US2578996A - Driven well point - Google Patents

Description

De 195] v. A. ENDERSBY 2,578,996

DRIVEN WELL PQINT Filed Jan. 26, 1948 u 5' s P r u. A w

5- ///////////////A|W/////////////.W///// Li r invenfor Victor A Endel sbq His AHorneq Patented Dec. 18, 1951 UNITED STATES PATENT OFFICE DRIVEN WELL POINT Victor A. Enders'by, Lafayette, Calif., assignor to Shell Development Company, San Francisco,

-Calif., acorporation of Delaware Application January 26, 1948, SerialNo. 4,345

3 Claims. .1 r

This invention relates to driven well points adapted to beconneoted to the "bottom end of a pipe or string of tubing and to be driven into the ground by applying-force, e. g., pressure or hammer blows, to the top of the pipe. More particularly, the invention relates to a contractible driven well point wherein the lower driving head or pointed section is reciprocable with respect to the main body and the orifice affording communication between the supporting pipe and the ground formation is covered and protected against deformation or clogging while the point is being driven intothe ground.

The specific embodiments described in this specification were designed for use as injection points, i. e., for use in injecting a fluid into the ground; the invention can, however, also be adapted for withdrawing subterranean fluids,

'e. g., water, gas or oil, from the ground.

There is frequent need for a driven well point which is of rugged construction and which will stand up after repeated driving operations. For example, in injecting various bituminous emulsions into the ground for rendering round impervious to water, it is necessary that the emulsion be injected at a large number of points. As

a specific example, seepage of water through and a under earth or other dams is sometimes controlled by injecting such an emulsion at a large number of pointsspaced both vertically and horizontally to build up an impervious wall beneath the ground. This is effected by driving tubing into the ground and injecting the emulsion at various levels by progressively varying theheight of the discharge point. The tubing mustbe repeatedly driven into the ground at different points, thereby subjecting the point to considerable wear. Unless the parts are of rugged construction stones and other hard objects soon damage the injection orifices, resulting in improper distribution and discharge of the emulsion. To effect proper penetration of the soil, it is desirable that the injection point be firmly packed or sealed against the earth to prevent flow of the high pressure fiuid vertically along the supply pipe. Moreover, when dealing with bituminous emulsions and other materials which are of a viscous nature when dry, or which tend to form sticky deposits, it is important that the well point be readily disassembled for cleaning.

It is an object of this invention to provide a driven well point of rugged construction which protects the communicating orifice while being driven into the ground.

It is a further object to provide an injection point-suitable for injecting bituminous emulsions and the like into the ground which affords :protection for the discharge orifice while the point is being driven into the ground and which can be easily disassembled and cleaned.

Still another object is to provide an injection point of the type described which has a smooth, cylindrical exterior and is readily adapted to form a tight seal against the surrounding earth.

With these and other objects in view, which will become apparent from the following description, reference is made to the accompanying drawing forming a part of this specification, wherein:

Fig. 1 is an elevation view of one embodiment according to the invention in its extended position;

Fig. 2 is a vertical sectional view, taken on line 2-2 of Fig. 1; and

Fig. 3 is a vertical sectional view of a modified form of the device.

Referring to Figs. 1 and 2, the point comprises a heavy cylindrical housing 4, of circular crosssection, having internal threads id for attach ment to a string of pipe and closed at its lower end by a plug or disc 5 which is threaded into the housing. Holes in in the disc permit the insertion of the pins of a tool for tightening or removing the disc 5.

