US1141910A - Casing-coupling. - Google Patents

Description

J. A. MASON.

CASING COUPLING.

APPLICATION FILED APR. 10. 1914.

Patented J une 1, 1915.

Q IF IT!!! L u E I 4 n T m INVENTDR ATTURNEY.

JESSE A. MASON, OF MANININGTON, WEST VIRGINIA.-

i i CASING-COUPLING.

LIdLQlO.

To all whom it may concern Be it known that I, Jesse A. Mason, a citizen of the United States of America, and resident of Mannington, countyof Marion, and State of \Vest Virginia, have invented certain new and useful Improvements in Casing-Couplings, of which the following is a specification.

This invention relates to couplings designed for use in connection with well casing or tubing, and it has for its primary object to provide a coupling for deep-Well casing which will permit of the ready removal or withdrawal of such casing from the well.

Hitherto the couplings universally used have been formed with a well-defined, or pronounced, external annular inwardlydirected bevel or rounded shoulder at each ofits ends. Due to this beveled or rounded shoulder, much trouble is experienced in withdrawing the casing, and many millions of feet of the latter are yearly left in abandoned oil and gas wells because of inability to withdraw it. The cause of the ditliculty will be realized when it is understood that earth caves in and settles close around the casing at occasional points throughout the depth of the well, and that. to withdraw the string of easing, the couplings, which have a diameter greater than that of the casing, must be drawn through the casing-embracing earth, displacing the latter. In elevating the string of casing the beveled or .rounded upper end of the couplings acts to exert upon the embracing earth a wedging pressure which forces said earth outward and upward, the line of force exerted by such coupling upon said earth being at substantially an angle of degrees to the axis of the well. As the string is elevated, the resistance offered by the embracing earth I constantly increases, due to the fact that said earth is constantly becoming more compact with the elevation of the coupling thereagainst; With such resistance, added to the great suspended weight of a long string of casing, it frequently happens that, after an elevation of a few feet, it isutterly impossible to apply sufficient power to ac complish a further elevation. In like manner the lower end of the coupling acts to prevent the casing from being lowered. Thus, the casing becomes stuck fast in the hole and must be abandoned, ofttimes resulting in a great financial loss. Furthermore,

Specification of Letters Iatent.

Application filed April 10, 1914. sea-1&1 No. 831,059.

Patented June I, 1915.

the use of the common form of coupling frequently results in the spreading and consequent breakage of the elevators employed in elevating the casing. This is due to the fact that the lower beveled or rounded end of the coupling engaged by the clamp members of the tool exerts, under the stress imposed by the great weight of the suspended casing, even under the most favorable elevating conditions, a wedging force upon said members which tends to spread the.

latter in a manner well understood by those skilled in the art.

It is the object of the present invention, therefore, to obviate the difliculties above noted, and this is attained by the provision of a coupling of an extremely simple and inexpensive form, the nature of which will hereinafter be fully explained. reference being had to the accompanying drawings, forming a part of this specification, in which- Figure 1 is a sectional view of a well,-

showing in side elevation, a string of casing disposed therein, the casing sections being connected by means of my improved .coupling, and showing the earth from the walls of the well closing the space around the casing; and Fig. 2 is an enlarged sectional view of the coupling applied to two adjacent casing sections.

Referring to said drawings, in which like designating characters distinguish like parts throughout the several views'1 indicates the sections of a noil or gas well casing which have their ends threaded exteriorlv, as ordinarily, and 2 indicates the interiorly threaded sleeve-like body of my improved coupling, the same being of uniform exterior diameter from end to end and presenting clean out circumferential end surfaces 3 which are disposed at right angles to the axis of the body 2.

Casing the sections of which are connected by means of my couplings may be readily withdrawn from the well, the squared ends of the couplings readily cutting their way upward through, and thus clearing the coupling, of obstructions instead of forcing the latter outward. There is no tendency, therefore, to force or wedge the earth in an upward and outward direction until the latter becomes so compact as to resist furtherelevation, as is the case when the above-mentioned common form of coupling is employed. ,In practice, a cutting edge is presented at the circumferential angle 4 which, when the casing is being elevated, cuts directly through, and does not tend to wedgingly compact, earth which lies-in embracing relation to the casing. Furthermore, the plain shoulder presented by the lower end of the coupling affords a positive seat for the clamp members 5 of the elevator employed for elevating the casing. Thus the tendency to wedgingly spread said clamp members apart, encountered in the use of the common form of coupling, as hereinbefore explained, is Wholly obviated. This is an important feature, since, in addition to the breakage of elevators resulting from the spreading of the clamp members when the common form of coupling 'is used, it frequently happens, in lowering easing into a well, that, due to the great weight of sus pended casing, the clamp members are spread apart by the coupling to an extent that the lower body portion of the coupling wedges down between said members where it partially collapses under the excessive gripping force. When the coupling is thus distorted or collapsed it is difiicult, if not wholly impossible, to introduce the next joint, or casing section, within the coupling.

lVhile the change from the common form of coupling to the improved form constituting the present invention might appear slight to those not skilled in the art. such change results in the production of a device which permits of the recovery of casing which, with the preexisting form, has been wholly iriecoverable and which, in the oil and gas fields of the United States, totals annually many millions of feet.

lVhat is claimed is,

The combination with the adjacent exteriorly threaded ends of well-casing sections, of a coupling therefor comprising an interiorly threaded sleeve-like body the exterior diameter of which is uniform throughout and greater than that of said sections, each end of said body presenting a plane circumferential surface disposed at right angles to the axis and constituting a projecting earth cutting shoulder.

In testimony whereof, I aifix my signature in presence of two subscribing witnesses.

JESSE A. MASON.

'Witnesses:

CHAS. V. ToBEN, GEO. A. CooHRANa.

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