US2162990A - Drilling valve - Google Patents

Description

Patented June 20, 1939 UNITED; STATES PATENT' OFFICE DRILLING VALVE James S. Abercrombie and Herbert Allen,

. Houston, Tex.

Application February 4, 1936, Serial No. 62,267

3 Claims.

The invention relates to an improvement in drilling valves and particularly that type of valve whichis positioned on a well head during the drilling operation in order to completely close the 5 passage when such .closure is desired.

In the drilling of oil and gas wells where considerable pressure is encountered, and the drilling is carried on by the rotary method where slush and mud is continuously circulated down through 16- the drill stem and upwardly through the well bore,

I it is necessary to maintain the well head in condition so that the well may be completely closed oii regardless of whether a string of pipe is in the hole or not. Blowout preventers have been designed to close about a pipe when it is disposed in the well bore, and the. present .valve' is designed to close this same well bore in event there is no pipe present in the well.

The valve of the type herein disclosed must be 20 capable of completely shutting coir the passage even when it is filled with abrasive drilling fluid and must maintain a seal against enormous pressures.

It is one of the objects of the present invention 5 to devise a. drilling valve which canbe closed to eiIect a complete seal.

Anotherobjeet of the invention is to provide a drilling valve wherein the sealing face is positioned adjacent the center of the ram so that it will not be affected by the cutting action of the abrasive material whenthe valve is being closed or opened.

Another'object of the invention is to providea cireularram having a central outstanding sealing seat which is arranged to abut against a corresponding similarly disposed seat in the valve housing so that such outstanding seat will be cleansed by the flow of fluid at the time of sealing.

Another object is to reduce the velocity of the 40 flow of fluid adjacent the area to be sealed as the valve moves to cl position so as to avoid damage to the sealing faces.

Still another object of the invention is to pro vide acircular ramfor'drllling valves which is arranged to cooperate with a transverse face in.

the valve so that the cutting action of the abrasives will occur on the portions of the ram where .themostmetalis present. 4

Another object of the invention is to provide a drilling valve wherein a choke is provided above and below the valve member as it moves to closed position in orderto'choke down the flow of fluid to avoid cutting of the sealing faces as the ram member moves to closed position.

Another object of the invention is to provide a combination ram and piston for drilling valves which can be operated by fluid pressure.

Still another object of the invention is to "provide a choke adjacent the seat of the ram member so that the wear will occur at a point adjacent the 5 position.

Fig. 3 is a sectional-view taken on the line 33 of Fig. 1 and looking at the valve seat. 2 Y

Fig. 4 is a perspective view of the packing memf- 20 bers which are applied to the ram. g

In Fig. 1 the valve housing is shown at 2 and is provided with a flange 3 whereby the valve is attached to its supporting structure. It may be applied directly to the casing orabove or below 2 any other piece of equipment which may be attached to the well. The connection 4 at the top. is to receive any additional equipment such as the christmas tree assembly. The housing 2 is provided with a vertical passage 5 through which the 3;) fluid is to flow and through which the drilling operations are performed.

During the drilling operation the drill stem or other pipe may extend downwardly through this passage and, of course, this valve cannot be-used 35 .when such a pipe passes through the housing.-

Under these circumstances a blowout preventer which will seal about the pipe is usually'applied to the casinghead and the present valve is used to close off the well completely when there is no pipe 40 in the well. 4

- The passage 5 must be sealed completely in order that the valve be effective and in many instances this passage is full of abrasive fluid such as the slush or drilling mud used in the rotary 45' method of drilling wells. at 7 One of the periods when a valve of this type serves its most useful function 'is when .a' gas pocket or pressure formation has been encountered by the drilling bit and it is necessary to 50' remove the bit and drill stem from the well.

the drill stem is raised from the hole naturally there is an upwa'rdflow to some extent of the drilling fluid with the drill bit and this action relieves the pressure caused by the weight of the as mud on the pressure formation, so that there is a tendency for the well to blow out because of the unbalancing of the pressures on the formation at this period.

v As soon as the drill bit has been raised past the ram of this valve it is desirable to quickly close the ram in order to seal of! the well. In some instances pressures of 1000 to 2000 pounds per square inch are encountered and must be sealed oil? by this type of valve.