A tube 6 extends through a circular hole in the disc 5 with a close sliding fit. It has an annular out-turned retaining flange 6a at its upper end in guiding engagement with the inner wall of the housing. The lower end of the tube 6 is externally threaded. Above the threads a plurality of in jection orifices 6b are provided. In the embodiment shown these holes are four in number spaced vertically and in different circumferential orientations so that two diametrically opposite holes discharge fluid at one level and the alternate holes discharge at a different level. Any desired number of orifices may be provided. A heavy metal driving head 1 is threaded to the end of the tube 5 and secured by a lock washer 8. Pin holes for receiving pins of a suitable tool when assembling or disassembling are provided at 1a and 8a. While the lock nut 8 may in certain cases be omitted, it was found in practice that some type of locking device was necessary to prevent gradual loosening of the driving head 1 during use, with the resultant injury to the threads at the bottom of the tube 6 and/or loss of the driving head 'i. It will be noted that the nut 8 and the upper portion of the head 1 are cylindrically circular, so that their outer surfaces conform to the outer surface of the housing 4; this insures a close fit against the earth, both above and below the orifices 61). As shown in the drawing, the cylindrical surfaces of the housing and head extend vertically through distances in excess of the diameter thereof. The lower portion of the driving head 1 is conical to form a solid, tapered point.

To use the injection point, the housing 4 is threaded to the lower end of a pipe and driven into the ground. The tube 4 will be urged upwardly into the housing until the lock nut 8 is up against the disc 5 and the bottom of the housing, thereby causing the orifices 6b to move inside of the housing and be protected against injury. The point then presents a smooth exterior surface from the top of the housing to the bottom of the driving head I. When the desired injection level has been reached, the supporting pipe and housing 4 are raised a few inches; the head 1' and tube 6 are held by friction against the earth causing the point to open to the position shown in Figs. 1 and 2. Fluid is then pumped down the tubing under suitable pressure being discharged through the orifices 6b. The fluid will issue with a considerable velocity, due to the small orifices provided, although I may, in certain cases, use large orifices and rely on the fluid pressure to cause penetration into the formation.

To inject fluid at different levels the point may be driven further and the operation repeated. I prefer, however, to drive the point-initially to the lowest depth, and inject at progressively high levels by retracting the tubing as required.

The point is readily cleaned because the tube 6 is open at both ends. It is necessary only to remove the housing 4 from the tubing and to unscrew the head I while holding the-lock nut 8 stationary. For occasional cleaning out of the housing 4 the disc 5 may be further removed.

In the modified form shown in Fig. 3 like reference numbers designate like parts. In this embodiment the bottom of the housing 4 and disc 5 and the top of the lock nut 8 are conical,

in the conical recess in the housing 4 and disc 5; r

when the housing is raised to extend the movable parts, the orifices 6b are exposed and fluid may be injected at a downward angle. Some advantages of the conical construction are that the nut 8 is less likely to carry along particles of rock or earth when it is raised, and that the head and nut 8 are given some lateral support by the conical nesting.

I claim as my invention:

1. A driven well point comprising a cylindrical housing adapted to be connected to the end of a pipe, a removable closure at the lower end of the housing, a tube open atboth ends extending slidably through said closure and having a retaining flange above said closure in guiding engagement with the interior wall of said housing, a driving head having a tapered point threadedly secured about the lower end of said tube and closing off said lower end, a lock washer threaded to said tube above the driving head, said lock washer and the portion of the driving head above the tapered point thereof having cylindrical surfaces co-extensive with the exterior cylindrical surface of the housing, said lock washer and said cylindrical housing having complementary surfaces for sealing the tube from the space outside said cylindrical surfaces when said complementary surfaces are brought together and for transmitting downward thrust from said cylindrical housing through said lock washer to said driving head, and an orifice in said tube above the lock nut located to be exposed beneath said closure when the tube is extended downwardly and to be covered when the tube is retracted upwardly.

2. The driven well point according to claim 1 wherein the tube has a plurality of restricted orifices at different levels and in different circumferential orientations whereby fluid may be ejected as high velocity jets laterally in different directions against the earth between the parts of the earth sealed off by said co-extensive cylin- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 4,267 Duck et al. Feb. 21, 1871 73,688 Arnold Jan. 28, 1868 76,985 Brown Apr. 21, 1868 1,580,325 Perry Apr. 13,1926

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