US1872498A - Blow-out preventer - Google Patents

Description

g- 16, 1932- c. A. RASMUSSEN ET AL 1,372,498

BLOW-OUT PREVENTER Filed May 25, 1929 5 Sheets-Sheet. 1

(lies/Pr A. Rasmussen,

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Aug. 16, 1932.

c. A. R'ASMUSSEN ET AL BLOW-OUT PREVENTER Filed May 25, 1929 5 Sheets-Sheet 2 fNVf/VTORJ C/zesfer A. Res/maul),

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Arron YE)! Aug. 16, 1932. c. A. RASMUSSEN ETAL 1,872,498.

BLOW-OUT PREVENTER 5 Sheets-Sheet 5 Filed May 25. 1929 f/vvz/vro/as: (hes/er ,4. Rasmussen Ml/Mm A. 7; 1; 6r 4 A TTOR/YEX Patented Aug. 16, 1932 UNITED STATES PATENT OFFICE CHESTER A BASMUSSEN, F LONG BEACH, AND WILLIAM A. TROUT, OF LOS ANGELES, CALIFORNIA BLOW-OUT IREVENTER Application filed May 25, 1929. Serial No. 365,812.

The utility of blowout preventers is wellknown in the art, these devices being utilized either for removing a string of drill pipe, with its associated tool joints, from the well without releasing the pressure therein, or for packing off the upper end of the drill pipe to prevent a premature escape of gas, such as is ordinarily known as a blowout. Such blowouts are usually disastrous, both to the workmen who happen to be present and to the eqiiipment being utilized for drilling the we 1.

The blowout preventer of our invention relates to the second type, and is utilized for packing off the upper end of a well until mud may be forced downward into the well in sufficient quantities to prevent any disastrous flow of gas when the blowout preventer is released and the drill pipe removed.-

It is a primary object of this invention-t0 provide a blowout preventer of novel con-- struction which will decrease the danger of blowouts to a minimum, and which is semiautomatic in operation.

A further object of this invention is to provide main and auxiliary packing means for packing off the upper end of a string of drill pipe.

A further object of this invention is to provide a blowout preventer in which the packing members may be easily and quickly replaced, thus decreasing the danger period during the changing of these packing members.

The novel quick-lock means for accomplishing this purpose also forms an important part ofthisinvention. and has been found to be very effective and positive in action.

A further object of this invention is to provide a pressure-operated packing element held in pack ng relationship with the (15511 pipe, orother member, by the pressure which it packs ofi.

It is a further object of the invention to provide an auxiliary pressure means capable of eifecting a satisfactory packing action until such a time as the pressure in the well builds up sufliciently to maintain the packing element in contact with the 'drill pipe, or other member.

Further objects and advantages of the present invention lie in the specific structure of the elements to be shown and described, and

will be apparent to those skilled in the art from the following disclosure:

Referring to the drawings,

Fig. 1 is a vertical sectional view of the preferred form of blowout preventer.

Fig. 2 is a top view taken as indicated by the arrow 2 of Fig. 1.

Fig. 3 is a fragmentary View taken as indicated by the line 3-3 of Fig. 1.

Fig. 4 is a sectional View taken on the line H of Fig. 1.

Fig. 5 is an enlarged sectional view of the upper portion of Fig. 1.

Fig. 6 is a perspective view illustrating the method of assembly of certain elements indicated in Fig. 1.

Fig. 7 is a cross-sectional view taken on the line 7-7 of Fig. 5.

Fig. 8 is a View partially in cross-section and taken'on the line 88 of Fig. 1.

Fig. 9 is a cross-sectional view taken on the line 9-9 of Fig. 1.

Fig. 10 is a view of an alternative form of our invention which may be utilized for packing oflf drill pipes, or other members, of large size.

Fig. 11 is a top view of Fig. 10.

Fig. 12 is an alternative form of the invention disclosed in Fig. 10.

