US2194255A - Blowout preventer - Google Patents

Description

March 19, 1940. ALLEN 2,194,255

BLOWOUT PREVENTER Original Filed Feb. 4, 1936 INVENTOR, ERBERT ALLEN.

BY mm ATTORNEYS Patented Mar. 19, 194i) 1 BLOWOUT PREVENTER Herbert Allen, Houston, Tex., assignor to Cameron Iron Works, a corporation of Texas Continuation of application Serial No. 62,246, February 4, 1936. This application November 23, 1938, Serial No. 242,123

19 Claims.

The invention relates to blowout preventers of the type employed in controlling oil wells, and. particularly to the construction of the ram which effects the closing operation. I

This application is a continuation of my earlier application, Serial No, 62,246 filed February 4, 1936.

Blowout preventers of the type herein disclosed are applied to the well-head in order to completely close the well passage against the escape of fluid when there is no pipe in the well or to close about a pipe and form a seal when the pipe extends through the blowout preventer.

It will be understood that pressure of several thousand pounds per square inch is present in the wells and it is pressure of this magnitude that must be sealed oiT.

In many instances where the drill pipe is in the well the blowout preventer must clamp about the drill pipe and maintain a seal while the drill pipe is being rotated to circulate the mud through the well in order to remove the gas pressures encountered. Under these circumstances the blowout preventer must maintain a seal about the rotating pipe in order to be effective.

It is one of the objects of the invention to provide a blowout preventer ram construction which will seal about the rotating pipe and maintain the seal during a considerable period of rotation.

Another object of the invention is to provide a ram construction wherein the packing material is disposed in aslot in the face of the ram so that it is subjected to compression and will automatically adjust itself to compensate for wear during the rotation of the pipe which is being sealed.

Another object of the invention is to provide a ram in which a body of resilient material is completely confined so that it may carry the load to transmit pressure to form a seal while compensating for wear.

Another object is to employ a resilient means which is so confined that a greater unit area pressure may be applied than is present in the well.

Another object of the invention is to provide a blowout preventer or valve ram construction wherein the packing is protected and reenforced by plates which serve to displace the packing so that a seal will be automatically maintained.

Another object of the invention is to provide a ram construction wherein a plurality of packings are assembled and held in position by the assembled parts of the ram.

Still another object of the invention is to provide a compound ram wherein the piston for effecting movement of the ram is made up as a part of the ram construction.

Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompany drawing wherein:

Fig. 1 is a vertical, sectional view taken through a blowout preventer to which the invention has been applied, one of the rams being shown in side elevation and the other ram in vertical section.

Fig. 2 is a perspective view of one of the ram members with the piston portion thereof removed and a portion of the body of the ram cut away to illustrate the arrangement of the packmg.

Fig. 3 is a side elevation of a ram member which has no pipe receiving portion and which is used in the device when no pipe is present in the well.

Fig. 4 is a side elevation of parts of the ram packing showing their relative position with respect to each other.

Fig. 5 shows a sectional view of the rear sealing packing provided with a reenforcing band.

The blowout preventer housing is indicated at 2 and is arranged for attachment to a flange or cap 3 which may be the upper end of the well casing head, surface casing, or pipe, which extends down into the well.

The housing 2 has the vertical passage 4 therethrough which is the passage which is to be closed by the device. The flange 5 is carried by the upper end of the housing 2 in order to receive other pieces of equipment which may be positioned on the well above the preventer.

Extendin laterally from the passage 4 are the cylinders 6 and l in which the rains 8 are disposed for sliding movement in order that they may move toward and away from each other in closing and opening the passage 4. The particular rams shown in the Fig. 1 form of the invention are rams each of which have a semicircular opening it) in the front thereof and adjacent the center so that the two rams will cooperate together in forming a seal about the pipe which will be received in the two openings Ill.

