US2733767A - Apparatus for removing paraffin from - Google Patents

Description

1956 R. H. SAPPINGTON 3 APPARATUS FOR REMOVING PARAFFIN FROM OIL WELLS I Filed NOV. 23, 1951 5 "it I 2 i i ATTORNEY IN VENTOR United States Patent APPARATUS FOR REMOVING PARAFFIN FROM OIL WELLS Ransom H. Sappington, WestBranch, Mich.

Application November 23, 1951, Serial No. 257,726

1 Claim. (Cl. 166-176) duction.

It is well-known to those familiar with the operation of oil'wells that the flow' in many wells gradually becomes restricted due to the fact that parafiin and other similar constituents found in crude oil gradually accumulate in semi-solid form on the inside wall of the pumping tubing. This accumulation, more or less rapid, depends on conditions and varies according to the type and quantity of oil produced, restricts the area through which the pump must force the oil from the bottom of the well, and sets up a resistance to flow, placing heavy stresses on all pumping equipment, thus slowing down the pumping operation, and consequently curtailing production.

The parafiin accumulation of the constituents above referred to, usually occurs at a point where the combination of hydrostatic pressure and temperatures brings about a favorable condition for precipitation of the solid paraifin from the oil, and the removal of this accumulation etc. is essential to maximum production whenever it restricts the flow.

At the present time, it is conventional practice, when cleaning pumping wells, to shut down the pump, pull and disconnect enough of the sucker rod to permit a parafiin cleaning tool of the hook and washer type to be inserted and lowered a distance into the paraffin accnmulation, and then attempt to raise the tool and scrape a section of the parafi'in loose, this operation being repeated until the entire well has been cleaned, and where the deposit is quite heavy and the operator attempts segments as the device is actuated, so that it can be readily drawn upwardly with the sucker rods.

With the above and other objects in view, the present invention consists in the combination and arrangement of parts, hereinafter more fully described, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportion, and minor details of construction, without departing from the spirit, or sacrificing any of the advantages ofthe invention.

In the drawing:

Fig. 1 is a part sectional view of an oil well with my paraflin removing apparatus in place therein.

Fig. 2 is an enlarged, fragmentary, sectional view illustrating the removal of the paraffin accumulation.

Fig. 3 is a transverse, sectional plan view taken on the line 3-3 of Fig. 2. V

Fig. 4 is an enlarged, perspective view of the cutting apparatus.

Referring now more particularly to the drawing in which I have shown the preferred embodiment of my 1 ground level and the'lower to scrape a length of paraffin accumulation greater than the tool can handle, the washer will bend and then must be withdrawn and a new washer substituted therefor, so in addition to the loss of pumping time, there is the added labor, expense and time incident thereto.

There are also various forms of scraping devices at present on the market, and these are clamped to the sucker rods and scrape the wall of the tubing as the pump is operated, but these devices become loose and clog, bend and become wedged in the pipes, making it necessary to perform a stripping job which is both hazardous and expensive, and I have therefore perfected a very simple, practical and inexpensive apparatus which requires a minimum cessation of the pumping operation, which can be raised to clearly cut the parafiin and similar constituents from the casing, cutting and breaking it into invention, the numeral 10 indicates the outer casing of an oil well. This can be of any desired size and a pump tubing 11 is suspended in said casing, the upper end of said tubing projecting a short distance above the end extends downwardly to the bottom of the well.

This pump is of standard construction and is made up of aplurality of pipe sections secured together by couplings 12, said tubing forming a conduit for the oil as usual. The casing head 14 has threaded connection with the upper end of the outer casing 10 and includes a stufiing box 15 through which the sectional pump rod 16 extends for connection to a suitable pump actuating power plant (not shown) so that the rod may be reciprocated to pump the oil from the well, and a dis charge spout 17 opens into the upper end of the tubing 11 and leads to a tank or other storage receptacle (not shown) and into which the oil is pumped or directed.

