US2812819A - Blow-out preventer - Google Patents

Description

Nov. 12, 1957 E. J. ALBAREs 2,812,819

BLOW-OUT PREVENTER Filed Dec. 3. 1954 FIG. 2

3| IN VEN TOR.

-E. J. ALBARES ATTORNEYS 2,812,819 Patented Nov. 12, 1957 2,812,819 BLOW-OUT PREVENTER Edwin J. Albares, Thibodaux, La., assignor to Phillips Petroleum Company, a corporation of Delaware Application December 3, 1954, Serial No. 473,011 4 Claims. (Cl. 166-92) This invention relates to drill hole blow-out preventers for use in geophysical prospecting drill holes. In one aspect it relates to an apparatus which permits venting of gas while retaining solid matter blown from geophysical drill holes. In another aspect it relates to such an apparatus which possesses safety features for the protection of the operator.

In some areas of Louisiana it has been found that gas deposits occur within 30 to 40 feet of the earths surface and such shallow deposits of gas frequently blow-out sand and shale from geophysical drill holes following shooting of the holes. If precautionary measures are not taken gas blowing from such drill holes frequently blow-out large quantities of sand and shale. In case the geophysical prospecting is being carried out on agricultural land, the matter blown-out from the drill hole may have to be removed so as not to interfere with agriculture. In one instance a geophysical drill hole in a sugar cane field, after being shot in the usual manner, blew out sand and shale to the extent of 22 truck loads.

An object of my invention is to provide an apparatus for preventing the blow-out of solid material from drill holes after shooting.

Another object of my invention is to provide an apparatus for use in preventing the blow-out of sand and shale from geophysical drill holes following shooting.

Still another object of my invention is to provide a relatively inexpensive and easy to use apparatus for preventing blow-out of solid material from geophysical drill holes following shooting.

Still other objects and advantages of my invention will be realized upon reading the following description, which taken with the attached drawing, forms a part of this disclosure.

In the drawing:

Figure 1 represents, in diagrammatic form, one embodiment of apparatus of my invention.

Figure 2 is an elevational view, partly in section, of another embodiment of my apparatus.

Figure 3 illustrates another embodiment of a portion of my apparatus.

Figure 4 is a sectional view of another portion of my apparatus.

Figure 5 is an elevational view in section, of still another embodiment of a portion of my apparatus.

Referring now to the drawing and specifically to Figure 1 reference numeral 17 identifies the surface of the ground into which a bore hole 11 is drilled. The drilling operation for producing this bore hole is carried out by use of drilling equipment commonly used by geophysical prospecting parties. The type of this drilling apparatus can be any suitable type desired to be used by a drilling crew.

In some instances the drill hole is cased with a tubing as the hole is being drilled. Under other conditions a hole is cased after the drilling operation is complete. However, in areas containing surface deposits of loose material, such as sand, it preferable to case the hole as it is being drilled. In some cases it is desirable to drill the hole with a drill bit attached to the bottom end of' a drill tubing, the drill being adapted to drill a hole of larger diameter than that of the drill tubing. In this case the hole is usually cased with another tubing of diameter about the same as the drfll bit and as the drill hole advances. In any event, after the drilling is completed an explosive charge is lowered into the hole and is detonated. In some areas, as in Louisiana, as mentioned, gas occurs in pockets at distances no greater than the depth ordinarily reached in such drill holes. When a drill hole taps such shallow gas in sandy areas, large quantities of sand are sometimes blown from the hole following shooting. In order to prevent the blowing out of large quantities of sand and shale from a gas-containing deposit identified by reference numeral 18, I attach a pipe section 13, as by a collar 14, to the top of tubing 12. The upper end of the pipe section 13 is provided with a cap 15 prior to attaching to the well tubing. This pipe section 13 is provided with one or more openings 16. When using such an apparatus as illustrated in Figure l the cap 15 is threaded or welded, as illustrated in Figure 5, or is hinged as illustrated in Figure 3, as desired, to the top end of the pipe section 13. After the well is shot the operator approaches the well with this piece of equipment and threads it by means of collar 14 to the top end of the well tubing. It is believed that the space above the openings 16 and below the cap 15 (Fig. 1) acts as a trap or as a solid material separator. Gas containing solid material flows upwardly through the well tubing 12, the solid material continues to move upward beyond the openings 16 While the gas vents from the openings 16 to the atmosphere. Under some conditions it is preferable to employ a deflector such as deflector 33 of Figure 2, or deflector 51 of Figure 4 as a safety means for the protection of the operator. Such a deflector is attached previously, as by welding, to the pipe section 13 so that the operator installing the blow-out preventer will be protected against solid material blown through openings 16.

