US2175770A - Paraffin scraper - Google Patents

Description

Oct. 10, 1939. s. v. DODSON PARAFFIN SCRAPER Filed Nov. 16, 1938 Patented Oct. 10, 1939 UNITED STATES 'PATE Nr OFFICE Claims.

This invention relates to a parafiln scraper. More particularly, the invention relates to a device for cleaning well tubing and especially the removal of accumulated parafiin from the tubing of oil and gas wells.

The improved scraper forming the subject matter of this application is adapted to be suitably connected in the sucker rod at intervals and as the conventional sucker rods are formed in sections, the improved scrapers may to advantage, though not necessarily, be connected at the joints between the sucker rod sections.

A primary object of this invention is the pro- Vision of a parafiin scraper which, when incorporated in the sucker rod of an oil well in multiple will positively preclude the accumulation of paraflin on the wall of the tubing within which the sucker rod reciprocates.

A iurther object of the invention is the provision ofa paraflin scraper which is relatively simple in construction, durable and eflicient in operation, and which is factored at relatively low cost.

For a more complete understanding of the nature and objects of ,the invention, reference will be had to the following detailed description, taken in connection with the accompanying drawing, wherein Figure 1 is a side elevational view of the improved scraper, in accordance with a preferred embodiment thereof, a portion of the lower threaded end being broken away.

Figure 2 is a similar view as seen in a direction of right angles to that of Figure 1.

Figure 3 is a top plan view of the scraper in the position illustrated in Figure 1.

Figure 4 is a transverse section in a plane represented by the line 4-4 in Figure 1.

Figure 5 is a broken central vertical section of an oil well tubing, showing the improved scrapers operatively associated with the sucker rod in elevation.

Referring now in detail to the drawing, by reference characters, and wherein like characters designate like parts, S designates the improved scraper, T the well tubing, and R the sucker rod which in practice reciprocates within the tubing.

The scraper S is a unitary structure and comprises the scraper section III, an internally threaded end section II, and an externally threaded opposite end section l2, the latter end section being spaced from the scraper section In by the cylindrical sections l3 and II.

The scraper section In embodies asubstantially cylindrical core I! from which project the capable of being manur tube engaging projections l6 and I1 preferably integral with the core l5 as indicated in Figure 4.

I-he projections I6 are substantially half diamond-shaped in plan and the projections I! are diamond-shaped in plan.

The projections I 6 are arranged in diametrically opposed pairs adjacent the opposite ends of the core and with their opposed edges l8 co-planular with the ends of the core l5.

The projections I! are diametrically opposed 10 with their minor axes parallel with the edges l8 and substantially midway the length of the core l5. Thus there are four projections l6 and two projections I7 and the outer surfaces of all of the projections are concentric with the core l5 l5 and of a diameter substantially equal to the well tubing.

The projections I 6 have angularly disposed edges I9 and the projections I! have angularly disposed edges 20.

The edges l8 of projections l6 being at right angles to the axis of reciprocation of the scraper in use act as scrapers and the angular or diagonal edges l9 and 20 act as wedges to cut any accu- 'mulated paraflin from the tubing wall, these latter edges also acting as scrapers.

As is clearly indicated in Figs. 3 and 4, the scraping edges l8 of the projections l6 are of substantial arcuate extent, each extending approximately 45 degrees of the circumference of 0 the core 15. It is to be also noted that the projections l! at their minor axes also each extend approximately 45 degrees of the circumference of the core l5 and that the apices of the projections 5 are in vertical alinement and approximately midway of the lateral apices of the projections l1 and that the vertically alined apices of the projections I! are substantially midway of the spaces between the projections I 6.

In other words, the projections l6 and I1 pro- 40 vide continuous scraping and wedging edges circumferentially of the core l5 and the projections so disposed provide relatively wide intersecting passages 2| which freely permit parailin and well fluids to pass between the projections from one end of the core to the other on either the up or down stroke of the pump.

It will be further noted that the adjacent wedging edges l9 and 20 are substantially parallel thereby, providing passages 2| which are of substantially uniform width whereby no ob- 'structions are oifered to the free passage of paraflin and well fluids between the scraping and wedging projections.