The ram members 8 are arranged for sliding movement by virtue of the piston [2 which is formed as a part of the ram. This piston reciprocates in an enlarged portion l3 of the cylinder which is formed on the cylinder 6. The passages l4 and I5 are arranged for connection to a suitable source of fluid under pressure which may be applied through the passage 14 to cause closing of the ram and through the passage I5 to efiect the opening thereof.

A suitable locking screw I6 is carried by the rear end I! of the cylinder 8. This locking screw [6 is rotatably mounted in the end member I? and has an enlargement l8 thereon which may abut against the cap ll to lock the ram in closed position or may be used to manually move the ram closed. Anti-friction bearings 19 may be provided in the cap H. The left-hand end of the screw I5 is threaded at 20 and is received in a threaded area 2| in the piston |2 so that the stem I6 is disposed to travel with the ram and piston during their movement. When the ram is moved inwardly, however, the locking screw I 5 can be rotated outwardly until the enlargement 8 abuts the bearing l9, whereupon the ram will be locked against movement because of the threaded connection with the stem. When no lock is desired, the stem will be in the position shown in Fig. l and can slide to and fro through the cap I! depending upon the application of fluid pressure to the back or the front of the piston. If it is desired to manually move the ram the screw will be rotated and the threads 20 cause the ram to move inwardly when the part I8 engages the cap IT.

The passages l4 and i5 will be connected to a suitable source of supply which may be the well pressure or an artificial source, so that the same pressure can be applied to both rams to close them simultaneously when a blowout is imminent, or when it is desired to form a seal about the pipe in the well.

When the blowout preventer is applied to a well where there is no pipe in use the ram of Fig. 3 may be used which is identical with the ram 8 except that the semicircular portion III is not present so that with this form of ram the front faces of the rams will abut against each other to form the seal. The rams may be either cylindrical or rectangular in. section, cylindrical rams being shown for purposes of illustration.

Particular attention is directed to the construction of the ram which includes a body portion 40 which is provided with an enlarged head 4| This head as best seen in Fig. 2 is cylindrical in form, but has a flattened area 42 on the top and bottom thereof in order to form a seating area for couplings or collars on the pipe when it is desired to suspend the weight of a string of pipe on the blowout preventer rams.

The front face of the head 4| has a transverse slot 43 which extends entirely across the head. This slot merges with a longitudinal groove 44 on each side of the head 4|. The slot 43 and grooves 44 are arranged to receive a packing or sealing member 45 which is best seen in Fig. 4. This packing is of peculiar construction in that it has the substantial body portion 46 with the extending arms 49 formed thereon. This body portion is preferably of rubber or other resilient packing material which will withstand considerable pressure and has an inherent resiliency.

The body 46 of the packing has arranged on the top and bottom, plates 41 and 48. These plates are preferably aflixed to the packing by having openings 49 therein through which the rubber or other material has been vulcanized so that the plates are attached to the packing material but may have some movement relative thereto.

The front edges or faces 50 of the plate are flush with the face 5| of the packing material in the form of rams shown in Figs. 1 and 2 and is to be fitted about the pipe. Both of these faces are formed with the concave area 52 which is semicircular in form to correspond with the semicircular opening H) in the ram head 4|.

The plates 41 and 48 may be beveled at 53 on their rear edges and this beveled face 53 will abut against a beveled shoulder 54 on the packing head 45, and as seen in Fig. 4, the packing head 45 is slightly thicker beyond the rear edges of the' plate so that it completely fills the slot 43. The rear shoulder 55 of the packing body 44 abuts against the base 55 of the slot 43. The side arms or legs 49 extend laterally from the body 46 of the packing and are arranged to be snapped into the grooves 44 on either side of the ram. Each of the grooves is provided with a small dowel opening 58 which is to receive a suitable projection which is molded on the inside face of the arms 49. In this manner the arms are properly positioned in the grooves.