In view of the fact that it is an abrasive fluid which must be sealed off it seems apparent that there will be considerable cutting action by the abrasives when under high pressure. Instances are known-wherein the abrasive action of the fluid has cut away the ram or valve member to such an extent that a seal could not be obtained. It is with a view of providing avalve wherein the sealing area will be protected against cutting action and kept free of foreign matter at the time of sealing that the present valve has been devised.

-The housing 2 is provided with an offset area 0 which carries a transverse rib or sealing face I which is in the shape of a cross-bar or partition 8. This partition is shown in section in Fig. 1 and. in

front elevation in Fig. 3. Above and belowthis partition are the chambers 0 and II respectively. These chambers are semi-circular in form as seen in Fig. 3. Where this off-set portion joins the central e 8 it is of a circular configuration to form an annular seat I! as seen in Fig. 3.

' This seat is adapted to receive the end of the ram or valve member ll which is also of circular configuration.

- The circular seat I! is broken at the top and the bottom by the recesses or ports I! and I! which lead into the chambers O and II, respectively. It seems obvious that as the ram It moves into the seat I! thatthese recessu II and II wfll be the 4 only outlet for any material from the passage I, Thus any flow of fluid'through the passage will be greatlyrestric'ted and as the end of the rain it enters the seat I! the flow will be directed in through the opening I! upwardly through the 4g chamber 9 past the face I into the chamber II and out through the recess It. I

In other words, the entire flow is directedthrough the chokes II and II and the greatest Y velocity of the fluid will occur at these points so go that any cutting action due to this flow of fluid will therefore occur on the very top and very bottom of the rain it andjalcsely adjacent the chokes II and It. The fact that the chambers I and it are of greater capacity than the chokes .or

55 causes a'retard'ed flow therethrough and across the sealing face I so that such face will not be cut or- In this manner the ram" cooperates with these recesses II and "to form the choke so that when the end of the ram has entered the seat go It and before a seal is formed when the flew of;

fluid would normally be the greatest it is in fact choked to such an extent that the cutting on the face I will be materially reduced or climb: nated.

as The that. Is and n alsoallow the r.- 11 fluid-fromthechamberslandllastherammember moves into'the seat I! to-"eflect closing ofthe.

valve. The fact, that the seat I is outstanding.

prevents the accumulation thereon of any debris 70 or other foreigmmatter which might interfere withthe-sealing ofthe valve. As the packing face approachesthe seattheiziow'isnot completely cut oil and flowflushes or washes the sealing faces of the seat and the at the 7 time theycome in contact to form'the Thus on the ram II. suitable screws I I.

This ram is formed with; a body portion ll 10 which has a head II. This head has a transverse slot 22 which receives a-packing 23. This particular form of packing is best-seen in Fig. 4 and includes the body portion 25 and the extending arms 26 thereon. These arms extend along the 15 sides of the head II and have pin projections 21' which are received in corresponding recesses in the body 20 of the rar'nmember. This packing 23 will be of resilient material so that it can be snapped into position and as seen in Fig. 1 the contact faces thereof project beyond the face 20 of the end of the ram. The packing 23 carries the upper plate '30 and lower plate Ii which may be attached thereto by having the openings 33 fliled -with the resilient material which makes-up. the g5 packing. These plates'fland u may be beveled at 34 to abut against the thickened portion 3' of the packtng. The rear 38 of this body II abuts. against the end 31' of the recess 22 so that the packing is conflned. on three sides and only the as face 28 thereof is exposed. As the ram moves forwardly the face 2. engages the face I to form a seal. As pressure is applied to the ram the packing material being resilient will be compressed and the additional movement of .the ram will tend to 5 drive the packing body forward between the plates because the resilient material is conflned by the ram and the housing and its only avenue of escape is to flow forwardly. In this manner any additional pressure appliedto the ram will-then tend 4b to increase the sealing action by causing the resil-' ient material to flow forwardly against the face I.

