CA2278827A1

CA2278827A1 - Single string reciprocating pump system

Info

Publication number: CA2278827A1
Application number: CA002278827A
Authority: CA
Inventors: Jianshe James Wang
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-07-23
Filing date: 1999-07-23
Publication date: 2001-01-23

Abstract

A hollow sucker rod pumping system permits the production of fluid within the hollow rod string. The system is adapted to include a rigid wellhead which allows access to the casing annular space, one-trip running and setting of a pump with the hollow rod string. Preferably, means to heat the rod string electrically may be provided.

Description

U.S. PROVISIONAL PATENT
Docket No. 12386-001 ETY
SINGLE STRING RECIPROCATING PUMP SYSTEM
FIELD OF THE INVENTION
The present invention relates to a single string pumping system to produce underground fluids and crude oil in particular. In this invention, a single hollow rod tube is provided in place of a conventional solid sucker rod and tubing structure where the oil is produced in the annular space between the rod and the tubing.
BACKGROUND OF THE INVENTION
Sucker rod pumping is widely used in the production of underground fluids such as crude oil and water. In a conventional sucker rod pumping system, a downhole barrel/plunger pump is driven by a surface walking beam pump jack. An oil well is usually lined with a well casing and also includes a tubing string and a solid sucker rod string which reciprocates the pump plunger vertically within a pump barrel. The pump barrel is secured to the end of the tubing. The crude oil is pumped to the well head through the annular space between the rod and tubing. In this system, the tubing cost can be a significant portion of the total capital cost, especially in deep well installations.
Conventional pumping systems of this type suffer from low efficiency. Pump efficiency averages less than 50% due to elasticity in the tubing length which occurs when switching between the up and down strokes. Frequent pump servicing is usually required to remove paraffin wax deposition from the tubing or sand which has settled on top of the barrel and plunger. When the rod pump is used in a heavy oil well, rod falling difficulties during the down stroke are usually encountered due to the high density of the crude oil and high viscous friction W:\ETYFILES\Wang,J\Jame-Ted ju121.doc between the sucker rod and the crude oil. Furthermore, a large amount of energy is utilized in the pumping action in just lifting the rod string due to the weight of the rod string and due to friction between the sucker rod and the crude oil.
Another significant disadvantage of conventional tubing/sucker rod configurations is encountered when servicing the pump. In order to pull the pump out of the hole, two separate trips are required to pull the tubing string and the rod string out of the hole.
It is known to use hollow sucker rods in place of conventional solid rods, however, the hollow bore of the rod is typically used to deliver liquid downhole from the surface. In U. S.
Patent No. 4,089,626, hollow rods are used to inject fluid into the bottom of the pump. No suggestion is made that fluid may be produced through the hollow rod.
Therefore, the tubing string has not been eliminated in this patent. In U.S. Patent No. 4,984,003, a crude sample recovery method is provided which uses the hollow rod center for injecting chemicals such as surfactants which may help the flow of viscous fluids. However, a conventional rod/tubing structure is also used in this patent.
In Chinese Patent No. 95-104622.5, a hollow rod oil production system is disclosed. A single rod string substitutes for the rod/tubing concentric structure. In one example, the well head uses flexible hose as the oil outlet port. This arrangement automatically increases safety and environmental concerns, due to the possible high pressure, repeated bending, and severe ambient conditions which may cause the flexible hose to deteriorate and fail. In the other example, a rigid well head is disclosed, however, the casing annular opening is blocked, restricting any access from the outside. This is not acceptable because the casing vent is necessary for many essential well service operations, such as reversed well wash circulation, releasing casing gas, injection of lifting gas and dynamic fluid level measuring. As well, this invention requires two separate trips to set the dual slip packer and pump/piston in position, as is the case with other conventional pump systems.

It is also known to use electric heating to prevent solid formation in crude oil producing wells and to reduce viscosity of the crude oil. An electrically heated sucker rod was disclosed in U.S. Patent No. 3,859,503, which has electric resistance heating elements installed in each rod joint. The heating element is electrically insulated in the bore hole. This type of arrangement of heating element in series will restrict the practical running depth (and effective working length) due to the voltage gradient drop. On the other hand, if an elevated voltage is used to try to solve the voltage drop, the electric insulation becomes difficult. The hydraulic sealing and electric insulation of the rod system escalates the cost of manufacture.
In U.S. Patent No. 4,716,960, various means for introducing electric current into the well were disclosed. The tubing can be heated by passing electric current to it using different means.
The system is still uses the concentric rod/tubing structure when a rod pump is used (annular space is used for the flow avenue), therefore all drawbacks of the rod /
tubing structure remain in the system. Furthermore, in the rod pump case, electric insulated conduction is accomplished through a fiberglass rod, then by silver soldering welded to the metal rod and finally through a wheeled connection to the tubing, a complicated and high-cost system. Sand deposition will be even more severe in such a system because the density and viscosity of the oil in the annular space is reduced, even though the velocity and cross sectioned area remain unchanged.
In Chinese Patent 9216143.7, an electrically heated rod is disclosed in which the electric cable is placed in the center of the hollow rod. The hollow center of the rod is sealed from the underground fluid. The concentric rod/tubing structure is still the basic structure in this patent.
The above arrangement, the same as in most of the plunger/rod pumping systems, must use the annular space between the tubing and the hollow rod as its fluid delivering channel.
Therefore, there is a need in the art for a pumping system which may mitigate the disadvantages of the prior art and allow for:
(a) reduction of the well completion costs due to the elimination of the tubing string;

