US3773441A

US3773441A - Combination sand bailer and fluid pump with automatic grit separator and lubricator

Info

Publication number: US3773441A
Application number: US00144918A
Authority: US
Inventors: A Schertz
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-05-19
Filing date: 1971-05-19
Publication date: 1973-11-20
Anticipated expiration: 1990-11-20

Abstract

An automatic grip separator and lubricator for a tubing pump having reservoir means for automatically supplying grit-free fluid to the interface between the pump barrel and plunger. The vertically elongated fluid reservoir opens at its lower end into the stream of fluid being pumped effective to return grit gravitating from quiescent fluid in the reservoir. Air trapped in the top of the reservoir provides a resilient cushion to aid seepage of clean fluid through a filter cartridge and a passage leading to the interface between the barrel and plunger. Foreign matter separation is primarily by gravity and secondarily by filter. The dual-action grip separator is so effective that the pump can function as a sand bailer initially and then phase into the fluid pumping operation as the sand supply diminishes.

Description

[ Nov. 20, 1973 COMBINATION SAND BAILER AND FLUID PUMP WITH AUTOMATIC GRIT SEPARATOR AND LUBRICATOR [76] Inventor: Arthur R. Schertz, 202 Supply Row, Taft, Calif. 93268 [22] Filed: May 19, 1971 [21] Appl. No.: 144,918

[52] US. Cl 417/554, 92/78, 92/86.5, 92/ 182 [51] Int. Cl. F15b 21/04 [58] Field of Search 417/554, 366, 53; 92/86.5, 87, 78, 79, 81, 182; 166/1052, 105.3

[56] References Cited UNITED STATES PATENTS 3,132,568 5/1968 Strader 92/78 1,451,814 4/1923 Cullinan.... 92/246 1,212,294 1/1917 Walker 92/246 1,548,805 8/1925 Mowrey 417/554 1,948,325 2/1934 Anderson et a]. 166/1052 2,821,933 2/1958 Brennan 166/1053 FOREIGN PATENTS OR APPLICATIONS 729,319 5/1955 Great Britain 92/78 Primary ExaminerC. J. l-lusar Assistant Examiner-Leonard Smith Attorney-Sellers and Brace [57] ABSTRACT An automatic grip separator and lubricator for a tubing pump having reservoir means for automatically supplying grit-free fluid to the interface between the pump barrel and plunger. The vertically elongated fluid reservoir opens at its lower end into the stream of fluid being pumped effective to return grit gravitating fromquiescent fluid in the reservoir. Air trapped in the top of the reservoir provides a resilient cushion to aid seepage of clean fluid through a filter cartridge and a passage leading to the interface between the barrel and plunger. Foreign matter separation is primarily by gravity and secondarily by filter. The dualaction grip separator is so effective that the pump can function as a sand bailer initially and then phase into the fluid pumping operation as the sand supply diminishes.

11 Claims, 4 Drawing Figures United States Patent [1 1 Schertz Nov. 20, 1973 COMBINATION SAND BAILER AND FLUID PUM? WITH AUTOMATIC GRIT SEPARATOR AND LUBRICATOR This invention relates to tubing pumps, and more particularly to a unique construction operable as a combined bailer and fluid pump and incorporating highly effective means functioning automatically to maintain the plunger lubricated with clean gritfree 1 portions of the fluid being pumped.

Tubing pumps are in wide use to pump petroleum or other fluids'from deep wells, the pump being located in the lower portion of tubing through which the fluid is elevated. The pump itself is constructed in various ways but essentially includes a barrel along which the pump plunger is reciprocated by a rod extending upwardly through the tubing to a walking beam or the like driver at ground level. The plunger is equipped with sealing rings at its opposite ends intended to exclude foreign matter in the fluid being pumped from entering the interface between the plunger and barrel. However, despite the efforts of many designers, sand and gritty material inevitably migrate into the interface causing serious damage to the plunger and barrel, and necessitating withdrawal of the pump from the well for servicing and the replacement of damaged parts. The problem is very serious in many areas and it is not uncommon for pumps to become inoperable in as short a period as a few hours and frequently for not more than one or two days before it is necessary to replace the damaged pump with a reconditioned pump while the first pump is removed to a service station for rebuilding.