Fig. 13 is another alternative form of the invention in which the packing relationship is maintained throughout a rotation of the drill pipe or other member being packed off.

Figs. 14 and 15 are sectional views taken on the correspondingly numbered lines of Fig. 13.

Referring particularly to Fig. 1, we have illustrated the upper end of a casin 10 as being threaded into the lower end 0 a seat member 11 of our invention. This casing 10 extends downward in a well and communicates .with the hole being drilled by a bit rotated by a drill pipe such as indicated by dotted lines 120i Fig. 1. This drill pipe may be formed in sections joined together by a tool joint such as indicated by dotted lines 13 of this figure. When the drill has penetrated a gas-bearing strata, it is very desirable that the upper end of the drill pipe be packed off to prevent a premature escape of this gas with consequent damage to equipment, as well as the attendant danger to workmen. This is accomplished by the blowout preventer of our invention.

Referring particularly to Figs. 1 and 8, the seat member 11 provides a tapered seat 15 which is adapted to be engaged by a retainer 16 having a correspondin taper, this retainer having packing rings 1 which engage the seat 15.

Secured to the upper end of the retainer 16 by studs 18 and nuts 19 threaded thereon is a cap 20, this cap co-operating with the retainer 16 in defining a packing-retaining structure 21. This structure provides upper and lower channels 22 and 23 and is adapted to retain a packing element 24 in a cavity 25 thereof, this packing element having tongues extending into the channels 22 and 23. I

Formed in the packing element 24 is an annular cavity 27 having a lantern structure 28 disposed therein and adapted to retain upper and lower protrusions 29 and 30 of the pack ing element in spaced relationship. The details of this lantern structure may best be understood by reference to Figs. 1, 8, and 9 wherein this structure is illustrated as comprising a pair of semi-circular, channelshaped elements 31 having legs 32 and 33 extending outward from a base 34 bent to conform to the contour of the inner wall of the cavity 25. Openings 35 are formed through this base at intervals, permitting communication between the cavity 25 and the walls of the packing element 24. The ends of the elements 31 are provided with bosses 36 which are bolted together, as by bolts 37, before the packing element 24 is clamped in the packing-retaining structure 21.

Any pressure which is built up in the annular cavity 27 will thus act to force the packing element 24 inward and into engagement with a tool joint, or other member to be packed oif. This pressure is transmitted through openings 39 formed in the retainer .16 and communicating between the annular cavity 27 and a chamber 40 formed around this retainer. The chamber 40 is supplied with fluid under pressure either from the well or from auxiliary means connected to a pipe 41 communicating with this chamber. The pressure built up in the well is transmitted vto this chamber through a pipe means 42 communicating therewith and with that portion of the seat member 11 which is below the packing element 24. I

This pipe means 42 has threaded therein a nozzle 43 having a restricted orifice 44. Thus,

before the pressure in the well builds up, the packing element 24 may be actuated by pressure received from the pipe 41 and developed by some auxiliary pumping means. The orifice 44 permits an escape of a small amount of fluid from the chamber 40, this escaping fluid passing through the pipe means 42. When, however, the bit strikes a gas-bearing strata, the pressure in the pipe means 42 will gradually build up until such a time as this pressure becomes greater than the pressure in the pipe 41. At this time a valve in the pipe 41 may be shut off, and the pressure developed in the well will automatically retain the packing element 24 in sealing engagement with the member to be packed off, in this case the drill pipe 12 or its associated tool joints 13. Before the packing element 24 can engage this member in sealing relationship, it is necessary that the pressure in the annular cavity 27 be greater than the pressure to which the inner surface of the packing element is subjected. It thus becomes necessary to prevent any flow between this member and the packing element prior to the time that the gas pressure of the well maintains a packing relationship. If such a flow were set up, the pressure in the well would not be sufficient to move the packing element 24 into engagement with the member to be packed off. The auxiliary pressure-supply means prevents any such flow from taking place, and once the pressure in the well becomes high enough, the seal will be automatically maintained without the use of the auxiliary pressure-supply means.

