US3067820A - Well head assembly for petroleum wells - Google Patents

Description

Dec. 11, 1962 w. G. GREEN WELL HEAD ASSEMBLY FOR PETROLEUM WELLS INVENTOR. W. a. GREEN i llll.

E Z4 M 9.

AGENT United States Patent Office 3,067,820 Patented Dec. 11, 1962 3,067,820 WELL HEAD ASSEMBLY FOR PETROLEUM WELLS William G. Green, Tulsa, Okla, assignor, by direct and mesne assignments, to Aquatron Engineering Corp, St. Petersburg, Fla, a corporation of Florida Filed July 23, 1958, Ser. No. 750,359 2 Claims. (Cl. 166-88) This invention relates to the physical construction of an improved oil Well head assembly.

A variety of well head assemblies have heretofore been proposed, illustrative of which is that set forth in Patent No. 2,082,107 granted to James H. Howard on June 1, 1937. Such assemblies have, however, been complex in design, expensive and in many instances difficult to assemble.

It is therefore one general object of this invention to improve well heads.

Another object is to provide an extremely simple and yet exceedingly effective well head which is economical, rugged in construction and durable in performance.

Yet another object of this invention is to provide a unique locking of certain of the well head elements thereby to increase safety and prevent failure due to blowouts or other causes.

Still another object of this invention is to provide in a well head assembly, members which both automatically center and lock in assembly the various concentric members which are conventional to an oil well bore.

A further object is to provide electrical insulation between the oil well tubing and easing, thereby to permit I electrical measurement of a variety of electrical pheno-mena.

Accordingly, in accordance with one feature of the invention, a simple yet rugged tapered steel plug is mounted upon the well surface pipe, the casing pipe is inserted therethrough, and a plurality of steel balls are suitably disposed circumferentially between the outer surface of the pipe and the inner tapered surface of the plug, thereby automatically centering the casing within the surface pipe.

In accordance with another feature of this invention, an additional plug is arranged to cooperatively mate with the tapered steel plug whereby, when the additional plug is screwed into the tapered plug, a downward thrust is applied to the steel balls to move them down along the tapered surface and force them into the pipe wall, thereby locking the pipe, balls and plugs together into one fixed assembly.

In accordance with yet another feature of the invention, the string of tubing within the casing is locked to the casing by a somewhat similar assembly, the tapered plug, however, being made of a suitable insulating substance such as Mi-carta or Formica and having a tapered annular hardened steel ring for cooperative association with the aforementioned steel balls. Thus, the well pipe string is electrically insulated from the surface pipe and well casing.

In accordance with still a further feature of the invention, a cylindrical ring is snugly fitted about the pipe in each of the two assemblies at a point just below the location of the steel balls to prevent any substantial vertical movement of the pipe in the event the partial embedding of the balls themselves in the pipe walls should fail to hold the pipe in position, thereby greatly enhancing the safety of the assemblies.

In accordance with another feature of the invention, the cylindrical ring is so related to the surrounding dimensions that it will, when the tubing is lifted up, raise the balls to a position of easy removal and prevent their dropping into the well bore.

These and other objects and features of the invention will be apparent from the following detailed description,

by way of example, with reference to the drawing in which the single FIGURE depicts the vertical section of a Well head constructed in accordance with the principles underlying the invention.

It will be seen therein that in the earth 4 there is a conventional T 2 which is mounted upon the upper end of an oil well surface pipe 3. Pipe 3 is suitably anchored in concrete (not shown) and T 2 provides a means of access through opening 5 to the space intermediate the surface pipe 3 and the casing 6. Snugly fitted upon casing 6 is a safety ring 7 which may be secured to casing 6 by set screws 8 (as shown) or by other suitable means such as shrink fitting. The purpose of this ring and the function performed by it are hereinafter more particularly set forth below.

Screwed into T 2 is tapered sleel plug 9 which is equipped with mounting threads 10 about its lower outer periphery and with a hardened tapered surface 11 about its lower inner surface, the smallest inside diameter of plug 9 being greater than the outer diameter of ring 7 in order to allow the ring to project up past the lower end of plug 9 as depicted.

In the space intermediate the plug and the casing are a plurality of steel or other suitably hardened balls 12 which, when forced down by the inclined surface 13 of inner plug 14, move longitudinally down along the pipe and tapered surface 11. Since the available space decreases due to the taper, and since the balls and tapered surface are harder than the wall of the pipe, the pipe wall will deform as the balls dig therein, thus locking the various cooperating members 6, 9, 12 and 14 together.

The ring or sleeve 7 is suitably secured to casing 6 at a point slightly below the point the balls will occupy at the end of their travel. It serves to prevent any substantial upward movement of the casing with respect to the remaining members in the event of abnormal conditions such as an unexpected increase in well pressure, etc. The ring thus acts as a back-up safety device in the event forces tending to upwardly displace the casing should exceed those for which the ball locking assembly is designed.