The foregoing and the like serious and costly shortcomings of prior tubing pumps are substantially eliminated by the present invention utilizing simple, readily effected changes in conventional tubing pumps of any of a wide variety of designs. Typically, these changes are confined to the pump plunger which is modified to include a vertically elongated fluid reservoir open to the main flow passage through the plunger and having one or two small bore outlet passages from its upper end into the interface between the barrel and plunger. Desirably, a filter for fine grit and sand is interposed between the reservoir inlet and the outlet to the interface and charged with filtering media capable of withstanding higher well temperatures and effective to remove finer grit and sand from fluid enroute to the interface. Since a slow seepage of fluid to the interface suffices to maintain the interface'charged with fluid under the prevailing well pressure, the-main body of fluid in the reservoir remains quiescent providing highly favorable conditions under which gritty and sandy material gravitates back into the main fluid stream through the inlet at the bottom of the reservoir. Any fines not gravitating out are removed by a high efficiency final filter cartridge. Typically and as herein disclosed, the filter cartridge comprises a tubular assembly supported lengthwise of the reservoir and designed to cooperate with the reservoir wall to provide a dead air chamber enclosing a cushion of air acting to absorb changes in pressure as the plunger reciprocates and effective to promote the seepage of clean filter into the interface to maintain the latter charged with clean lubricating fluid.

The invention pump and its grit separating action are so effective as to provide a highly reliable combined sand bailer and fluid pump. For example, under highly adverse conditions the pump can be used initially as a sand bailer and, as the proportion of sand decreases,

Accordingly, it is a primary object of the present invention to provide a new and improved tubing pump operable both as a sand bailer and a fluid pump.

Another object of the invention is the provision of a unique tubing pump incorporating therein separator means for removing sand and gritty material from a portion of the fluid being pumped and to utilize the clean fluid to lubricate the pump and particularly the barrel and plunger thereof.

Another object of the invention is the provision of an improved tubing pump and method of operating the same to supply grit and sand free portions of the fluid being pumped to the interface between pump components.

Another object of the invention is the provision of a tubing pump utilizing metallic sealing rings at the opposite ends of its plunger together with means for lubricating these rings using grit free portions of the fluid being pumped.

Another object of the invention is the provision of a tubing pump capable of operating under geothermal conditions and including means therein for furnishing a continuous supply of filtered lubricating fluid from the fluid being pumped to lubricate the plunger and metallic seal rings at either end thereof.

Another object of the invention is the provision of an improved tubing pump having a reservoir charged with clean fluid under the prevailing well pressure and having an outlet therefrom into the interface between the pump barrel and plunger.

Another object of the invention is the provision of a tubing pump functioning to provide a supply of substantially sand and grit free fluid withdrawn from the fluid being pumped and allowed to seep at the prevailing well pressure into the interface relatively moving pump components to lubricate the same.

Another object of the invention is the provision of a tubing pump equipped with a vertically elongated fluid reservoir in communication at its lower end with the fluid being pumped and in communication at its upper portion with the interface between the pump barrel and plunger and functioning to separate out a major portion of grit and sandy material by gravitation before conducting the same to the interface.

Another object of the invention is the provision of a tubing pump having associated with the barrel or plunger thereof an elongated quiescent body of well fluid under conditions conducive to the separation of sand and grit therefrom at a rate sufficient to replace fluid loss by migration from the interface between the pump barrel and plunger.

These and other more specific objects will appear upon reading the following specification and claims FIGS. 1a and 1b are cross-sectional views through the opposite ends of a tubing pump of one illustrative embodiment of the present invention; and

FIGS. 2a and 2b are fragmentary cross sectional views showing a high temperature sealing ring adapter for use at the opposite ends of the pump piston in lieu of the chevron type seal shown in FIGS. la,1b.

