US2933042A - Additive well pump - Google Patents

Description

April 19, 1960 E. SCRIVNER ADDITIVE WELL PUMP led June 10, 1951 Wwww. ED/THZ Joe/mfg United States Patent C) ADDITIVE WELL PUMP Edith I. Scrivner, Lakewood, Calif.

Application June 10, 1957, Serial No. 664,567

3 Claims. (Cl. 103-1) This invention relates to well pumping equipment and more particularly to pumps used in producing oil wells.

In the use of well pumping equipment for the production of viscous crude oils, for example, the usual practice is to install means such as a reciprocating type of pump at a point below the fluid level in the well and operate the pump by an elongated member or sucker rod extending throughout the production tubing leading upwardly from the pump to the surface of the ground. At the upper end of the sucker rod a motor or engine is provided to impart a reciprocating motion to the sucker rod. The means for translating the motor rotation to the reciprocating rod is most generally a walking beam supported upon a suitable fulcrum and driven by a crank from the slow speedmotor.

In such an arrangement where the heavy oil surrounds the sucker rod throughout its length, the rate of travel of the rod is limitedsince its descent due to gravity is retarded by the effect of the heavy fluid. Accordingly, the capacity of the pump is reduced.

In addition, crude oil and other fluids pumped from the earth contain foreign matter and chemicals which have a deleterious effect on the production tubing and sucker rod. For example, encrustations and deposits are formed on the rod and the interior of the tubing which reduce the area through which the oil may flow upward.

For these and other reasons it is desirable in many pumping operations to introduce chemical additives to the crude oil or other fluid to increase the efiiciency of the pumping apparatus. That is, if heavy or viscous oil is being pumped it is advantageous to introduce a low viscosity fluid as a diluent which produces a condition which is more favorable to the eflicient pumping of viscuous oil from wells. In other instances it is desirable to introduce a chemical additive which prevents the accumulation of encrustations or deposits in the fluid passage from the well and around the sucker rod.

Accordingly, it is an object of the present invention to provide an improved well pump by which additive fluid may be introduced into the fluid being pumped in predetermined amounts.

It is another object of the present invention to provide an improved reciprocating well pump in which additive fluids are introduced only into the fluid which has entered the pumping apparatus.

It is a further object of the present invention to provide an improved well pumping apparatus in which the composition of the fluid flowing through the apparatus is accurately controlled.

It is another object of the present invention to provide an improved mixing pump for wells in which the additive fluid and the mixed well fluid are contained within the pumping apparatus.

The present invention is an improved well pump for mixing an additive fluid to the fluid being pumped and comprises a lower working barrel having an .additive fluid inlet thereto and an upper working barrel positioned above the lower barrel and. separated therefrom by a 2,933,042 Patented Apr. 19, 1960 mixing chamber. A first hollow plunger is reciprocable in the lower working barrel, and a second hollow plunger is reciprocable in the upper working barrel with the plungers being operably connected in a sucker rod string. A standing valve at the lower end of the lower working barrel allows entrance of additive fluid to the lower barrel which is pumped through the lower barrel to the mixing chamber by means of appropriate traveling valving. A second standing valve allows entrance of fluid from the well bore to the mixing chamber at the lower end of the upper working barrel. Traveling valve means on the upper plunger permit the mixed fluid to be pumped from the mixing chamber to the tubing string. The upper and lower plungers are of predetermined diameters depend ent upon the ratio of additive fluid to be mixed with the well fluid.

The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only, and is not intended as a definition of the limits of the invention.

Figure 1 is a partially sectional view in elevation of the presently preferred embodiment of this invention disposed within a well casing;

Figure 2 is a view in cross-section of the pump of the present invention;

Figure 3 is a view taken along line 3-3 of Figure 2; and

Figure 4 is a view taken along line 44 of Figure 2.

Referring now to the drawing, the well casing 11 is supported at its upper end by a pumping head of any preferred form. Branch pipes extending from the casing serve to convey any gas that the well may be producing while the oil or fluid being pumped flows upward through the production tubing 12 and is discharged through a discharge pipe. A polish rod passes through a stufling box at the top of the pumping head and is connected to the sucker rod 14. The pumping and discharge arrangement and apparatus are not shown or described in detail since they may be of any type known to the prior art and form no part of the present invention.