It is extremely desirable that the packingretaining structure 21 be easily and quickly removable from the seat member 11, and also that this structure be firmly held in place therein. These functions are performed by a clamping structure in the form of a bonnet 50 in cooperation with the cap 20. The bonnet 50 is threaded to the upper end of the seat member 11 as indicated by the numeral 51. A quick-lock means between the clamping structure and the cap 20 is provided by interengaging means thereon, this means comprising lugs 52 extending inward at spaced intervals from the walls of an opening 53 of the bonnet 50. The upper edge portions of the lugs 52 are tapered upwardly and inwardly to provide cam surfaces 52, and arms 54 of'the cap 20 have their lower edge portions tapered downwardly and inwardly to provide cam surfaces 54. The opening 53 is of sufficient diameter to pass the cap 20 when arms 54 extending outward therefrom are spaced between the lugs 52 of the bonnet 50. When the ca 20 is first introduced into the opening 53 o the clamping bonnet 50, each of the cam surfaces 54 will be positioned on the corresponding cam surfaces 52 of the clamping bonnet 50, thus centralizing the cap 20. A slight rotation of the bonnet 50, such as may be effected by the use of handles 55, will move the lugs 52 into disaligned position relative to the spaces between the arms 54, thus locking the packingretaining structure in place. A further rotation of the bonnet 50 moves this bonnet into contact with the upper end of the arms 54, thus forcing the packing-retaining structure 21 firmly into the seat member 11.

During this turning of the bonnet 50, the cap 20 is prevented from rotating by means of extensions 57 extending upward from the seat member 11 and. fitting between the arms 54 of the cap 20, as best shown in Figs. 1, 6,

' and 8.

A stop member 60, shown in full lines in Fig. 3 and in dotted lines in Fig. 1, is secured in the seat member 11 and extends outward into the path of travel of a lug 61 extending downward from the bonnet 50. Engagement between the stop member and lug determines the highest position of the bonnet, at which time the entire packing-re taining structure may be lifted vertically from the seat member 11 and repaired or replaced, the reinsertion being accomplished as previously described.

Extending upward from the cap is a neck which acts as a packing-retaining member for an auxiliary packing structure 65a positioned above the main packing structure comprising the packing element 24 with its associated parts. The details of this auxiliary packing structure are best illustrated in Figs. 1, 5, and 7.

Referring particularly to Fig. 5, the neck 65 provides a counterbored portion forming a cavity 66, there being a shoulder 67 between this counterbored portion and a central opening 68 of the neck through which the drill pipe extends. Adapted to extend into the central opening 68 is a lower sleeve 69 having an annular ledge 70 engaging the shoulder 67 and having a central opening 71 which is only very slightly larger than the diameter of the member to be packed off, in this case the drill pipe 12.

Positioned in the counterbored cavity 66 above the lower sleeve 69 is a packing element 78 preferably formed of rubber, or other compressible material, and an upper sleeve member 74 provides a shoulder 75 engaging the upper surface of this packing element and being adapted to compress this packing element against the lower sleeve 69. Relatively long screws 76 extend loosely through the lower sleeve 69 and packing element 73 and are threadedly received in the shoulder 75 of the upper sleeve member 74.