My cutter apparatus C is clearly shown in Figs. 2, 3 and 4 of the drawing, and comprises a cylindrical shell or member 18 formed of relatively thin metal of predetermined length, and formed with a plurality of relatively thin, radiating wing sections 19 Welded to the shell 18 and to the sucker rod 16 respectively to form a rigid connection. These wings 19 extend beyond the ends of the cylindrical shell 18, being curved as at 20 and are preferably sharpened as at 21 so that they readily cut the parafiin accumulation at predetermined points intermediate the circumference of the tubing.

The upper and lower ends of the cylindrical shell 18 are also preferably sharpened so that a light accumulation of parafiin is very easily removed, and when the accumulation is heavy, the paraflin is scored or cut by the wings 19 prior to engagement by the edge of the cylinder proper, thus very materially lessening the force necessary to etfect complete removal of the circumferential form of paraffin accumulation.

When the cutter apparatus C remains in the well, it is normally positioned slightly below the point or area of paraffin accumulation P, and when it is desired to clean the tubing, the pump rod 16 is raised a distance sufficient to cleanly scrape all paraflin accumulation from the tubing.

When the apparatus is inserted and removed each time the well is cleaned, the parafiin deposit will be cut Where the paraffin deposit is quite heavy, the projecting wings 19 are of prime importance because the paraffin, when cut, will tend to retain its cylindrical shape or form, and this is-eliminated in the instant construction in which the cylindrical shape is first scored or cut, and the strips are then removed and broken by the ends of the cylinder, said'strips being drawn upwardly with the pump rod and can then be disposed of as desired. It

is merely necessary to raise the rod so that the cutter member C will travel up through that section of the tubing where the accumulation or deposit of paraffin occurs. This cuts the paraffin free, and it is then drawn upwardly by the scraper 22 as the pump rod is withdrawn, this scraper being of standard design readily available on the open market and is designed to minimize resistance to the upward flow of the oil.

When the tubing is clean, the pump will now function at full capacity, and there is very little lost time. p I wish to direct particular attention to the fact that it is not necessary to remove the cutter member from the pump rod because when once installed in position at a level below the point where the accumulation of paralfin occurs, there it remains and is used only when the parafiin accumulation becomes sufficiently thick to restrict the flow.

If desired, a plurality of these cutter members can be mounted on the pump rod at closely spaced points so that each stroke of the pump covers a distance greater than the length of the cutter so that the entire length of tubing is kept free and clear, and the size and shape of the cutters insures a minimum of wear on both the tubing and the cutters. 7

From the foregoing description, it will be obvious that I have perfected a very simple, practical, inexpensive and efiective apparatus for cutting, breaking up and removing the parafiin accumulation in oil wells.

What I claim is:

The combination with the cylindrical pump tubing of an oil well and an oil well sucker rod disposed therein, of a relatively thin Walled cylindrical shell concentric with said rod, the rod extending entirely through the shell and the peripheral wall of said shell being of substantially the diameter of the inner diameter of said pump tubing so as to be in engagement therewith, said shell being formed with an outwardly beveled annular end blade thereon in engagement with the wall of the tubing over its entire extent to scrape a paraffin deposit entirely from the inner peripheral wall of the tubing as the rod is actuated longitudinally therein, and a plurality of radial scoring vanes of a thickness substantially no greater than the thickness of the wall of said shell extending the length thereof and rigidly connecting said shell and said rod along the entire length of said vanes, the ends of said vanes extending beyond both ends of said shell and curving inwardly to said rod, and being at all times disposed inwardly of the cutting edges on said shell, the outer curved portions of said vanes having sharp blades thereon for scoring said parafiin deposit ahead of said shell. 2

References Cited in the file of this patent UNITED STATES PATENTS 1,720,049 I Miller July 9, 1929 1,847,985 Sawyer Mar. 1, 1932 2,274,107 Sweet Feb. 24, 1942 2,354,245 Corbosiero July 25, 1944

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