Solid material which is blown to the upper end of the pipe section 13 drops downward in the pipe and tends to retard the upward flow of gas and solid material. When the volume of the pipe section 13 above openings 16 is relatively large the solid material from that section falls down the tubing and exerts a marked damping effect to the upward flow of gas and in many instances seals off the hole from further flow of gas.

In Figure 2 is shown an embodiment of my invention involving an additional safety device and also a large space between openings for outflow of gas and the top end of the blow-out apparatus. In this figure a pipe section 31 contains openings 32 for outlet of gas. The bottom end of this tube is provided with threads for attaching to a drill hole tubing such as tubing 12 of Figure 1. The deflector 33 is attached to the pipe, as by welding, at such a position that solid material leaving the pipe with the gas will impinge against the underside of the deflector and be thrown downward toward the ground in place of outward in the direction of an operator. To the upper end of pipe section 31 is attached a valve 35 by means of a nipple, and collar 34. When using such a valve, the valve, being opened as by a hand wheel 36, and pipe section 31 are attached to the top of the drill hole tubing. This apparatus is installed on the drill tubing prior to shooting of the hole. After installing this apparatus on the tubing, the shooting charge is lowered into the hole through the valve and with the wires protruding from the upper portion of the valve. With the valve fully open the charge is detonated. After detonation, if the drill hole blows solid material the valve 35 is closed. When valve 35 is closed gas emerges from openings 32 under the deflector 33, and while the valve is still closed another pipe section 40 with its upper end closed by a cap 41 is installed as by a collar 39 to the valve. By providing the valve 35 and having it closed, additional safety is provided for the operator whose'task it is to install capped pipe 40. When this pipe 40 has been installed, the valve 35 is then opened with the result that a relatively large cavity is provided above openings 32 for separation of solid material from the high pressure gas. By providing such a large volume, large quantities of solid material can accumulate therein and the solid material can then fall downward and when the volume of this solid material is sufliciently great it may even seal off the drill hole against further flow of gas.

Under some conditions the drill hole may not be completely sealed against further flow of gas by the weight of a solid material but its weight is sufficiently great as to markedly restrict the flow of gas. The apparatus of Figure 2 and of Figure 1 is allowed to remain attached to the upper end of tubing 12 until such time that the bore hole ceases to vent appreciable quantities of gas. When gas flow ceases the blowout preventing apparatus is removed from the bore hole tubing and taken to another location for subsequent use.

While I have shown in Figures 1 and 2 the upper end of the pipe sections 13 and 40 as being closed by threaded caps and 41, respectively, the use of threaded caps is not necessary since other suitable types of closure means can be used. One other type of closure means is illustrated in Figure 3 and this involves use of a plate 53 attached by hinged hasps. A hinge element 54 comprises an eye 61 over which a hasp 62 is positioned prior to welding eye 61 to pipe section 52. Another eye 56 is attached to the opposite side of pipe 52 in such a manner as to accommodate a hasp 55 attached to the plate 53. A bolt 57 is provided for inserting through eye 56 after hasp 55 is in place in order to hold the plate 53 tightly against the upper end of pipe 52. This embodiment of pipe closure is used with the embodiment of apparatus illustrated in Figure 1, and it is also used with the embodiment of apparatus illustrated in Figure 2, when desired.

In Figure 4 is illustrated a type of deflector 51 which is used for deflecting solid material emerging from openings 16 or 32 for the safety of the operator. The embodiment of deflector of Figure 4 is possibly a little simpler to manufacture than is a deflector 33 of Figure 2 and for this reason alone such a deflector as that of Figure 4 may be preferred.

