US3085629A - Paraffin control coupling - Google Patents

Description

April 1963 D. A. HENDERSON 3,085,629

PARAFFIN CONTROL COUPLING Filed Aug. 4, 1960 SOURCZ 0F PRESSl/R/ZED FLU/D a will-- amt gr F ,a 3 INVENTOR: J Don Henderson.

United States Patent Oce 3,085,629 Patented Apr. 16, 1963 3,085,629 PARAFFIN CONTROL COUPLING Don A. Henderson, Levelland, Tex., assignor of onefourth to Wendell Cofiee, one-fourth to Travis C. Henderson, and one-fourth to Doyle Henderson Filed Aug. 4, 1960, Ser. No. 47,410 1 Claim. (Cl. 166-224) This invention pertains to oil wells and more particularly to means for controlling paratfin accumulation within wells.

With the production of oil there is often a problem of parafiin accumulation upon the inside of the tube through which the oil flows from production strata to the surface of the ground. The oil in the strata is at elevated temperatures and the paraflin is melted. The parafiin cools as it journeys upward and there is a point within the well where the parafiin begins to precipitate upon the walls of the tube.

I have invented a control coupling to be inserted into the production tube just below the point where the paraffin begins to accumulate. This point will be defined for each well and about the same for all wells within a field. The coupling permits a free flow of oil through the tube and has a valved opening through the wall thereof. The valve is spring loaded so that it normally is closed as the oil flows to the surface. However, introduction of liquid at excessive pressure opens the spring loaded valve. A valve at the bottom of the well prohibits oil from flowing back into the strata. By this means hot oil or solvent may be introduced at the top of the well so that it will flow within the well over .that portion where the paraflin accumulates.

\An object of this invention is to provide a control coupling in a production tube for expelling liquid from the production tube.

Another object of this invention is to provide such a control coupling which is small in diameter.

A further object is to provide such a control coupling that will spray the liquid from the production tube in a plurality of directions.

A further object is to provide a method of applying corrosion inhibitor to a well.

Still further objects are to achieve the above with a device that is sturdy, compact, durable, simple, and reliable, yet inexpensive and easy to manufacture.

The specific nature of the invention as Well as other objects, uses, and advantages thereof will clearly appear from the following description and from the accompanying drawing, in which:

FIG. 1 is an axial schematic view showing a well with one embodiment of the invention.

FIG. 2 is a perspective view in half section showing the control coupling.

FIG. 3 is a cross sectional view taken on line 3-3 of FIG. 2.

FIG. 4 is an enlarged fragmental section showing in detail one valve and its valve seat.

As seen in the drawing, the control coupling is b asically a short tubular element which has threads 12 at both ends so that it may be attached into the production string or tube. Enlarged portion 14 is adjacent to the upper threads. A plurality of symmetrical spaced ports 16 is within this portion. The ports lead from the interior bore of the control coupling 10 to shoulder 17 defining lower portion of the annular enlargement 14. The shoulder is normal to the axis of the coupling. The

bottom of the ports are beveled to form valve seat 19. Valve ring 18 encircles the tool immediately below the shoulder. A ball valve 20 for each port is embedded in the upper surface of the ring. The valve ring is biased against the shoulder and therefore, the individual valves are biased against their seats by helical spring 22. The ring has an axial notch 24 in the interior surface thereof. Bolt 26 projecting from the body of the coupling cooperates with the notch to prevent the ring from rotating. The spring 22 is held from the bottom by the nut 28 which is threaded upon extended lower threads 12. Set-screw 30 locks the nut in the desired position.

The coupling is installed in place in string of production tubing 32 which is located in casing 34. Sucker rod 36 extends within the production string to pump mechanism 38 at the bottom of the well. The pump cooperates with standing valve 40 to prevent any flow of liquid downward within the well. Seal 42, located on the top of the well, causes all oil to flow through the pipe 44. Conventional mechanism is employed to reciprocate the sucker rod. Connection 46 leads into the pipe 44 connecting it to a source of pressurized fluid.

When the paraffin has reached an undesirable accumulation the pumping operation is stopped, valve 48 in the pipe 44 is closed, and the valve in the connection 46 is opened. Thus, the source of the pressurized fluid is connected to the production string. The pressure upon the source of fluid is high enough to force the valve ring 18 away from the shoulder permitting a flow through the ports 16. The flow of pressurized fluid can be controlled by the rate in which it is injected. The source of pressurized fluid is adapted to pump either hot oil to melt the paraffin or a solvent to dissolve the parafiin.

The control coupling will also operate as a safety valve to relieve excessive pressures should they develop at that point during operation.

Corrosion inhibitor may be introduced into the well in a conventional manner. After introduction the coupling will aid in distribution. All openings at the top of the well are closed and the pump operated. The only escape for the inhibitor-oil mixture in the well is through the coupling 10 below the ground. Thus, the inhibitor is well distributed over the tubing and casing. As the fluid leaves the coupling, it is sprayed from the various valves 20 in multi-directional sprays so that it also runs down the casing.

In this unique design the diameter of the coupling is small. The diameter of this control coupling is no greater than the diameter of the couplings by which the elements of the production string are connected. The coupling of inherent rugged design has no projections which may be broken off by rough handling.

It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction, materials, and arrangement within the scope of the invention as defined in the appended claims.

I claim as my invention:

A control coupling connected within a string of production tubing of an oil well, said control coupling comprising: a tubular element, a portion of said tubular element being enlarged, said enlarged portion terminating with a shoulder with a surface which lies in a plane normal to the axis of the tubular element, .a plurality of ports extending from within the bore of the tubular element to the surface of the shoulder, .the shoulder terminal of each port forming a valve seat, a ring slidably encircling the tubular member element, a ball valve seatable upon each of said valve seats for each of said ports, each of said ball valves embedded in the surface of said ring, an axial slot in the inner surface of the ring, a bolt secured to and extending from the surface of the tubular element, said bolt slidably mounted within the slot so that the ring is restricted to translational movement, said tubular element having threads on one end thereof, a nut threaded on the threads of the tubular element, and a spring encircling the tubular element between said nut and said ring, said spring biasing said ball valves against their seats.

References Cited in the filc of this patent UNITED STATES PATENTS

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