In order to form a seal around thep'eriphery of the ram 20 the annular packing 40 is slipped over the shank ll of the ram to form a sealwith the inside of the ram cylinder 02. A retainer sleeve 43 is next slipped over the shank ll in order to confine the packing II which ispreferably of the lip type. when the ram movesto closed position pressure on the head of the packing causes com- .pression of the areas I. so that they will abut the ring II to form a seal therewith.

The-ram 2| isinfacta combinationramand piston because the rearend of the sleeve 4! has an enlarged flange II which with acap l toretain a packing "firms packing forms a seal with the bore 40 of the housing and it will be noted that this bore ll is larger in diameter than the bore 42 so-that a unit pressure applied to the piston 50 will eifect a greater unit. area pressure The" cap is held in position by A-fluid. pressure inlet n is arranged to j pressuretobeappliedto'thepistonendoith1eram 1111 order to move it to closed position while the passageltallowsthepressuretobeappliedtothe opposite sideof the pistonto openthe ram. q Astem ll-isthreadedat ll through'thepiston u so-that fthe slide with the 11ston. When.'hcwever; lt-is.desired to lock the pistonand v rau in'closed"r'msition ll" will be un- 'acreviedimtiltheshoulderl'lthereonengagesthe end of the cylinder 40. This serves as-a stop for 'outward mevement of the stem and u .fiat or of other configuration as circumstances may require.

Broadly the invention contemplates a drilling valve wherein a choke arrangement is provided to restrict the flow at an area which is spaced away from that portion of the valve where the seal is formed. Because of the circular formation of the ram 20 the greatest amount of metal is present at the top and bottom to provide wearing surfaces and' in view of the fact that the flow between the sealing faces 21 and "is materially restricted, it has been found in practice that these faces are always in proper condition to form an adequate seal and have 'not been cut or destroyed by the abrasive action of thefluid as the ram moves to closed position.

What is claimed is:

1. A valve comprising a housing having a passage therethrough, a hollow cylindrical extension on said housing transversely of said passage, a ram in said extension for movement transversely of the passage,,an outstanding packing on said ram, an ofiset in the wall of said housing opposite said cylindrical extension, a transverse partition in said ofiset, said partition having an outstanding sealing face adapted to be contacted by said ram in sealing engagement, and an annular seat in said offset coaxial with said ram and adapted to receive the end of said ram preliminary to sealing engagement of the ram with said transverse partition, said annular seat having recesses above and below said partition to increasingly throttle the flow of fluid through the passage after the ram enters theannular seat and said packing approaches sealing engagement with the sealing face. I

2. In combination a valve housing having a passage therethrough, a chamber transversely of said body, a ram in said chamber, an ofiset'in the wall of the housing opposite said chamber, a seat in said offset adapted to receive the end of the ram, and a transverse partition in said ofiset, said partition having a sealing face to sealably engage the ram after the ram enters said seat, said oflset having recesses above and below said partition whereby increased throttling of fluid through the passage takes place after the ram has entered the seat and as the ram approaches sealing. engagement with the transverse partition.

3. A valve comprising a housing having a passage the'rethrough, a chamber transversely of said housing, a ram in-said chamber, a valve seat in the wall of said housing opposite said chamber to receive the end of the ram, said seat having recesses adjacent the top and bottom thereof, and a transverse rib within said valve seat for sealing engagement with said ram after the end of the ram enters the seat so that said recesses reduce the rate of flow and cleanse said rib at the time'of sealing.

HERBERT ALLEN. Y JAMES B; ABERCROMBIE.

Images