Still another closure means can be used for closing the upper end of pipes 13 and 40, such a closure means is illustrated in Figure 5. This closure means merely comprises a plate 58 attached by weld 60 to the open end of a pipe 59. This pipe 59 then replaces pipe 40 of Figure 2 or when provided with openings for venting of gas it replaces pipe 13 of Figure 1.

In one instance in which a drill hole tubing or casing was a 3 inch diameter casing and its upper end extended to a level about one foot above the earths surface, a capped pipe similar to pipe 13 was threaded by a collar similar to collar 14 to the upper end of the drill hole tubing. The pipe corresponding to pipe 13 contained a number of drill holes about one inch in diameter. The pipe was about 10 feet in length. The use of such a 10 foot long 3 inch diameter capped pipe with a number of one inch diameter holes for venting of gas was used satisfactorily in preventing the scattering of sand from a geophysical bore hole.

Many times sand blown from such bore holes is blown in slugs, that is, gas will blow relatively freely then all of a sudden a large quantity of sand will accompany the gas. In this case the use of such an apparatus as that illustrated in Figure 2 with the blowout preventing pipe having a large volume above the vent openings is especial- 1y useful. The slug of sand on flowing upward through the tubing in the bore hole at a rapid rate flows beyond the openings 32 while the gas flows out of these openings. When a large quantity of sand reaches this upper pipe its weight then causes it to fall more or less as a mass and frequently such a large mass of sand falling down the tubing plugs or at least restricts the bore hole against further flow of high pressure gas.

As mentioned above the pipe section 31 and valve 35 of the apparatus of Figure 2 can be installed on the bore hole tubing and then the explosive charged fired. If the bore hole does not blow sand the upper capped pipe section 40 is not needed and the bore hole is allowed to blow until the gas pocket has been depleted and when this condition occurs all of this blow out preventing apparatus is removed from the tubing and taken to another location. If, however, during the time which the gas from the pocket is blowing if sand starts it is merely necessary to close valve 35 and install the upper pipe section 40, then open valve 35 and allow the bore hole to blow to depletion.

While certain embodiments of the invention have been described for illustrative purposes the invention obviously is not limited thereto.

I claim:

1. Apparatus for preventing sand and gravel blow-out from a geophysical exploration drill hole lined with a tubing and following discharge of an explosive charge in the lower portion of said drill hole, comprising in combination, a pipe adapted at one end to be attached to the upper portion of said tubing, the other end of said pipe being closed, at least one opening in the wall of said pipe, a funnel shaped deflector disposed around said pipe and attached thereto at its small diameter end, the open end thereof being directed downward, and said deflector surrounding the pipe at the level of said opening in such a manner as to direct downward toward the earth, sand and gravel ejected from the pipe through said opening.

2. The apparatus of claim 1 wherein the closed other end of said pipe is closed by a hinged closure.

3. Apparatus for preventing sand and gravel blow-out from a geophysical exploration drill hole lined with a tubing and following discharge of an explosive charge in the lower portion of said drill hole, comprising in combination, a pipe adapted at one end to be attached to the upper portion of said tubing, at least one opening in the wall of said pipe, a valve communicating with the other end of said pipe, one end of an elongated second pipe communieating with the other end of said valve, the other end of said second pipe being closed, a generally funnel shaped deflector disposed coaxially with said first pipe in such a manner that the deflector surround-s said first pipe at the level of said opening in said pipe and the large diameter open end of said funnel shaped deflector being directed downward in such a manner as to deflect generally downward sand and gravel ejected from said first pipe through said opening.

4. The apparatus of claim 3 wherein the closed other end of said second pipe is closed by a hinged closure.

References Cited in the file of this patent UNITED STATES PATENTS 858,321 Auchu June 25, 1907 911,649 Elsey Feb. 9, 1909 941,452 Henning Nov. 30, 1909 1,595,186 Gray Aug. 10, 1926 1,659,452 Welton Feb. 14, 1928 1,858,241 Giles May 17, 1932 1,868,794 Fuller et a1 July 26, 1932 1,969,513 Kelley Aug. 7, 1934 2,387,770 Rogers et al Oct. 30, 1945

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