The packing element 73 cooperates with the lower and upper sleeve members 69 and 74 in defining a packing member 80 wh ch is clamped in position by means of a clamping hood 81 which is threadedly received by the upper end of the neck 65, as indicated-by the numeral 83. This clamping action takes place through a pair of locking members 85 which, when in advanced position, extend into a cavity 86 defined between the upper end of the neck 65 and an annular ledge 88 extending inward from the clamping hood 81 and providing an opening 89 which is substantially of the same diameter as the diameter of the counterbored cavity 66. These locking members 85 are arcuate in form, and extend substantially half way around the upper sleeve the walls of the opening 89, so that the packing member 80 may be vertically withdrawn from the packing-retaining member defined by the neck 65. 4

This upward withdrawal of the packing member 80 may be accomplished by any suitable lifting means, but preferably by the use of bails 94 which extend downward in channels 95 formed longitudinally in the upper sleeve member 74. The lower ends of these bails are bent outward to extend below the locking members 85, as best illustrated in Fig. 5, these lower ends fitting in radial channels 96 communicating with the longitudinal channels 95 and formed in the shoulder 75. The upper ends of these bails are bent outward, as indicated in Fig. 5, so as to permit manual engagement therewith.

It should be understood that when the clamping hood 81 is rotated in a manner to decrease the annular space 86, the annular led e 88 comes into clamping relationship wit the upper faces of the locking members 85, and transmits a clamping action therethrough to the packing member 80 in a manner to compress the packing element 73 against the member to be packed ofi.

When it is desirable to renew the packing member or to remove this member, theclamping hood 81 is unscrewed into a position shown in Fig. 5, and a lifting force is exerted on the bails 94. This first raises the locking members 85 into their dotted line position 92, at which time the bails are clamped in the channels 95 by these locking members. A further upward movement of the bails 94 lifts the entire packing member 80 from the neck 65. The advantage of such a construction will be obvious to those skilled in the art. Ordinarily, the clamping hood 81 is rather a heavy member, and it is sometimes difiicult to start the threads thereof in proper relationship with the threads on the neck 65.

With the construction illustrated in Fig. 5, it is never necessary to remove the clamping hood 81 to renew the packing member 80. Even a more important advantage of this construction lies in the fact that should the pressure in the well substantially build up below the packing member 80, this member will not be blown out, even if the clamping hood 81 is unscrewed, asindicated in Fig. '5. The only danger which might arise with such a system would occur only during that short interval of time when the packing member is being lifted and replaced. As soon as the locking members 85 drop into advanced position, no danger of blowout is present.

In Fig. 10, we have illustrated an alternative form of our invention such as may be used when sealing ofi relatively large pipes or members. In this form of our invention, the packingretaining structure 21 extends upward from the retainer 16, this form differing from that shown in Fig. 1, for instance, in that the retainer does not hold the packing element 24 inside the seat member 11, but, instead, positions this packing member above the seat member.

A lantern structure 100, similar to that shown and described in the preferred embodiment of our invention is provided in this alternative form, and the packing element 24 is retained in place by a cap 101 which may be merely a large plate, as shown in Fig. 10, or may be a cap similar to that shown in Fig. 1, thus providing an auxiliary packing means if the use of suchwan auxiliary means is desired. The pipe means for supplying pressure from the well to the place around the packing element 24 is indicated in Fig. 10 by the numeral 102, and provides a valve 103 therein for controlling the flow therethrough. A pipe 104 communicates with the pipe means 102 and with an auxiliary pressure-supply source, this pipe having a valve 105 therein. It should be apparent that such apipe structure may be utilized for performing the same functions as those previously outlined. This is especially true if an orifice is positioned in a coupling 106.

With such a construction, if the valve 103 is open, pressure supplied through the pipe 104 will actuate the packing element 24 and a small amount of the fluid passing through the pipe 104 will pass through the orifice in the coupling 106. When, however, the pressure in the well builds up sufliciently, a reverse flow through this orifice takes place, and the pressure behind the packing element 24 is automatically maintained. At this time the valve 105 may be shut off.

Fig. 12 illustrates a form of the invention somewhat similar to that shown in Fig. 10, but slightly modified, inasmuch as the pressure in the well is built up in a chamber 110 corresponding to the chamber 40 of Fig. 1, and is transmitted through a passage 111 formed through the retainer 16 to the space around the packing element.