As shown in Figs. 1 and 2, the mixing pump of the present invention comprises an upper pump section 15 and a lower pump section 16 which are interconnected and adapted to be lowered into the well casing 11 containing a fluid, such as oil, which is to be pumped to the surface. The upper pump section 15 comprises a barrel 17 which is connected at its upper end which is the outlet end of the pump section to the lower open end 27 of the production tubing 12 through which the oil is pumped to the surface. The drawing is partially schematic and various unions and connections and standard pump parts of a type well known to the art may be used throughout the present invention. In the illustrative embodiment, the upper pump barrel 17 is connected to the inlet end 27 of the tubing -12 by means of a connecting collar 19 which is female threaded and mateable with the male threads of the tubing 12, and male threaded at its lower end to be mateable with female threads at the upper end of the barrel. Thus, the barrel 17 is removably connected to the tubing. An upper pump plunger 20 is tubular in configuration and has an outside diameter substantially equal to but less than the inside diameter of the barrel 17 with a longitudinal opening 18 therethrough. The upper end of the plunger 20 is aflixed to the sucker rod 14 through a traveling valve '21 of the type well'known to the art which allows the passage of fluid upward through the plunger 20 and valve 21, but prevents the flow of [fluid downward and into the plunger. In the embodiment shown the traveling valve 21 comprises a seat 22 having an opening 23 therethrough which is threadably mateable with the plunger 20. The valve cage 24 is in turn threaded upon the seat and encloses a ball check 25 which is mateable with the seat 22 to close the opening 23 when fluid attempts to flow downward therethrough. The ball 25 is free within the cage 24 and openings 26 are provided in the cage to allow passage of fluid when the upward flow of fluid lifts the ball 25 from its seat 22. The cage 24 is threadably connected to the lower end of the sucker rod 14, thus affixing the upper plunger 20 to the sucker rod for vertical reciprocating movement therewith within the upper barrel. As is well known in the art the volume of fluid pumped by the upper plunger is substantially equal to the internal cross-sectional area of the barrel times the length of stroke as will be further described in connection with the operation of the apparatus in its presently preferred form.

At the lower end 62 of the upper barrel 17, which forms the fluid inlet of the upper pump section 15, a mixing chamber 29 is defined by the interior of a vertically disposed housing formed by a tubular section 30 of predetermined length. The chamber tubing 30 is threadably connected to the lower end of the upper barrel 17 and is decreased in diameter at its lower end. At the lower end of the chamber tubing 30 a lower pump barrel 33 is connected at the upper end 35 thereof by a connecting collar 34 which is mateable with male threads on the chamber tubing 30 and female threads on the lower barrel 33, as previously described. A protrusion 36 is provided at one side of the chamber tubing 30 to define a slip joint 37, of the type known to the art, into which a fluid conduit 38 may be slidably engaged. That is, the protrusion defines a cylinder having an inside diameter substantially equal to the outside diameter of the fluid conduit and forming a fluid inlet 43 through a standing valve 40 into the mixing chamber 29. The standing valve is of the type well known to the art having a ball check 41 contained Within a cage 42 and mateable with the fluid inlet 43 to allow the passage of fluid from the conduit 38 into the mixing chamber but to prevent flow of fluid outward from the chamber.

As described hereinbefore the lower barrel 33 is affixed at the lower end of the chamber tubing 30 such that the upper end 35, which is the outlet end of the lower pump section 16, is in fluid communication with the mixing chamber 19. The lower barrel 33 is of substantially lesser inside diameter than the upper barrel 17. A lower pump plunger 45 of the type well known to the art is provided for reciprocating movement within the lower barrel and is again tubular in configuration with an outside diameter substantially equal to the inside diameter of the barrel 33. The upper plunger 20 and the lower plunger 45 are interconnected by a connecting rod 46 which is connected to the upper plunger 20 at the lower end thereof through a spider 47 or similar connecting means which allows the passage of fluid into the opening 18 of the plunger. The connecting rod is connected to the lower pump plunger 45 at the upper end thereof through a traveling valve of the type well known to the art and similar to that described at the upper end of the upper plunger. That is, a ball check 48 is contained within a cage 49 which is threadably connected to the connecting rod 46. The ball 48 is above the seat 50 which is affixed to the plunger 45 and is mateable therewith to allow the upward passage of fluid through the lower plunger 45 but to prevent downward travel of fluid from the mixing chamber 29 into the plunger opening 51.

Thus, the pump plungers 20 and 45 are connected to form a continuous plunger structure and are separated by a mixing chamber from which fluid can flow only upward through the upper plunger. As discussed hereinbefore, the plungers and respective barrels are of different diameters and will pump proportionally different volumes of fluid as described in further detail following.

