the locking nut 1D. The upper inner portion of the locking member 85 is hexagonal in form to rcceive the hexagonal socket wrench 29.

The socket wrench 28 is of two parts hinged together so that the wrench may be placed' around the kelly and lowered' into the hexagonal socket of locking member 86. Upon rotating this socket wrench as by the rotary machine 29, the

locking member 86 will first be rotated into locking engagement with breech lock 1l and continued rotation will screw the locking nut 'l downward carrying with it the locking member 86. This will exert downward pressure on the packing ring 85 forcing it tightly against shoulder 83 of shell 19 and against the walls of valve bushing 48 and cylindrical portion 82 of the shell 19 thus effectively preventing the escape of the fluid past the outside of the preventerZS and rmly locking the preventer into the casing valve 25.

The automatic mud valve 30 has the body 81 containing two compartments one for the specie gravity Valve 88 and the other for the flow level valve 89. A cover plate 90 encloses the two compartments except for valve inlet 9| and valve outlet 92. Between the two compartments is opening 99 which is the outlet for the specific gravity valve 88 and the inlet for ow level valve 89. The specific gravity gate 94 is of wood or other material which will oat in ordinary mud fluid but which will sink when the specic gravity of the mud fluid is diminished as by water dilution or gas. The valve gate 94 swings on pln 95, the ends of which are securedin blind holes in `thc body 31 and the cover plate 99.

The flow level Valve gate 9G is outside hung by reason of its lever arm 91 which swings on pin 98, the pin being secured to body 81 outside and above the valve outlet 92. The valve gate 96 has limited movement about pin 99 of the lever arm 91 so that the valve gate may be self-adjusting when against its valve seat at outlet $2. Hung on the same pin- 98 is pilot gate |09 which normally closes outlet 92 when no liquid flows through it. When however liquid begins to flow through the valve and from outlet 92, the pilot gate |99 swings outwardly and actuates a signal such as an electric buzzer to indicate flow and conversely cessation of flow. As the flow level in the valve rises the flow ultimately encounters the valve gate 96 and acts to swing the gate to close the valve. A counter balance arm serves to diminish the required pressure for swinging the valve gate. Both the valve lever arm 91 and the pilot gate |90 are provided with jaws on their adjacent faces at the pin 98; these jaws intercept when the pilot gate swings out to a suilicient angle with respect to the lever arm 91 so that the pilot gate assists the valve gate 96 in effecting closure of the automatic mud valve.

A pipe |92 controlled by hand valve |03 is threaded into the top of. specific gravity valve compartment 88. Likewise a pipe |04 controlled by hand valve |85 is threaded into the top of flow level valve compartment 89. .The two pipes are for several purposes: Thus pipe |92 may serve as an air vent when mud uid rises in specic gravity valve compartment 88; or it may be used to draw uid from the well casing; or it may admit mud fluid or the like to close the specific gravity valve gate 94 and to replenish the mud supply in the casing. Pipe |84 may admit mud fluid to close the flow level valve gate 96 and to open valve gate 94, and also to replenish the mud supply in the well.

When the casing valve 25 has been closed whether by the hydraulic pistons 51, the springs 59 or by the well fluid pressure-it may be required to hold the Valve gate 59 firmly closed and relieve the pistons and the springs of this duty. Such a means is shown in Figure '7; a threaded hole in the center of valve gate 5U receives the threaded end of stem or handle EDG to- Which is secured circular plate |01 which ts into valve bushing 48 and is forced by the handle |06 tightly onto a shoulder |08 of said bushing.

Considering the operation of the apparatus it should be noted that the outlet 92 of the automatic mud valve 30 is at a higher level than the top of taper plug 15, so that the plug rotates inthe mud fluid which serves as its lubrication.

When the mud fluid ceases' to flow from outlet 92, whether because of automatic closure of either of the two valve gates in the mud valve 30, or because of interruptiion or loss of the mud circulation,-the pilot gate |90 will at once indicate the cessation of flow and conversely also the resumption of flow.