It will be particularly noted in both Figs. 1 and 2 that the faces 50 and 5| of the plates and the rubber respectively project beyond the face 60 of the ram and beyond the face of the concaved portion I, so that as the ram moves to closed position the faces 50 and 5| at the side of the center passage will abut against each other on the opposite rams and in the concaved area ill will abut against the pipe before the faces 50 of the opposite rams come into contact with each other. In other words, the packing materials first contact each other and further movement of the rams toward each other effects a compression of the packing material and the ram may move slightly over the plates 41 and 4B.

When this displacement occurs the packing head 46 is trapped or confined in the slot 43 and cannot escape. The plates 4'! and 48 serve as retainer or reenforcing plates to confine the packing where it projects beyond the face 50 of the ram so that the well pressure can'not cause it to flow. Inasmuch as there is no escape for this displaced material except forward toward the pipe being sealed, it seems obvious that the faces 5| of the opposite packings will be forced more firmly against each other and any desired pressure may be thus established in the confined packing.

This feature is of advantage when a rotating pipe is present because the rotation of the pipe obviously causes a wearing away of the central concave face 62 of the packing head 46. As this face is worn away the pressure on the confined material causes it to be displaced toward the front of the packing head and automatically replaces the material being worn away so that a seal is constantly maintained even though there is no further movement of the rams after they have once abutted against each other. This automatic compensation for wear has been found to be of material advantage and in actual use a pipe has been rotated for a considerable period of time and when the ram was retracted it was found that a substantial amount of the packing had been worn away. In fact when the compression was released it showed that sufficient packing had been worn away so that the face 62' retracted some distance beneath the faces of the plates 41 and 48. This indicated clearly that the packing had been displaced forwardly against the rotating pipe to maintain a seal even though some of the packing had been worn away. In other words the packing is fed forwardly to compensate for wear. There may be some relative movement of the packing and the plates because the plates are being held stationary while the ram is forced forwardly and tends to displace the packing material forwardly between the plates and around the rear of the plates.

The compression of the packing material on the faces 5| and 52, is caused by the compression of material in the walls 49 due to the pressure applied to the ram so that a seal is maintained along the sides of the ram and between the ram and the inside of the cylinder 5. There is normally no pressure in the packing and it is only when the packing is confined by the assembly of the housing, the ram and the confining plates that the pressure can be applied and established in, the packing to maintain the seal at all points and to flow to compensate for wear.

In order that there may be no escape of the pressure longitudinally of the ram, the circular seal in has been provided. This sealing ring is arranged to abut against the rear shoulder 12 of the head 4| after having been slipped over the body 40 of the ram. This ring I0 may have a depressed area I3 therein which is arranged to receive the end I4 of the retainer sleeve I5. This sleeve is of a size to fit closely over the body 40 and as seen in the right-hand side of Fig. 1, tends to retain the packing ring 10. This packing I0 tends to form a seal with the inside of the cylinder 6 at the rear end of the head 4| when fluid pressure is introduced through I5 to open the ram and prevents escape of the pressure forwardly from the chamber I3. In this manner a complete annular seal is maintained aroundthe ram which is continuous with the transverse seal across the face and the lateral seal because of the walls 49 abutting thering 10. a

The sleeve I5 has an enlarged flange 11 therein which serves as a seat for the annular packing I8 and forms part of the piston I2. The packing I8 is held in position by the head I9 of the piston which is in turn held in position by cap screws which are threaded into the end of the ram body 40. The packing I8 is shown as having a metal ring 82 as its foundation. This ring has a plurality of openings 83 therein through which the rubber or flexible material 84 has been molded. This ring serves as a stop member to prevent the undue displacement of the flexible material if the cap I9 is forced too tightly against the ram. This metal ring 82 therefore serves as a spacer so that the cap I9 may be clamped firmly in position without unduly distorting the packing. The packing I8 seals with the cylinder l3 against a flow of pressure past the flange I! so that pressure introduced at either I4 or I5 will tend to move the ram. Attention is directed to the clearance between the end of the shank 40 and the cap I9 so that the pressure applied to the cap is transmitted to the packing I8 and thence to the sleeve I5 and the packing III so as to have the same pressure in all of the packings because the sleeve 15 is movable with the packings.