A length of tubing or sleeve 53 is connected at the lower, or inlet, end 61 of the lower barrel to form an extension thereof and has an additive fluid inlet 54 therein to which an additive fluid conduit 55 is connected by standard fittings or joints. Thus, as shown in Figs. 1 through 4, the additive fluid conduit is connected beneath the lower barrel and extends upward alongside the pump and tubing 12 within the casing to the surface where a source S (shown diagrammatically in Figure 1) of fluid to be added to the oil or well fluid is supplied. A slip joint of the conventional type may be inserted into the fluid conduit for ease of assembly or removal. An hydraulic pump P may be used at the surface in some applications to furnish suflicieut pressure to the additive fluid for circulation although gravity pressure will be suflicient for most purposes. Interposed between the additive 'fluid inlet 54 and the lower barrel 33 is a standing valve 56 of the conventional type described hereinbefore to allow the passage of additive fluid upward into the lower barrel and plunger but to prevent flow of fluid from the lower barrel. A closure 57, such as a pipe blank, is positioned in the sleeve 53 beneath the additive fluid inlet to prevent flow of fluid downward from the inlet 54.

A length of perforated pipe 59 is aflixed beneath the closure 57 having a connection for the oil conduit 38 to permit oil or other fluid being pumped to flow from the well through a fluid inlet 43 and the standing valve 40 and into the mixing chamber. Accordingly, oil from the well is admitted to the mixing chamber 29 through the standing valve 40 while additive fluid is supplied from the surface and is admitted through the second standing valve 56 and pumped into the mixing chamber 29 by the lower pump in quantities determined by the diameter of the lower pump barrel.

Thus, in operation, referring to the figures the fluid to be added to the oil being pumped, is supplied from a tank or reservoir (not shown) and flows downward through the conduit 55 to the lower standing valve 56. On the downward stroke of the plungers, additive fluid passes upward through the traveling valve 48 of the lower plunger. Simultaneously, oil is admitted through the open pipe 59 and passes through the conduit 38, upward through the standing valve 40 and into the mixing chamber 29. As the plungers move upward the traveling valve 48 on the lower plunger seats, and the additive fluid in the barrel 33 above the plunger is moved into the mixing chamber 29. The volume of additive fluid pumped into the chamber is thus equal to the cross-sectional area of the lower plunger times the length of stroke. The additive fluid and oil admitted to the chamber through the standing valve are mixed in the chamber and then pumped upward by the upper plunger. Thus, on the downward stroke of the plungers the upper plunger traveling valve 21 opens and the mixed fluids within the chamber flow through the traveling valve 21 to the top of the plunger 20. On the upward stroke, the valve 21 seats and a volume of mixed fluids substantially equal to the cross-sectional area of the upper plunger times the length of stroke is moved upward through the production tubing 12. From the foregoing it may be seen that the proportion of additive fluid or diluent to be mixed with the oil being pumped through the tubing can be predetermined and closely controlled by selection of the correct diameter of the lower plunger and barrel. That is, for example, if a three to one ratio of oil to additive fluid is required such a ratio is obtained by utilizing a lower plunger and barrel having a crosssectional area equal to one-third the cross-sectional area of the upper plunger and barrel.

Although the present invention has been described in connection with a traveling plunger type of pump it is equally applicable to a pump of the traveling barrel type and various modifications in the standard pump parts and fitting can be made. Thus, the present invention provides an improved additive or mixing pump which allows a predetermined proportion of additive fluid to be mixed in a closed cycle with the oil or other fluid being pumped through the production tubing, but which does not allow contamination of the fluid in the well itself, nor the loss of additive fluid to surrounding areas.

What is claimed is:

1. An improved well pump for mixing an additive' liquid to the well liquid being pumped through production tubing having a liquid inlet at the lower open end thereof substantially vertically disposed in a well comprising: an upper liquid pump vertically disposed below said tubing, said upper pump having a liquid outlet connected to and communicating with the liquid inlet to said production tubing; a tubular section defining a liquid mixing chamber vertically disposed below said upper liquid pump, said tubular section being connected to and in liquid communication with the liquid inlet to said upper pump; a lower liquid pump vertically disposed below said tubular section, said lower pump having a liquid outlet connected to and in liquid communication with said tubular section; an additive liquid inlet to said lower pump, closed conduit means between said liquid inlet to said lower pump and a source of additive liquid at the surface of the well; a well liquid inlet to said mixing chamber; means operatively interconnecting said up per liquid pump and said lower liquid pump such that the pumping capacity of said lower pump is substantially less than the pumping capacity of said upper pump, whereby said lower pump pumps additive liquid to said mixing chamber and said upper pump pumps additive liquid and well liquid to said production tubing and from said well.