Referring to FIGS. 1a and 1b there is shown an illustrative embodiment of the tubing pump, designated generally 10, comprising a tubular barrel 11 enclosing a pump plunger 12 having a close sliding fit with the interior surface of the barrel. Pump is usually connected to the lower end of tubing suspended from the well head centrally through the well casing, not shown. TI-Ie tubular plunger 12 is reciprocated axially of barrel 11 in known manner by a pump rod 14 located centrally of the tubing and having its upper end connected to means such as a walking beam for reciprocating the same.

The lower end of plunger 12 comprises a pair of

valve body members

18,19 held assembled by threads and supporting a ball valve 21 therebetween normally seated on seat 22. Theaded into the lower end of member 19 is a bushing 24 for holding a series of sealing rings 25 assembled to the lower end of the plunger. A similar set of sealing rings 26 is held assembled to the upper end of the plunger by the tubular end cap 27. This end cap has a pair of flow outlet passages indicated by arrows 28, the lower end of the end cap being threaded to an adapter tube 29. The upper end of this adapter provides a seat for sealing rings 26 and its lower end is held assembled to the tubular main body 30 of the plunger by threads 31.

The foreign matter separator and automatic lubricating assembly for the pump is here shown as housed within the upper end of the plunger. However, it will be understood that the separator and lubricator could be housed within a suitably constructed chamber of the pump barrel 11 or the pump tubing without departing from the principles of the present invention. Desirably and as herein shown, the separator is located within the plunger since there is adequate space available there without restricting the free flow passage of the fluid being pumped and since the principles of the invention can be practiced most economically and simply in this manner.

Separator chamber is here shown as a vertically elongated annular chamber formed between the inner surface of plunger body 30 and an imperforate tube 41 having a press fit 42 within the lower end of adapter 29. Preferably the bore of tube 41 corresponds with the size of the flow passage 43 through adapter 29 thereby avoiding restricting the flow passage through the plunger. Although not so shown in FIG. 1a, it will be understood that tube 41 may extend throughout the major length of the plunger to provide a long separator chamber 40 maintained filled with quiescent well fluid through the sole inlet 45 provided at the lower end of tube 41. Preferably the lower end of this tube flares to minimize the interference with fluid flow upwardly through the tube during operation of the pump.

Mounted concentrically of tube 41 is a filter cartridge 46 the upper end 47 of which is here shown as having a suitable fluid tight connection with the lower end of bushing 29 such as a snug frictional fit. The lower end of the cartridge seats a well known cup-type sealing ring 48 providing a fluid seal with the inner surface of plunger body 30 and safeguarding against the passage of sand and grit.

The filter cartridge may be formed in any suitable manner, and as here shown, comprises inner and

outer sleeves

50,51 confining a mat of suitable high temperature filter media such as fiberglass. Outer tube 50 may be perforated throughout its length but inner sleeve 51 is free of perforations in its upper end portion to provide a dead air chamber 55. As here shown the upper third of the inner wall is imperforate with the result that the liquid in the reservoir and inwardly of tube 51 cannot rise above the uppermost ones of the perforations. However, fluid may flow through the filtering material throughout the full height of the filter cartridge and escape from the uppermost ones of the perforations in outer tube 50.

The only escape for the clean fluid from separator chamber 40 is through one or more small passages 58 here shown as of inverted L-shape. The longer leg comprising a slot crosswise of threads 31 at the upper end of plunger body 30 and the shorter leg opening radially into the interface between the exterior of the plunger 12 and the interior of barrel 11.

Before operation, it will be understood that the pump is installed in the well in the usual manner. As the lower end descends into the well fluid, the fluid passes upwardly through inlet passage 60 lifting ball valve 21 from its seat and flowing into the interior of the plunger. As the fluid rises it fills the central flow passage 43 as well as separator reservoir 40. It will be understood that before the plunger is assembled to barrel 11 the surfaces are thoroughly lubricated so that the interface of one or two thousandths inch between the plunger and the barrel is completely charged with lubricant or grease. The well fluid entering the separator chamber 40 fills the latter with the exception of the dead air chamber 55. The length of this chamber may be varied as desired by varying the portion of the upper end of inner sleeve 51 which is perforated. As here shown the perforations extend only through the lower two thirds of the sleeve but this distance may be widely varied to suit particular operating conditions.