(b) higher pump efficiency due to the elimination of the elastic elongation of the tubing string which occurs during reciprocation of the rod string; and due to the elimination of the fluid friction resistance during the up stroke;
(c) reduction of the rod string elastic elongation because of a thinner, lighter fluid column and the higher rigidity of the larger cross-section;
(d) reduction in solids accumulation due to the higher fluid velocity in a smaller cross-section;
(e) less heat loss from the fluid to the surroundings which will move wax precipitation point upward;
(f) reduction of the work-over time and labor effort due to saving one trip of tubing pulling/running;
(g) mitigation of rod falling difficulties as a result of reduced friction resulting from the temperature/viscosity effect;
(h) the ability to install the apparatus in slim holes or deformed holes due to the smaller size that can be used; and (i) use of a rigid well head instead of a flexible hose while maintaining an open casing annular vent.

SUMMARY OF THE INVENTION
The present invention is directed to a novel hollow sucker rod pumping system which allows for production of fluid within the hollow rod string, a rigid wellhead which allows access to the casing annular space, one-trip running and setting of the pump with the hollow rod string and optionally, electric heating of the rod string using Kelvin's skin effect and the proximity effect.
Additional advantages may be realized as follow. Due to the smaller cross-sectional area of the hollow rod as compared to the annular space in a conventional tubing system, a higher fluid flow velocity is maintained which provides a higher solid carrying capacity. Also, there will be less heat loss of the underground fluid to the surrounding formation, and therefore wax precipitation is likely to be reduced. The tubing string becomes unnecessary.
One work-over trip is saved because the pump may be run into the hole in the trip and retrieved in one trip. Load on the walking beam of the surface pump jack is reduced because a thinner liquid column is lifted. In addition, the load on the pump jack during the up stroke is reduced because the fluid viscous friction is removed. The fluid column is lifted together with the hollow rod, therefore there is no relative fluid moving to relative to the wall of the rod tube, which is unavoidable in the rod/tubing pumping system. Another advantage of the system is the fact that the liquid column simply "stays in" the rod tube all the time thereby eliminating the hydrostatic pressure against the plunger/barrel gap. The benefits obtained from heating the string include lower oil viscosity which improves the pump efficiency. Heating the invented string is optional and may be an alternative measure for the heavy oil or high wax well case. This pump system may be designed for a deformed casing well where normal tubing and pump size are restricted, or for use in a slim hole.

BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of an exemplary embodiment with reference to the accompanying simplified, diagrammatic, not-to-scale drawings.
In the drawings:
Figure 1 is a schematic representation of the pumping system of the present invention.
Figure 2 is a cross-sectional detail view of a preferred embodiment of a wellhead of the present invention.
Figure 3 is a cross-sectional view of a preferred embodiment of the cross-over joint.
Figure 4 is a view of the pump barrel, pump barrel slip, pump barrel hunger and barrel retrieval / actuation.
Figure 5 is a schematic view of the of the spread J slot /pin and S slot/pin.
Figure 6 is a view of the shear pin window nipple and drop bar.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for a novel hollow sucker rod pumping system.
All terms not defined herein have their common art-recognized meanings. As used herein, the term "single string" or "hollow rod string" or "rod string" refers to a hollow sucker rod string which drives the down hole plunger reciprocally and delivers the produced fluid through its central bore. As used herein, the term "stationary string" refers to the joints and pump barrel which engage the well casing and remain stationary while the pump plunger or piston is reciprocated by the single string.
In general terms, as shown schematically in Figure 1, the pumping system of the present invention combines a rigid well head (5) having a casing vent (7), a hollow rod string ( 11 ) and stationary string (60). The combination of the hollow rod string and the stationary string allows for the running in and retrieval of the pump barrel in one trip. The tubing string is eliminated as the fluid is produced within the hollow rod string (11). The hollow rod (11) may be electrically heated as an option for heavy oil application or for wells with a high wax presence.
A. The Electric System Referring now to Fig 1, a transformer ( 1 ) converts the source power into the desired single phase AC, for instance to 440V, 60 HZ AC power. The power is then transferred to the control panel (2). An electric conduit (3) which can be flexibly hung on the walking beam of the surface jack pump (not shown) by ordinary means, is introduced into the rod conduit joint (4).
The conduit (3) is then introduced into the hollow polished rod (23) and passed through the rod cross-over joint (21), and goes out of the cross-over joint (21) from the lower end through a port (35) as shown in Fig. 3. The electric conduit (3) is then secured by any suitable means (9) such as a clamp to the outside surface of the hollow rod (11). The conduit (3) is electrically connected to the hollow rod (11) at a pre-selected depth (sufficient for the depth of the solid formation) by a suitable conducting connector (12). The well head (5) is grounded (8), as is the power unit.
Therefore the electric current circuit is completed.
There is enough of a gap between the conduit clamp (9) and the separating sleeve (10) to avoid substantial contact and friction wear since the hollow rod (11), together with the clamp (9) and conduit (3), are moving up and down within the separating sleeve (10). Conduit (3) is also electrically insulated and designed for the working environment of downhole conditions. For example, the maximum temperature limit of the conduit should preferably not be less than 150° C. Once suitable AC electric current is applied to the system, heat will be generated by the hollow rod (11). The heat is generated by Kelvin's skin effect which is the phenomenon of current only traveling on the inner surface of the tube, which leaves only a low voltage on the outer surface of the rod tube. A test indicated that under AC
voltage of 390 V and a current of 120 A, the outer surface of the hollow rod only carries 0.09 V
for a 9 meter joint and about 9 V for an 800 meter connected string. The voltage at the wellhead at the surface will be zero because of the energy consumption through the rod (the voltage gradient being towards the wellhead) and because the wellhead is grounded. The system is therefore electrically safe.
In another embodiment of the electrical heating system the conduit (3) may be placed inside of the tube rod (not shown). Due to the concentric configuration, proximity effect may increase the apparent electric resistance of the tube rod therefore make the generation of heating faster and to a higher temperature level. In this embodiment, a means of centralizing the conduit may be required to ensure that the conduit is in the center of the tube rod. The centralizing means should also have fluid passing openings to allow the fluid to flow through them.
B. The Heating System The conduit (3) functions only as the AC current transporting medium. There is no heating element except the hollow rod associated with the system. Heat on the hollow rod is generated through Kelvin's skin effect and through the proximity effect which is the phenomenon of apparent resistance increase in the turns of a coil type conductor when high frequency AC current is applied. The increased apparent resistance of the hollow rod is a major contributor to heat generation.
The temperature of the rod may be controlled through a feed back system. In a preferred embodiment, a temperature sensor (not shown) may be installed within the wellhead (5) to provide a feed back signal to a controlling system in the control panel (2). The feedback _g_ signal may start or shut down the power supply at a pre-designated temperature range or may adjust the power output level to maintain the oil flow from the oil outlet port (6) at a desired temperature. The crude oil clouding point or wax/paraffin solidification point is typically in the range of 20 to 70° C. At temperatures less than 100° C, most carbon metal mechanical properties, such as minimum yield stress, strain or elastic Young's modulus, are not meaningfully affected from a practical engineering standpoint. The hollow rod is constructed of an industry accepted material such as 35CrMo or API N80 steel. Therefore, elevated temperatures at the 100° C level will not raise any practical concerns for the mechanical performance of the rod while still being above the wax solidification point.
C. The Well Head, Separating Sleeve & Cross-over Joint Referring to Fig. 1, a section of a conventional solid rod (22) is connected at its upper end to the walking beam of the surface pump jack (not shown). The rod connector (4) has a hollow center (4a) and a side port (4b) is connected to the lower end of the solid rod (22). The hollow polished rod (23) is connected to the rod connector (4) and forms an open avenue for the placement of conduit (3). Conduit wire seals (37) are provided at the lower end of the polished hollow rod (23) to prevent any fluid from entering the hollow center, which is shown in Fig. 3.
As shown in Fig. 1 and Fig.3, the cross-over joint (21) has a hollow chamber and several open slots (33) in its top cone-shaped section which allow the fluid to flow from the hollow rod center into the oil outlet port (6) as indicated by Fig. 1 and 2. The cross-over joint (21) has a larger diameter sliding piston section which matches the inner diameter of the separating sleeve (10) so that no fluid above may leak back to the well. The separating sleeve (10) is designed with sufficient length, i.e. the same length as the piston stroke in the pump barrel, to enable the cross-over joint (21) to travel up and down within the sleeve (10). Both surfaces of the cross-over joint (21) and the separating sleeve (10) are treated to withstand constant friction wear over long periods, as is well-known in the art. With this piston and barrel mechanism, the fluid produced from the hollow rod (11) can be delivered to the outlet port (6) exclusively.

