US3004605A - Paraffin scraper and rod guide - Google Patents

Description

Oct. 17, 1961 P. POLSON PARAF'FIN SCRAPER AND ROD GUIDE Filed D60. 12, 1958 m m w m m n 0 3 a; O 7 P 5 747/027 2 I 4 u i! a g P F Y B m 3. 4 E M E w VWLW x H & M 3

ATTORNEY This invention relates to oil well pumping equipment, and it has particular reference to paraffin scrapers for 1 preventing or minimizing the accumulation of parafiin deposits on the inner surfaces of the well tubing during pumping operations.

A related device is shown in my Patent No. 2,772,741, dated December 4, 1956.

An object of the invention is to provide a device which effectively prevents static deposits of paraffin in the tubing and affords an efiicient guide for sucker rods operating therein.

Another object of the invention is to provide a simple and economical structure which can be installed along the sucker rod at spaced intervals, as desired, and arranged thereon at diiferent radial positions with respect to each other so as to insure the maximum efiiciency in operation.

Another object of the invention is to provide a parafiln scraper and sucker rod guide having a minimum of parts which reduces the cost of fabricating the device and affords a structure which is not readily destructible and is not likely to become dislodged and fall into the well to impair the pump or hinder its operation.

Another object of the invention is to provide a paraffin scraper and sucker rod guide which is so constructed that its presence at longitudinally spaced intervals along the sucker rod will not excessively restrict the flow of the oil through the tubing 0r unnecessarily burden the pump operating mechanism with its weight.

A further object of the invention is to provide a combined paraffin scraper and rod guide which can be so arranged and spaced along the rod as to effectively scrape the inner surface of the tubing on each stroke of the pump while at the same time preventing the rod from contacting the tubing wall.

The invention will be readily understood by referring to the following description and the accompanying drawing, in which:

FIG. 1 is a sectional elevational view, taken on a median line, showing a plurality of scraper and guide units embodying the invention operatively connected to a sucker rod disposed within a Well tubing;

FIG. 2 is a sectional plan view taken on the lines 2-2 of FIG. 1;

FIG. 3 is a sectional plan view taken on the lines 3-3 of FIG. 1; and

FIG. 4 is a fragmentary sectional elevational view on an enlarged scale, taken on a median line, showing a portion of the sucker rod and one of the scraper and guide units.

Referring to FIG. 1 of the drawing, the numeral 1 designates a well tubing. A sucker rod 2, used to operate a well pump (not shown), is arranged concentrically within the tubing 1 and is movable reciprocally therein. A plurality of scraper and guide units embodying the invention, which are indicated generally by the numeral 3, are attached to the rod 2 at longitudinally spaced intervals and slidably engage the inner wall of the tubing 1.

As shown in FIGS. 2 to 4, the scraper and guide units each include a band 4, which is split longitudinally at 5. The band 4 surrounds the rod 2 and is secured thereto by press fit,

A pair of spacer bars 6 are arranged parallel to each other and to the rod 2, and are rigidly secured, as by welding, to the peripheral surface of the band 4 on opposite sides thereof, so that their lower ends depend below the band 4, as shown in FIGURES l and 4. The spacer bars 6 are rectangular in transverse section, and have chisel-edged end portions 7 on adjacent ends thereof for use as guides, for guiding the scraper and guide unit 3 into the tubing 1. One of the spacers bars 6 is connected to the ban-d 4 adjacent the gap 5 thereof, whereby the gap 5 is bridged.

An annular scraper 8, which has an outside diameter approaching the inside diameter of the tubing 1, is arranged concentrically relative to the band 4, and is rigidly connected to the spacer bars 6 opposite the band 4, as by welding. The scraper 8 loosely engages the tubing 1.

The scraper 8, which is narrower than the band 4, is initially split longitudinally at 9. The scraper 8 is first pressed in position about the band 4 and the spacer bars 6, after which it is secured to the spacer bars 6 by welding. Finally the gap 9 of the scraper 8 is closed by filling it with weld metal and grinding the adjacent peripheral surface of the scraper 8 to remove excess metal.

In operation, the scraper and guide units 3 are attached to the sucker rod 2, which is used to operate the well pump (not shown), and are movable reciprocally therewith, whereby the annular scraper 8, which loosely engages the tubing 1, is caused to scrape the inner wall of the tubing 1 free of deposits of paraflin and the like.

The scraper and guide units 3 are also operable as guides whereby the sucker rod 2 is adapted to be maintained in its concentric position relative to the tubing 1, independently of the curvature or inclination of the well bore.

The spacer bars 6 maintain the annular scraper 8 in spaced apart relation to the band 4 and the sucker rod 2, whereby spaces are provided in the annulus between the annular scraper 8 and the band 4, on opposite sides of the scraper bars 6, for the passage of well fluids upon reciprocal movement of the sucker rod 2 and the scraper and guide units 3 in the tubing 1.

The chisel edged end portions 7 of the spacer bars 6 are useful as guides, for guiding the scraper and guide units 3 into the tubing 1.

The invention may be modified in various ways without departing from the spirit and scope thereof.

What is claimed is:

The combination of a well tubing, a pump rod arranged concentrically therein and movable reciprocally thereof, and a combined parafiin scraper and rod guide unit secured to the rod and slidably engaging the inner wall of said tubing, the scraper and guide unit comprising a band press fitted on said rod, a pair of diametrically opposed spacer bars arranged parallel to each other and to the rod and secured to the peripheral surface of said band on opposite sides of said rod, the lower ends of said bars depending below said band, and having opposingly bevelled lower ends, and an annular scraper, narrower than said band, embracing said bars and said band, and rigidly secured to said bars opposite said band whereby the said spacer bars extend below said scraper for guiding said unit into a well tubing.

References Cited in the file of this patent UNITED STATES PATENTS 1,770,207 Helmling July 8, 1930 2,058,331 Long Oct. 20, 1936 2,244,104 Fitzpatrick June 3, 1941 2,402,345 Ratigan June 18, 1946 2,702,083' Wagner Feb. 15, 1955- 2,772,741 Polson Dec. 4, 1956

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