Since the fluid in the upper portion of the well is normally in a quiescent condition, it is substantially free of foreign matter with the result that the initial charge of fluid entering chamber 40 is relatively free of sand or gritty material. However, any grit or foreign material present is filtered out since all fluid entering the chamber must pass through the filter cartridge before it can escape through passage 58.

After the pump has been installed, the plunger is reciprocated in the usual manner. During lowering of the plunger, ball valve 21 is forced to lift from its seat by fluid flowing upwardly therepast into the main body of the plunger. As the plunger starts its upward movement ball 21 seats and the fluid is lifted to the surface as other fluid enters the lower end of the well.

Initially and if the well is charged with sand, the pump will operate as a bailer to elevate sand to the surface. During this period it is possible fluid containing sand will enter the lower end of separator chamber 40. However, all fluid in this chamber remains substantially quiescent and in a static condition despite raising and lowering of the plunger. Accordingly solids and gritty material readily gravitate and escape into the main stream passing upwardly through tube 41, the escape of gritty material taking place through the inlet 45 where it is entrained and passes upwardly through 41. However, should lubricant escape past packing rings 25,26 the well pressure acting in the main flow passage as well as on the clean fluid in chamber 40 will cause seepage of clean fluid upwardly through passage 58 and into the interface between the opposite ends of the plunger. This seepage of new lubricating fluid between the pump surfaces is aided very materially by the resiliency W of the trapped body of air in dead air chamber 55. The

pressure in this chamber varies slightly during upward and downward movement of the plunger, the changing pressure in the trapped air acting as a spring cushion providing pulsing action on the trapped clean fluid. This pulsing action causes fluid to migrate through the filter material and upwardly through passage 58 into the interface.

During prolonged operation of the pump the supply of clean fluid in the separator chamber is replaced repeatedly but always with fluid from which foreign matter and gritty material have gravitated back into the mainstream through inlet 45, the only fluid used for lubricating purposes being the clean fluid withdrawn from the upper portion of reservoir chamber 40.

Referring to FIGS. 2a and 2b, there is shown an alternate construction differing from that just described only in the use of resilient metallic piston sealing rings ',26 in lieu of the chevron type sealing rings 25,26 shown in FIGS. la,lb. Accordingly the same reference characters distinguished by the addition of a prime have been employed to designate the similar components in the two embodiments of the invention. It will be noted that the sealing rings are seated in grooves formed in bushing 24 and in tubular end cap 27 at the opposite ends of pump plunger 12' and that these are the only components of the two pump assemblies of differing construction in addition to the sealing rings themselves required to convert the pump for use with the two types of sealing rings. The metallic sealing ring is preferable and has a substantially greater service life under certain operating conditions and particularly in higher temperature environments where chevron type sealing rings are not feasible. In certain deep wells or in thermal wells subject to steam flow metallic rings are found far superior and to have long life owing to the ample lubrication with grit free lubricant provided by the novel construction of the herein disclosed pump construction which makes possible the use of metallic sealing rings.

Although differing numbers of the rings 25',26 have been shown at the opposite ends of plunger 12', it will be understood that the number employed at either end can differ, or not, and that this is a matter of designers choice under the particular operating conditions. The operation of the pump shown in FIGS. 2a, 2B differs in nowise from that described above.

While the particular combination sand bailer and fluid pump with automatic grit separator and lubricator herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the detail of construction or design herein shown other than as defined in the appended claims.

I claim:

1. In a tubing pump for use in a well and of the type having a check valve-equipped tubular plunger having seal means encircling its opposite end portions and reciprocable axially of a tubular barrel for said plunger, that improvement for lubricating the interface between said plunger and said tubular housing with the fluid being pumped substantially free of grit and the like foreign matter which comprises: reservoir means for collecting and storing a continually replenished supply of clean oil from grit laden oil being pumped, said reservoir means including an elongated tube having its upper end secured in fluid-tight relation coaxially of and within the upper end portion of said plunger with the lower end portion in communication with a fluid flow passage interiorly of said plunger, said elongated tube cooperating with the interior sidewall of said plunger to form an annular reservoir for a quantity of trapped quiescent grit-free lubricating fluid from which grit gravitates back into the fluid being pumped and which quiescent-lubricating fluid is replenished as used from flow past the lower end of said elongated tube, means providing a main flow passage for conveying the fluid being pumped past the full height of said reservoir means which main flow passage is free of flow restricting means between its opposite ends, and means providing a flow path for said grit-free lubricating fluid from said reservoir means into the interface between said barrel and that portion of the exterior of said plunger in an area between said seal means encircling the opposite end portions thereof and whereby lubri cant escaping past said seal means is replenished with lubricant from said reservoir means.

ered into the well fluid.