Still another form of our invention is shown in Fig. 13 wherein the retainer 16 pro vides a bore 120 communicating with a counterbore 121, there being a shoulder 122 therebetween. The bore 120 is adapted to receive a resilient packing element 125 which is compressed in place by a ring 126 in the counterbore 121, the maximum compression of the packing element 125 taking place when this ring engages the shoulder 122. Positioned above the ring 126 are packing elements 127 and 128 separated by a lantern structure 129 floating in the counterbore 121.

A ring 130 compressed the packing elements 127 and 128, this ring being engaged by a cap 131 threaded to the upper end of the retainer 16. The lantern 129 provides a chamber 135 which communicates with the periphery of the element being packed ofi through openings 136. Oil under pressure is forced through a pipe 137 communicating with the chamber 135, this oil passing through the openings 136 and being utilized for lubricating the sealing surfaces, the type of packer designed in Fig. 13 being primarily utilized for packing the drill pipe during a rotation thereof without undue wear on the packing elements.

In order to further decrease the wear on these elements. we provide an interstitial ring 140 positioned in a counterbore 141 communicating with a bore 142, this bore 142 being slightly larger in diameter than the periphery of the member being packed off so as to provide an annular space 143 therebetween. The interstitial ring 140 is slightly smaller in inner diameter than the opening of the bore 142, this ring having openings 144 therein which allow communication between the annular space 143 and the interior of a pipe 150. This pipe is supplied with a suitable cleaning fluid under pressure, this cleaning fluid passing through the openings 144 and downward between the inner wall of the interstitial ring 140 and the periphery of the drill pipe or other member being packed off, this cleaning fluid being subsequently discharged through the annular space 143 into the seat member 11.

W e have found that such a system prevents the entrance of any mud into contact with the packing elements, and thus prevents undue wear on these elements. This washing action which takes place when the cleaning fluid passes downward around the periphery of the drill pipe is a very important part of this invention.

Any further uses and advantages of the apparatus disclosed in this application will be apparent to those skilled in the art, and we are not, therefore, limited to those shown and described herein.

We claim as our invention:

1. In a blowout preventer, the combination of: a seat member; a packing-retaining structure engaging said seat member; a clamping structure engaging said packingretainin structure; interengaging means on said pac ing-retaining structure and on said seat member for preventing any relative rotation thereof; projections on said packingretaining structure; and tongues on said clamping structure adapted to engage said projections for locking said packing-retaining structure relative to said clamping structure when a relative rotation between said structures takes place.

2. In a blowout preventer, the combination of: a. packing member; a supporting structure for said packing member, said structure providing an annular space therein; a pair of curved locking elements movable from collapsed position in which said packing member may be inserted in said supporting structure into extended position in which said locking elements extend into said annular space; and lifting means extending along the periphery of said supporting structure and operatively engaging said locking elements. 1 1

, 3. In a blowout preventer, the combination of: a packing member; a supporting structure for said packing member, said structure providing an annular space therein; a pair of curved locking elements movable from collapsed position in which said packing member may be inserted in said supporting structure into extended position 1n which said locking elements extend into said annular space; and a shoulder on said packing member which is engaged by said locking elements when in extended position.

4:. In a blowout preventer, the comblnation of: walls formlng an annular space; a member extending inside said walls; a pair of locking members pivoted to said member and extending partially therearound, said locking members being movable from collapsed position to permit movement of said member into an extended position, in which extended position said locking members extend into said space to prevent removal of said member; and means for moving said members from extended to collapsed position.

5. In a blowout preventer, the combination of: walls forming an annular space; a member extending inside said walls; a pair of locking members pivoted to said member and extending partially therearound, said locking members being movable from collapsed position to permit movement of said member into an extended position, in which extended position said locking members extend into said space to prevent removal of said member; and means for lifting said member, said means engaging said locking members to move same into collapsed position before said member is materially moved.