When the drill releases high underground pressures, this usually results in diluting the mud uid by gas. The specific gravity valve gate 94 will then sink and automatically close theoutlet, whereupon the well uid will seek escape at the axial outlet of casing valve 25 which contains the blowout preventer 26 and the kelly 21h The rising fluid will carry the preventer plug firmly. into its tapered seat in shell 19. Should the circulating mud be lost as in large cavities or by inltration or should the mud level be otherwise lowered as when withdrawing the drill string, the valve gate 94 will descend to closing position.

Under certain other conditions of well drilling and in certain oil fields, the bit may release high underground pressures which may result in unstable equil'brium of the mud column inthe well without sufcient change of its specific gravity to permit the valve gate 94 to sink. In such event upon rise of the uid ow through outlet 92 of the mud valve 38, the ilow level valve gate 96 will automatically close the mud valve outlet with consequent automatic closure of the axialY outlet of casing valve by the blow out preventer plug 15.

In this embodiment of my invention, the bushing 48 serves as the valve seat and other casing valve purposes. However considering the bushing 48 and the several parts secured and contained by it, it is manifest that the bushing 48 may be secured into any other kind of casinghead. The rapid, simple operation of inserting and locking the prevcnter 26 into bushing 48 of casing valve 25 or other equivalent casinghead, and its equally facile removal therefrom, all from the derrick noonmade possible by my invention-.-eliminates a dangerous hazard to the workers who for other types of preventer devices have been required to do this work at the casinghead under the derrick floor.

Upon withdrawing the kelly, a split packer for round drill 'pipe similar to that illustrated in my aforesaid co-pending application Serial No. 385,- 270 may be inserted in bushing 48 of the casing valve or equivalent casinghead and quickly locked in place by the means provided by my invention.

In the event of unstable fluid conditions as the drill is nally withdrawn, it is manifest from the previous description that both the casing Valve' 25 and the mud valve 30 will close automatically therebyr anticipating and effectively preventing blowout from the well casing.

Fluid pressure within 'the casing valve is exerted upon the flange collar 24 and the innermost terminal collar with resultant increase of pressure and tighter seating of each inner terminal ing the casing's in interlocking support, namely one part for each string of casing, and the minimum number of possible leakage paths are achieved.

Terminal collars which with their vent heads and vent pipes are disposed at a common level instead of being superimposed, make possible the termination of the casings at about the ground level thereby eliminating the cellar, and enables installing the casinghead equipment in the relatively small space between the ground surface and the dcrrick floor,-all of which are important contributions to safety for the men and the entire installation, and to greater facility of operation, inspection and maintenance.

Although I have described several specific embodiments of my invention, it will be obvious to those skilled in the art, that various modifications may be made in the details of construction, the general arrangement, the association of the several co-operating parts and the application of my invention without departing from the spirit thereof or the principles herein set forth.

I claim as my invention:

l. A blowout preventer for automatically preventing thc blowout of a fluid from a casing head, comprising a valve mechanism having a plurality of pivoted valve gates each independently controlling the flow of fluid therethrough, manually operated means for opening and closing one of said gates, and manually controlled means for admitting fluid under pressure into the valve mechanism between gates for opening one gate to permit said uid to pass into the well, and for closing the other gate to prevent fluid from escaping from said head.

2. A valve for controlling fluid flow from a well, and a valve gate normally floating in said fluid, passing through said valve and sinkable therein upon decrease of the specic gravity of said fluid.

3. In apparatus for preventing `blowout of fluids from a well casing head, means forming an outlet from said head, and a valve closure mechanism for the outlet, said closure mechanism being so constructed and arranged that it is actuated to close the outlet by any of the following: a decrease in specific gravity of the fluid; an increase in the pressure thereof; a rise of fluidlevel in the casing.