2. An improved well pump for mixing an additive liquid to the well liquid being pumped through production tubing having a liquid inlet at the lower open end thereof substantially vertically disposed in a well comprising: an upper pump barrel having a first predetermined inside diameter, a lower pump barrel having a second inside diameter substantially less than said first diameter and a closed lower end, said upper and lower pump barrels being vertically disposed and spaced apart by a tubular section defining a mixing chamber, said tubular section being connected to the lower end of said upper barrel and the upper end of said lower barrel to define a liquid path from the liquid outlet of said lower barrel to the liquid inlet of said upper barrel, said upper barrel being connected at the upper end thereof to the open end of said production tubing; said tubular section defining a well liquid inlet to said mixing chamber; an additive liquid inlet to said lower barrel proximate the closed lower end thereof, closed conduit means from a source of additive liquid at the surface of said well to said additive liquid inlet; an upper pump plunger for pumping mixed well liquid and additive liquid reciprocable with respect to said upper barrel, a lower pump plunger for pumping additive liquid reciprocable with respect to said lower barrel, said upper and lower pump plungers having pumping diameters proportional to said first and second diameters respectively, said upper and lower plungers being operably interconnected by a connecting rod connected vertically therebetween, said upper pump plunger being connected to a sucker rod for reciprocation therewith; and valving means to allow the flow of additive liquid upward through said lower barrel to said mixing chamber and to allow the flow of additive liquid and well liquid through said upper barrel to said production tubing and from the well.

3. An improved well pump for mixing an additive liquid to the well liquid being pumped upward through production tubing in a well comprising: an upper and lower pump section substantially vertically disposed in said well, said upper pump section including an upper tubular barrel having a first inside diameter, said upper barrel connected at the upper end thereof to the lower open end of said production tubing; a vertically disposed tubular section, the interior surface of which defines a mixing chamber, said tubular section being connected at the upper end thereof to the lower end of said upper barrel in communication therewith; said lower pump section including a lower barrel having a second inside diameter substantially less than the inside diameter of said upper barrel, said lower barrel being connected at the upper end thereof to the lower end of said tubular section and communicating with said mixing chamber, said lower barrel having a closed lower end; a vertically disposed upper traveling plunger reciprocable within said upper barrel; a vertically disposed lower traveling plunger reciprocable within said lower barrel, said lower plunger being of substantially lesser diameter than said upper plunger; a connecting rod operatively interconnecting the lower end of said upper plunger and the upper end of said lower plunger; said upper plunger being connected at the upper end thereof to a sucker rod for reciprocation therewith; an upper traveling valve on said upper plunger to allow upward travel of liquid from said upper pump section to said production tubing; a lower traveling valve on said lower plunger to allow upward flow of liquid from said lower pump section to said mixing chamber; a first standing valve proximate the closed lower end of said lower barrel to allow upward flow of liquid to said lower barrel; an additive liquid inlet to said lower barrel between the closed lower end thereof and said first standing valve; closed conduit means connected between said additive liquid inlet and a source of additive liquid at the surface of said well; a well liquid inlet to said mixing chamber, and a second standing valve at said well liquid inlet whereby said lower pump pumps additive liquid to said mixing chamber and said upper pump pumps additive liquid and well liquid to said production tubing and from said well.

References Cited in the file of this patent UNITED STATES PATENTS 955,580 Caverno Apr. 19, 1910 966,772 Sattler Aug. 9, 1910 1,104,962 Clark July 28, 1914 1,322,236 Fish Nov. 18, 1919 1,421,004 Hibbard June 27, 1922 1,597,161 Kellogg et a1. Aug. 24, 1926 1,703,423 Herman Feb. 26, 1929 1,703,428 Neilsen Feb. 26, 1929 1,738,136 Bannon Dec. 3, 1929 1,771,070 Bannon July 22, 1930 2,029,473 Fox Feb. 4, 1936 2,213,807 Starbuck Sept. 3, 1940 2,330,781 Langmyhr et al Sept. 28, 1943 2,473,726 Payne June 21, 1949 2,567,513 Haines Sept. 11, 1951 2,764,940 Long Oct. 2, 1956

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