The remainder of the elements depicted below the reference line 15 are conventional. Thus, for example, suitable compression seals 16 are provided to prevent the escape of well products from the space intermediate the.

casing and surface pipe.

Now turning to that part of the drawing above the reference line, it will be noted that depicted there is a somewhat similar locking assembly which serves to lock the inner tubing 17 to the casing 6. Certain differences exist, however, between the upper and lower locking assemblies. Thus, in the upper assembly, for example, the one-piece cross 18 replaces the T 2. Another difference lies in the material and construction of the tapered plug 19 which corresponds to plug 9 to the lower joint.

Plug 19 is made of some suitable insulating material such as Formica or Micarta. It is suitably threaded, and is milled to receive a tapered steel ring 20 which is hardened in order to provide the desired bearing surface.

In all other respects, the upper assembly corresponds to its lower counterpart.

Angles 21 and 22 may be welded to cross 18 and coupling 23 in order to provide a convenient means of making independent electrical connections to the casing and inner tubing wherever desired and particularly for the purposes shown in my copending application Serial No. 655,406 filed Apr. 26, 1957, entitled Paraffin Removing Device as well as for other uses.

The method of assembly of both joints is similar. First, the T or cross is screwed upon its mounting pipe, i.e., the surface pipe or the casing. Next the tapered plug is installed and the pipe which is to be secured is inserted in such manner that the outer ring (7 in the lower joint) is positioned just below the termnial position of the balls. Next, the balls are placed in the positions shown peripherally about the tapered surface and the outer wall of the pipe. By moving all of the balls downward along the taper to the same corresponding positions while at the same time permitting transverse movement of the pipe, the pipe will be automatically centered within the tapered plug.

Locking plug (14 in the lower figure) is next inserted and is screwed farther and farther into the tapered plug. As its lower inclined surface 13 impinges upon the balls 12, it forces them down along the tapered surface 11. Being squeezed between the tapered surface and the wall of the pipe, they begin to deform the pipe wall and partly imbed themselves therein as indicated at 24. After they have thus deformed the pipe wall the desired amount, movement of the locking plug is stopped and the assembly is complete.

Although I have illustrated my invention by one particular illustrative embodiment thereof, the invention is not limited in its application to the specific apparatus and particular arrangement therein disclosed. Various applications, modifications and arrangements of the invention will readily occur to those skilled in the art.

What is claimed is:

1. Apparatus comprising a first pipe, a plug defining a tapered opening therethrough mounted upon said first pipe, a second pipe within said first pipe and extending through said tapered opening, said second pipe coextending with said first pipe to form an annular space between said pipes and substantially closed at one end by said plug, a plurality of balls disposed peripherally about said second pipe and in contact with the tapered surface of said opening and with the outer surface of said second pipe, a sleeve mounted upon said second pipe at a point slightly below the point at which said balls contact said second pipe, said sleeve being of slightly smaller outside diameter than the smallest inside diameter of said tapered plug, and means for forcing said balls longitudinally along said tapered surface and said second pipe thereby to force said balls partly into the wall of said second pipe at a point immediately adjacent the end of said sleeve and lock said first pipe, said plug, said balls and said second pipe together.

2. Apparatus comprising a first pipe, an insulating plug defining an opening therethrough mounted upon said first pipe, a hardened member mounted within said opening and having peripheral contact with the inner surface of said plug, said hardened member having a tapered inner surface therethrough, a second pipe within said first pipe and extending through said tapered member, said second pipe coextending with said first pipe to form an annular space between said pipes and substantially closed at one end by said plug, a plurality of balls disposed peripherally about said second pipe and in contact with the tapered surface of said member and with the outer surface of said second pipe, a sleeve mounted upon said second pipe at a point slightly below the point at which said balls contact said second pipe, said sleeve being of slightly smaller outerside diameter than the smallest inside diameter of said hardened member, and means for forcing said balls longitudinally along the tapered surface'of said hardened member and said second pipe thereby to force said balls partly into the wall of said second pipe and lock said first pipe, said plug and hardened member, said balls and said second pipe together.

References Cited in the file of this patent UNITED STATES PATENTS Re. 19,910 Parker Mar. 31, 1936 1,036,547 Bell Aug. 27, 1912 1,337,288 Strichler Apr. 20, 1920 1,932,570 Black Oct. 31, 1933 2,182,797 Dillon Dec. 12, 1939 2,728,396 Carpenter Dec. 27, 1955 2,757,738 Ritchey Aug. 7, 1956 2,809,699 Battle Oct. 15, 1957 2,812,818 Brusco Nov. 12, 1957

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