4. In apparatus for preventing blowout of fluids from a well casing head, means forming an outlet for fluid from said head, and a valve closure for the outlet, so constructed and arranged that it is actuated to close the outlet by a rise of fluid level in the casing.

5. In apparatus for preventing blowout of fluids from a well casing head, means forming an outlet chamber from said head, said chamber being below the level of fluid at normal operation, and a submerged movable closure in the chamber for the outlet and having a definite specific gravity so that its position in the chamber is dependent upon the specific gravity of the fluid.

6. In apparatus for preventing blowout of fluids from a well casing head, means forming an outlet chamber from said head, said chamber being below the level of fluid at normal operation, means forming a closure for the outlet, and submerged in the chamber, and a pivotal support for.

the means, said means having a definite specific gravity so that its submerged angular position on its pivot depends upon the specific gravity of the fluid.

7. In apparatus for preventing blowout of fluids from a well casing head, means forming ari outlet chamber from said head, said chamber being below the level of fluid at normal operation, and a submerged closure in the chamber, said closure being pivoted above a seat in the chamber and extending from the pivot toward the inlet side of the chamber, said closure having a definite specific gravity so that its angular position in the chamber becomes nearer vertical upon a decrease in specific gravity of the fluid, and in position to be acted upon by the fluid pressure to effect complete closure of the outlet.

8. In apparatus for preventing blow-out of fluids from a well casing head, means forming an outlet conduit from said head, said conduit having an opening substantially at normal fluid level, and a movable valve closure for said opening, said closure being in the path of flow of fluid when the fluid level rises above a definite level higher than the lower limit of the opening, whereby said closure is moved by said fluid to close the opening.

9. A blow-out prcventer for a casing head, comprising means forming a fluid outlet from the casing head, a pair of separated valve closures for closing the outlet, means for so supporting said closures that fluid pressure in the casing may maintain said closures in closed position, and means intermediate said closures for conducting fluid under pressure into the head past one closure while causing the other closure to close.

10. A blow-out preventer for a casing head, comprising means forming an upwardly directed fluid outlet from said casing head, a pair of valve closures in said outlet, one of said closures being in the lower end of the outlet, and the other being in the higher end thereof, means for supporting the lower closure so that it may be maintained in closed position by pressure inside the casing, means for supporting the upper 'closure to be in the path of fluid escaping from the outlet when the fluid level exceeds a definite point, and means for admitting fluid under pressure between said closures, to open the lower closure for the entry of said fluid, and to close the upper closure.

11. In apparatus for preventing blowout of fluids from a welt casing head-means forming an outlet from the head, said means providing a pair of valve seats on opposite sides of the end of the outlet, a pair of closures coacting respectively with said seats, and means forming a common pivot above the seats, for both closures.

l2. In apparatus for preventing blowout of fluids from a well casing head, means forming an outlet from the head, saidmeans providing a pair of valve seats on opposite sides of the end of the outlet, a pair of closures coacting respectively with said seats, means forming a common pivot above the seats, for both closures, and means whereby opening movement of the outer closure assists the closing movement of the inner closure.

13. In apparatus for preventing the blowout of fluid from a casing head, having an outlet, a valve mechanism in the outlet for controlling it, said valve mechanism including means for closing the outlet, actuated by a reduction in the specific gravity of said fluid below a desired minimum value, or by an increase in pressure thereof, above a desired maximum value.

14. In apparatus for preventing blow-out of fluids from a well casing head, means forming a fluid outlet from said head, and a valve mechanism for controlling said outlet, said mechanism including a member actuated in response to variations in specific gravity of the fluid and moved to cause the Valve mechanism to close upon a reduction in the specic gravity below a desired minimum value.

15. In apparatus for preventing blow-out of fluids from a well casing head, means forming an outlet from said head, and a Valve closure mechanism for controlling said outlet, said valve closure mechanism including a member normally oating in uid passing through the Valve mechanism and acting in response t0 a reduction in the specic gravity of the uid below a desired value, to cause the outlet to close.

FREDERIC W. HILD.

Images