3. The combination defined in claim 1 characterized in the provision of filter means in said reservoir between a fluid inlet at the lower end of the reservoir and the flow path for clean fluid passing to the exterior of said plunger.

4. The combination defined in claim 3 characterized in that said filter means comprises a filter cartridge located within and extending lengthwise of said reservoir means.

5. The combination defined in claim 4 characterized in that the upper end of said filter cartridge is imperforate and cooperates with the upper end of said reservoir means to provide a dead air chamber for trapping air to provide a resilient cushion effective to feed clean fluid from said reservoir means to the exterior of said plunger as the plunger is reciprocated.

6. The combination defined in claim 4 characterized in the provision of fluid seal means between the lower end of said filter cartridge and the juxtaposed interior surface of a component of said tubular plunger.

7. The combination defined in claim 4 characterized in that said filter cartridge is held detachably assembled to the interior of said plunger by a firm frictional fit between one end thereof and the juxtaposed surface of a component of said plunger.

8. The combination defined in claim 7 characterized in the provision of fluid seal means between the lower end of said filter cartridge and the juxtaposed interior surface of said reservoir means.

9. In a tubing pump as defined in claim 1 characterized in the provision of a filter cartridge supported in said reservoir means crosswise of fluid flow between a fluid entrance at the lower end of said tube and the end of said cartridge and the juxtaposed surface of one sidewall of said reservoir means.

11. The combination defined in claim 1 characterized in that said elongated tube is held detachably assembled to the interior of said plunger by a firm frictional fit between one end thereof and the juxtaposed surface of said plunger.

Claims

1. In a tubing pump for use in a well and of the type having a check valve-equipped tubular plunger having seal means encircling its opposite end portions and reciprocable axially of a tubular barrel for said plunger, that improvement for lubricating the interface between said plunger and said tubular housing with the fluid being pumped substantially free of grit and the like foreign matter which comprises: reservoir means for collecting and storing a continually replenished supply of clean oil from grit laden oil being pumped, said reservoir means including an elongated tube having its upper end secured in fluid-tight relation coaxially of and within the upper end portion of said plunger with the lower end portion in communication with a fluid flow passage interiorly of said plunger, said elongated tube cooperating with the interior sidewall of said plunger to form an annular reservoir for a quantity of trapped quiescent grit-free lubricating fluid from which grit gravitates back into the fluid being pumped and which quiescent-lubricating fluid is replenished as used from flow past the lower end of said elongated tube, means providing a main flow passage for conveying the fluid being pumped past the full height of said reservoir means which main flow passage is free of flow restricting means between iTs opposite ends, and means providing a flow path for said grit-free lubricating fluid from said reservoir means into the interface between said barrel and that portion of the exterior of said plunger in an area between said seal means encircling the opposite end portions thereof and whereby lubricant escaping past said seal means is replenished with lubricant from said reservoir means.

2. The combination defined in claim 1 characterized in the provision of means within the upper end of said reservoir for trapping air therein as said pump is lowered into the well fluid.

9. In a tubing pump as defined in claim 1 characterized in the provision of a filter cartridge supported in said reservoir means crosswise of fluid flow between a fluid entrance at the lower end of said tube and the means for passing fluid from said reservoir means to the interface between said plunger and the barrel of said tubing pump.

10. In a tubing pump as defined in claim 9 characterized in that said filter cartridge comprises a tubular member concentric to said elongated tube held assembled to the upper end of said reservoir means in a fluid tight manner, and a sealing gasket between the lower end of said cartridge and the juxtaposed surface of one sidewall of said reservoir means.