The manner in which-the improved scrapers 2 are intended to be used is illustrated by way of example in Figure 5 wherein the scrapers S are interposed in the sucker rod R at desired intervals, the scrapers being connected to the sucker rod sections by suitable connectors 23 and 24.

As will be seen upon inspection of Figure 5, the concentric outer surfaces of the projections I6 and I1 only engage the inner 'wall of the tubing T and as the sucker rod R is vertically reciprocated, the scraping and wedging edges l8, l9 and'2ll of the projections l6 and I1 will prevent the accumulation of parafl'in on the tubing wall and by spacing the scrapers lengthwise of the sucker rod substantially equal to the amplitude of reciprocation, the entire length of the tubing wall will be kept clean.

During the reciprocation of the scrapers the passages M will permit the free flow of paraffin and well fiuids past the projections l6 and I1.

Thus it will be seen that the improved scrapers in accordance with this invention effectively function to keep the tubing wall free from paraffin accumulation and that the relative simplicity and ruggedness of the structures well adapts them to this particular use.

While I have disclosed but bodiment of the invention, sidered as illustrative only, the scope of the invention subjoined claims.

What I claim and desire to secure by United States Letters Patent is:

l. A scraper for a tubing of an oil well comprising an elongated cylindrical member, a pair of diametrically opposed projections adjacent each end of the cylindrical member and having horizontal co-planular scraping edges, each of the projections having wedging edges obliquely disposed with respect to the axis of the cylindrical member, and a pair of diametrically opposed projections intermediate the first projections and each having a plurality of wedging edges substantially parallel with the respective adjacent edges of the first projections.

2. A scraper for a tubing of an oil well comprising a cylindrical core, projections on the core adjacent each of the opposite ends thereof, each of the projections presenting a horizontal scraping edge and a pair of wedging edges converging to a point on the core inward of the respective end thereof.

3. The structure defined in claim 2 together with additional projections on the core intermediate the first projections, the last named projections each presenting scraping and wedging edges, substantially parallel with the adjacent converging edges of the first named projections.

a single specific emsame is to be conand not restrictive, being defined in the 4. A scraper for a tubing of an oil well comprisinga cylindrical core, a pair of diametrically opposed projections on the core adjacent each end thereof, a pair of diametrically opposed projections on the core intermediate the first projections, the projections having substantially parallel opposed scraping and wedging edges defining intersecting passages of substantially uniform width extending from one end of the core to the other.

5. The structure defined in claim 4 wherein the first named projections have horizontal scraping edges substantially co-planular with the respective ends of the core.

6. A scraper for a tubing of an oil well comprising a cylindrical core, a pair of projections on the core adjacent each end thereof and a pair of projections on the core intermediate the first projections, the first projections each having scraping and wedging edges converging toward the central transverse plane of the core, and the second projections having scraping and wedging edges converging toward the opposite ends of the core.

7 The structure defined in claim 6 wherein the first projections are substantially of triangular form in plan and in which each presents a horizontal scraping edge, and wherein the second projections are diamond shaped in plan with their minor axes in said plane.

8. A scraper for a tubing of an oil well comprising a cylindrical core, a pair of diametrically opposed projections on the core adjacent each end thereof, said projections each having a horizontal scraping edge extending circumferentially of the core through an angle of substantially 45 degrees and having a pair of wedging edges converging toward the central transverse plane of the core, a pair of diametrically opposed projections on the core intermediate the ends thereof, each of the second named projections being diamond shaped in plan, the second named projections having their major axes parallel with the axis of the core and substantially midway of the adjacent ends of the horizontal scraping edges and with their minor axes in said plane.

9. The structure defined in claim 8 wherein said minor axes each extend through an angle of approximately 45 degrees.

10. A scraper for a tubing of an oil well comprising a cylindrical core, a pair of projections each of triangular form of the core adjacent each end thereof, and a pair of projections each of diamond shape in plan on the core intermediate the opposite ends thereof.

SIDNEY V. DODSON.

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