In some instances there may be sufficient wearing away of the 'front packing to allow the rubber in the legs 49 to move'forwardly so that the annular ring I0 also serves as a reservoir for packing material because it may bulge forwardly into the side grooves in transmitting the applied pressure to the front packing.

Fig. 3 shows the same form of ram as the ram 8 except that the front face 80 thereof is smooth, without the concave portion I0 therein. The packing and plates for the face of this ram will be the same as seen in Fig. 2 except the concave area to fit about the pipe will be eliminated and a flat front face will be provided.

In assembling the ram the packing 46 will be deposited in the slot 43 and the grooves 44. The ring Ill will be slipped in position and the sleeve I5 then passed over the body 40. The packing I8 will then be placed in position against the flange ll of the sleeve I5 and finally the cap I9 will be attached in position by the screws 80. The ram when assembled in this position can be slipped in the cylinder 6 and the end cap I I flxed in position over the stem I6 so that the entire device can be readily assembled.

Fig. 5 shows'a modified form of the packing I0 wherein a reenforcing' member 90 has been positioned. This member extends to the outer periphery of the packing so that if excessive pressure is applied to the packing the resilient material thereof cannot be unduly distorted but will be supported by the member until such time as the ram engages the pipe or is closed and thereafter the end I2 of the ram will support the packing. The rams may be either square, flat or circular and of course the packings III and 18 would be of an appropriate shape in order to form a seal,

Broadly the invention contemplates a blowout preventer ram which will effect a seal about a pipe in a well passage and in which a pipe may be rotated for considerable periods of time Without permitting any leakage. The confining of the packing so that a greater unit pressure may be applied thereto than is present in the Well which causes it to form a seal and compensate for wear, is one of the particular features of advantage and the invention is only to be limited by the scope of the appended claims.

What is claimed is:

A packing for valves comprising a body portion, an extending arm at each edge thereof, a member on the top and on the bottom of said body and partly covering the same, said members being set in said packing, a face on'the rear of each member whereby relative movement of said members and said packing causes distortion of the packing.

2. A packing for valves comprising a body portion, an extending arm at each end thereof, a metal plate on the top and on the bottom of said body and partly covering the same, said plates being set in said packing, a beveled face on the rear of each plate whereby movement of said plates relative to said packing causes distortion of the packing to compensate for wear.

3. A packing assembly for valves comprising a body of resilient material, side legs thereon, the forward. portion of said body being of reduced thickness, a tapered shoulder joining the thin and thick portions of the body.

4. A packing assembly for valves comprising a body of resilient material, side legs thereon, the forward portion of said body being of reduced thickness, a tapered shoulder joining the thin and thick portions of the body, and a metal wear plate disposed on each side of the thinner area.

5. In a device adapted to abut an object to seal an opening against pressure, a packing carried in the device, means on said packing and also in said device disposed to abut the object and confine the packing, and means to force the device toward the object to compress the packing and establish a pressure in the confined packing of a value greater than that existing in the opening to be closed.

6. In a closure device for well heads, a body movable in said device, packing carried in said body to abut an object and form a seal, rigid members carried by said packing within said body to also abut the object and to cooperate with said device and body and the object to completely confine saidpacking, and means to move said body to apply pressure to said packing so as to create in the packing a greater pressure than the pressure being sealed against.

'7. In a closure device for. well heads, a body movable in said device. packing carried by said body to abut an object and form a seal. rigid members carried by said packing within said body to also abut the object and to cooperate with said device and body and the object to completely confine said packing, and means to move said body to apply pressure to said packing so as to create in the packing a greater pressure than the pressure being sealed against, said body being movable relative to said members after they abut the object so as to maintain the applied pressure in event of wear on the packing.