6. In a blowout preventer, the combination: walls forming an annular space; a member extending inside said walls; a pair of locking members pivoted to said member and extending partially therearound, said locking members being movable from collapsed position to permit movement of said member into an extended position, in which extended position said locking members extend into said space to prevent removal of said member; and a pair of bails extending along the periphery of said member and under said locking members to move said. locking members into collapsed position and raise said member.

7. In a blowout preventer, the combination of a packing-retaining member having a cavity therein; a packing member in said cavity; a clamping hood; an annular ledge on said clamping hood and having an opening of sufficient size to pass said packing member, said clamping hood being movable relative to said packing-retaining member in a manner to decrease the space between said ledge and said packing-retaining member; and a locking member extending partially around said packing member and pivoted relative thereto in a manner to move from a position adjacent said packing member to allow insertion and movement of said packing member to an advanced position in which said locking member extends into said space.

8. In a blowout preventer, the combination of: a body structure adapted to be secured to the upper end of a well casing, said body structure having an opening through which atubing may pass, the upper part of said opening being of smaller cross-sectional area than the lower part, and being just large enough to pass; a mechanically-operated packing means in said smaller part of said opening adapted to be caused by mechanical means to engage said tubing, said mechanically-operated packing means being removable; and fluid-operated packing means in the large part of said opening for forming a seal around said tubing to permit the removal of said mechanical packing means.

9. In a blowout preventer, the combination of; a body structure adapted to be secured to the upper end of a Well casing, said body structure having an opening through which a tubing may pass, the upper part of said open: ing being of smaller cross-sectional area than the lower part, and being just large enough to pass; a mechanically-operated packing means in said smaller part of said opening adapted to be caused by mechanical means to engage said tubing, said mechanically-operated packing means being removable; and fluid-operated packing means in the large part of said opening for forming a seal around said tubing to permit the removal of said mechanical packing means, said fluid-operated packing means having an annular pliable wall adapted to engage said tubing to form a fluid seal, therearound.

10. In a blowout preventer, the combination of: a body structure adapted to be secured to the upper part of a well casing, and having an opening throughwhich a tubing may extend; a packer supported in the upper end of said opening, said packer being removable; mechanical means for compressing said packer to cause same to engage and form a seal around said tubing; an annular pliable packer in the lower part of said opening, there being means forming a fluid chamber around said annular pliable packer; and means for supplying a fluid under pressure to said chamber to constrict said annular pliable packer into fluid-tight engagement with said tubing.

11. In a blowout preventer, thecombination of: a body structure adapted to be secured to the upper part of a wellcasing, and having an opening through which a tubing may extend; a packer supported in the upper end of said opening, said packer being removable; mechanical means for compressing said packer to cause same to engage and form a seal around said tubing, an annular pliable packer in the lower part of said opening, there being means forming a fluid chamber around said annular pliable packer; and means for supplying a fluid under pressure to said chamber to constrict said annular pliable packer into fluidtight engagement with said tubing, said annular pliable packer having sufiicient flexibility to engage said tubing.

12. In a blowout preventer, the combination of: a body structure adapted to be secured to the upper part of a well casing and having an opening through which a tubing may extend; a packing retainer secured to the upper end of said opening, apacker within said retainer, mechanical means for compressing said packer to cause the same to engage and form a seal around said tubing; a second packer retainer secured to said first retainer whereby the same may be withdrawn as a unitary assemblage; an annular pliable packer provided by said second retainer and situated in the lower part of said opening, there being means for forming a fluid chamber around said annular pliable packer; and means for supplying fluid under pressure to said chamber to urge said annular pliable packer into fluid tight engagement with said tubing, said annular pliable packer having sufiicient flexibility to engage said tubing.

13. In a blowout preventer, the combination of a body structure adapted to be secured to the upper part of a well casing and having an opening through which a tubing may extend; a packer supported in the upper end of said opening, said packer being removable; mechanical means for compressing said packer to cause the same to engage and form a seal around said tubing; an annular pliable pack er in the lower part of said opening, there be-

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