US2841422A - Low pressure blowout preventer - Google Patents

Description

July 1, 1958 A. s. BADGER LOW PRESSURE BLOWOUT PREVENTER Filed June 23, 1955 2 Sheets-Sheet 1 INVENTOR.

ALGERNON S. BADGER,

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July 1, 1958 A. s. BADGER LOW PRESSURE BLOWOUT PREVENTER 2 Sheets-Sheet 2 Filed June 23, 1955 FBG. 4A.-

INVENTOR. ALGERNON s. BADGER,

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United States Patent Ofifice 2,841,422 Patented July 1, 195's LOW PRESSURE BLOWOUT PREVENTER Algernon S. Badger, Houston, Tex., assignor, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N. 1., a corporation of Delaware Application June 23, 1955, Serial No. 517,473

6 Claims. (Cl. 286-165) The present invention is directed to an improved low pressure blowout preventer for controlling the pressures encountered during the operation of drilling a well. More specifically, the present invention is directed to a blowout preventer in which the sealing means is a deformable sleeve positioned in and fixed to a housing which is attached to the top of a casing such as surface casing which has previously been cemented in place in the ground. v

The purpose of the present invention is to form a positive seal around a drill pipe extending through the device and therefore close off the annulus between the casing or borehole and the drill pipe. This purpose is suitably accomplished by forming on the inner surface of the deformable sleeve a series of projections or serrations that will overlap and interlock with one another and fill any voids or Openings caused by crimping of the sleeve when the sleeve is forced against the drill pipe which is of a substantial smaller diameter than the deformable sleeve.

In a blowout preventer where a sleeve-type sealing member is used to seal around the drill pipe, the sleeve has to be large enough in its undeformed position to allow a drill bit, for example a 9%" bit, to pass through and when pressure is applied to the outer Wall of the sleeve to seal around the drill pipe, such as a 4 /2" outside diameter pipe. The sleeve, if it has a constant or smooth inside diameter, will crimp or form folds upon coming in contact with the pipe.

These folds or crimping of the rubber sleeve form openings or slits between the sleeve and the pipe and, therefore, do not provide a positive seal around the drill pipe.

The present invention has overcome this disadvantage as will be seen in the description taken in conjunction with the drawings in which:

Fig. 1 is an elevation, partly in section, illustrating the device of the present invention attached to the top of a surface casing during drilling operation;

Fig. 2 is an enlarged sectional view of the device of Fig. 1;

Fig. 3 illustrates the sleeve member of the device in sealing relationship with the drill pipe;

Fig. 4A is a sectional view of the deformable sleeve member of the present invention in the undeformed position;

Figs. 43 and 4C are sectional views showing the shapes assumed by the deformable sleeve when partially and fully expanded about a section of pipe;

, Fig. 4D is an enlarged fragmentary sectional view taken along the line 4d4d of Fig. 4C;

Fig. 5 (Sheet 1) is an enlarged fragmentary sectional view of the device of Figs. 1 and 2;

Fig. 6 is a sectional view taken along the line 66 of Fig. 5;

Fig. 7 is a showing of another embodiment of the sleeve member of Figs. 1 through 5;

Fig. 8 is a top view of Fig. 7;

Fig. 9 is a top view of another embodiment of a sleeve member;

Fig. 10 is a sectional view taken along the line 10-10 of Fig. 9; and

Fig. 11 is a showing of still another embodiment of a deformable sleeve member.

Turning now to the drawings and especially to Figs. 1 through 6, numeral 11 designates a housing which is attached to a surface casing 12 by means such as a flange member 13 and bolts 14.

Concentrically positioned in housing 11 and fixed to the upper and lower ends of the housing 11 by clamping rings 15 and clamp bolts 16 is a deformable sleeve member 20. Enclosed by and extending through housing 11 and casing 12 is a drill pipe 8.

Sleeve member 20 forms at its upper end and its lower end annular shoulders 21 by which the sleeve 20 is secured to the housing 11 by clamping rings 15.

The Wall of the housing 11 and the sleeve 20 form a pressure-tight annulus or chamber 22. Housing 11 is also provided with a threaded inlet 23 to which is attached by a screw fitting 24 a pressure hose or conduit 25.

Conduit 25 is attached to a pressure source such as an air compressor not shown.

When it is desired to seal around the drill pipe 8, such as when excess formation pressures are encountered, pressure is applied to the chamber or annulus 22, therefore squeezing the deformable sleeve 20 around the drill pipe 8 and sealing of the casing annulus below the sleeve member 20 as illustrated in Fig. 3. A possible first position and 'a closed position taken by the deformable sleeve member 20 upon applying pressure to the chamber 22 are illustrated in Figs. 4B and 4C. It may be understood that sleeve 20 may assume any of several positions or shapes upon contacting the pipe 8.

Turning now to Figs. 5 and 6, the sleeve member 20 is reinforced at its clamping ends by reinforcing means 26 such as cord or fabric which may be nylon ribbons and the like embedded in and vulcanized to the rubber. These reinforcing members are embedded in the annular shoulders 21 and also extend a substantial distance into the wall of the sleeve member 20. This allows a stiffening and strengthening effect for clamping of the sleeve to the housing.