8. In a closure device for well heads, a body movable in said device, packing carried by said body to abut an object and form a seal, rigid members carried by said packing to also abut the object and to cooperate with said device and body and the object to completely confine said packing, means to move said body to apply pressure to said packing so as to create in the packing a greater pressure than the pressure being sealed against, and additional means to lock said body in pressure applying position.

9. A packing for use in blowout preventers, valves and the like where the packing is to be carried within a movable member and confined and subjected to pressure to maintaina seal, comprising a body of deformable packing material, and reenforcing means on said body: of material to confine said material when the load applied by the movable member induces a pressure in excess of the pressure being sealed.

10. A packing for use on blowout preventers, valves and the like where there is a movable ram member including a body of deformable material shaped to fit within a transverse groove in the ram, rigid plate members in said groove and carried by the packing, said plate members being slidable in said grooves to displace said packing between them.

11. In a closure device having a housing with a movable closure member therein, a plurality of resilient packings carried by the closure member to abut each other and to be completely confined by the housing, member, and the object being sealed, and means on the packing to abut the object to confinethe packing thereabout when the member is niovedto apply pressure thereto.

12. A closure device of the character described including a movable closure member, a resilient packing carried thereby, means floating on the packing to confine said packing, means to apply pressure through a portion of said packing to move said member to closed position, and a portion on said packing which will flow under such pressure so as to move around said first means to maintain a seal and to compensate for wear of said packing.

13. A closure device of the character described including a movable closure member, a resilient packing carried thereby, means to confine said packing, means to apply pressure through said packing to move said member to closed position, and a portion on said packing which is deformable under such pressure so as to move to maintain a seal to compensate for wear of said packing, said portion including side legs and an annular area.

14. A blowout preventer including a housing, ram members movable therein, each ram including a body, a resilient packing on the front thereof, a resilient packing intermediate the ends of said ram, a resilient packing at the rear, a sleeve floating on said ram between said intermediate and rear packings, and means to apply pressure for closing said ram to said rear packing so that said sleeve will apply pressure to said intermediate and front packings, and side portions on said front packing to be forced forwardly by said intermediate packing in event of wear on said front packing.

15. A closure device for wells including a housing, a closure member therein, a plurality of resilient packings carried by said member to abut each other, said member and said housing to form a seal, rigid members on said packing and in said closure to confine said packings, and means to apply pressure to said packings so as to maintain a greater pressure within the packings than occurs in the well.

16. A blowout preventer including a housing, ram members movable therein, each ram including a body, a resilient packing on the front thereof, a resilient packing intermediate the ends of said ram, a resilient packing at the rear, a sleeve floating on said ram between said intermediate and rear packing, and means to apply pressure for closing said ram to said rear packing so that said sleeve will apply pressureto said intermediate and front packings,. and side portions on said front packing to be forced forwardly by said intermediate packing in event of wear on said front packing, said intermediate packing having a reenforcing member therein to prevent undue distortion against said side legs.

17. A blowout preventer including a housing, ram members movable therein, each ram including a body, a resilient packing on the front thereof, a resilient packing intermediate the ends of said ram, a resilient packing at the rear, a sleeve floating on said ram between said intermediate and rear packings, and means to apply pressure for closing said ram to said rear packing so that said sleeve will apply pressure to said intermediate and front packings, and side portions on said front packing to be forced forwardly by said intermediate packing in event of wear on said front packing, the rear of said sleeve and said rear packing being larger in diameter, and means to introduce pressure against said enlargement to open said rams.

18. A valve packing comprising a U-sha leg portion and an annular head portion transversely of the tops of the legs, and a wear plate carried by the front and rear faces of said leg portion.

19. In a closure device for well heads, a body movable in said device, packing within said body to abut an object and form a seal, rigid members carried by said packing and within said body to also abut the object and to cooperate with said device and 'body and the object to completely confine said packlng, and means to move and lock said body to apply pressure to said packing so as to create and maintain in the packing a greater pressure than the pressure being sealed against.

HERBERT ALLEN.

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