Sleeve member 20 is also provided with a plurality of vertically extending reinforcing members shown as short lengths of cable 27 which are also embedded in the wall of the sleeve 20 and equally spaced apart in the wall of the sleeve 20.

The inner surface of the sleeve 20 defines at a point midway between its upper and lower ends a plurality of inwardly projecting annular serrations or saw tooth projections 28. These serrations are shown as triangular in cross section but may be formed in various patterns as desired.

The serrations or projections 28 form part of the inner wall of the sleeve member 29 but are of a more pliable consistency than the rest of the sleeve 20. The serrations 28, being of a softer or more pliable nature than the rest of the sleeve member, have a tendency to be squeezed or mashed out more readily when coming into contact with the pipe and overlapping and interlocking with one another, therefore filling up any cracks or openings formed by folding or crimping the sleeve member 20 when it contacts the pipe as is illustrated more clearly in Figs. 3 to 4C. Figs. 4B and 4C illustrate one of a number of positions that the deformable sleeve 20 may assume when fluid pressure is applied to the chamber 20.

As shown in Fig. 4B, the sleeve 20 has contacted the pipe 8 at three points and has assumed a crosssectional triangular configuration and leaving openings such as a, b, and c between the sleeve 20 andthe. pipe 8.

As more pressure is applied to chamber 22, the Walls forming the openings at, bpand c are folded together until they assume the position asshownjin Fig. 4C. The serrations 28 of the walls upon being closedftogether,

being somewhat triangular in cross-section and having rather sharp' crests, tend: to slip somewhat and overlap and interlock with one another. The serrations 28., being also. of a softer or more pliable composition: than the wall of the sleeve20, are mashed together and against the pipe 8 and, therefore, completely close any opening between the sleeve 20 and the. pipe 8 in the first folded positioni.

The sleeve 2!} may, upon being pressurized, initially.

contact. the pipe 8 at two or maybefour points and, if so, the openings formed, such as shown in Fig. 4B, are closed in the same manner as described.

The embodiment of Figs. 7 and 8 shows a sleeve member 30 provided with twospaced-apart sets of annular internally projecting serrations 31. In this embodia adapted to seal off a well bore comprising, in combination,

a housingwadapted to be connected into a surface casing in said well bore and having a vertical axial opening therethrough, a deformable sleeve member arranged in said housing concentric to said axial opening whereby a fluid-tight annular chamber is formed between the inner Wall of said housing and the outer wall of said sleeve member, said housing beingprovided with a fluid'inlet communicating with said fluid-tight annular chamber,

merit .the wall of the sleeve member 3% is reinforced 7 immediately above and below the serrations 31 by reinforced means 32 such as fabric which may be nylon or the like.

The embodiment of Figs. 9 and 10 shows a deformable sleeve member 4%) provided with equally spaced-apart sets, of vertically extending serrations 41a, 41b, and .410. This embodiment, as in Figs. 7 and 8, is also provided with reinforcingtmeans 42 which are'embedded 'in the wall of the sleeve member 40 immediately above and I below' the serrations. It. will be understood that the Sleevev 46 of Figs. 9 and 10 is formed so that when it is pressurized it folds around a pipe arranged therein such that serrations 41a come together, as do serrations 41b andlc' and seal the slits formed by the sleeve as previously explained.

Fig; ll is similar to the showing of Figs. 9' and 10 but with the vertical serrations equally spaced apart.

Having fully describedand illustrated the present invention, whatI claimis: V a

"1. A device for controlling pressures ina well and said deformable sleeve member having formed .on its inner wall a plurality of inwardly projectingannular serrations, said wall ofsaid deformable sleeve member being internally reinforced adjacent said serrations and at each of its ends, saiddeformable-sleeve member having a non-deformed position whereby said vertical axial opening is unobstructed and a maximum deformed position whereby said axial opening is completely closed.

2. A device in accordance with claim 1 in which the continuous inwardly projecting annular serrations; are

formed. of; a more pliable composition than said :wall of said deformable sleeve member. I v i 3. A device for controlling pressures in a well and adapted to seal off a well bore comprising in combination a tubular housing adapted to be connected into a surface casing in said well bore, a deformable sleeve member having an opening therethrough mounted in said housing.

and forming with said housing a pressure-tight annular chamber, saidthousing being formed t'o'provide a fluid inlet; communicating: with said annular chamber, said sleeve member being provided with a plurality of'internally proiectingserrations on its inner Wall intermediate its upper and lower ends, said serrations being of a greater deformability than said sleeve member whereby 1 when said annular chamber is pressurized said sleeve .is

deformed and the opening: through said sleeve is sealed. 4. A device in accordance with claim 3 in. which said deformable sleeve member is internally reinforced at each end and adjacent said serrations.

51A device in accordance with claim 4 in which the internally projecting serrations are annularly extending.

6; A device; in accordance withdclaim 4 in which the inwardly projecting serrations are spaced apart and vertically extending.

References Cited in the file of this patent- V UNITED" STATES PATENTS 1,930,361 1,942,366 Seamark Jan.'2, 1934 2,258,887 Fortune Oct. 14, 1941 2,306,160

Kilmer Oct. 10,1933

7 Freyssinet Dec. 22, 1-942

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