Referring to Fig. 3, the polished rod (23) is connected to the cross-over joint (21). An open port (32) is arranged at the top of the joint (21 ) with seals (37) at both end of port (32). The electric conduit (3) runs through the port of the polished rod (23) and then through the chamber of the cross-over joint (21), through the seals (37). Therefore no fluid is allowed to enter the polished hollow rod (23). At the lower end of the cross-over joint (21), the conduit wire (3) passes through the port (35) which has connectors (34) and (36) to secure the wire in place. The cross-over joint (21) preferably has four ports or slots (33) evenly distributed around the cone shaped shoulder section on its upper part, which are the flowing channels for fluid to flow from the hollow rod center into the well head outlet port (6) and then to the outside of the well. The cross-over joint (21 ) also has a larger diameter body below the cone shaped shoulder section that leaves a gap above the cross-over joint (21) and the separating sleeve (10) as a fluid flowing channel. The inner diameter of the separating sleeve (10) matches with the outer diameter of the cross-over joint (21) in such a manner that the cross-over joint slides within the sleeve (10) in a fluid-tight manner.
As shown in Fig. 2, the separating sleeve (10) connects with a cone shaped hanger (27) which is sealed to the casing joint (29). The sleeve hanger (27) also has a seal ring (26) which matches the oil outlet joint (25) and "O" ring seal (28) which matches with casing joint (29). The seal ring (26) is made of a softer metal than the sleeve hanger (27) and the outlet joint (25), such that when compression stress is applied by bolting the outlet joint (25) to the casing joint (29), the seal ring (26) will act as a metal seal. The seal ring (26) should preferably be replaced each time the well head is disassembled. The outside diameter ("OD") of the separating sleeve (10) is designed of such size as to leave a gap between itself and the inner diameter ("ID") of the casing joint (29). For instance, in the case of 5" casing (19) with wall thickness of 10.36mm and ID of 106.3 mm, the OD of the separating sleeve can be designed the same as that of API standard 2.875" tubing which has an OD of 73.025 mm, and ID of 57.4mm. That will give a gap between the separating sleeve (10) and the casing (19) of 16.64 mm. The above gap arrangement is large enough for normal casing vent operation. A larger gap can be arranged by adopting a larger ID

casing joint if desired. In the above example, the separating sleeve (10) has a ID of 57.4 mm, and the cross over joint may be designed with ID of 40 mm which has a larger flowing area than the main string. That will give more than 8.5 mm a wall thickness of the cross over joint, which will satisfies the mechanical strength requirement with the opening port on it. In the above example, an OD of less than 40 mm hollow rod is then allow to be connected with the lower end of cross over joint (21) through commonly known means.
As shown by Fig. 3, the cross-over joint (21) has a port (35) leading the conduit (3 ) from the chamber of the cross-over joint (21) to the outside of the cross-over joint (21), and the conduit is then clamped to the outer surface of the hollow rod (11 ) by means of the clamp (9). At both ends of the port (35), the wire passes through seals (34) and (36). This arrangement satisfies the need for introducing the conduit (3) to the desired depth of the hollow rod from the outside without interrupting the sliding seal between the crossover joint (21) and the separating sleeve (10). The clamp (9) is designed in such a way that the outer maximum diameter is smaller than the OD of the cross-over joint 21 in order to avoid any possible contact with the separating sleeve (10).
D. The Single String and the Stationary String Figure 1 schematically illustrates the stationary string (60) after it has been run into the hole and set to engage the casing (19). When running into and out of the hole, the stationary string (60) engages and is locked to the hollow rod string ( 11 ). Once in position, the hollow rod string disengages the stationary string and may reciprocate to produce the pumping action.
As shown in Fig 4, a hanger setting/flshing pin or a "J" pin (13) is secured on the exterior of the hollow rod string (11). A pump plunger or piston (38) is secured to the lower end of the hollow rod string (11). The pump piston (38) has a hollow chamber and includes a traveling valve ( 17) at its lower end.
The stationary string comprises, in order from top to bottom, a "J" slot joint (20), a "S" slot joint (39), a slip joint (41) and a pump barrel (16). These parts are shown in partly disassembled form in Fig. 4. The "J" slot joint (20) has a J type slot (20a) for the receiving the J pin (13). The S slot joint is secured to the bottom of the J slot joint (20) and has a S
slot for receiving the S pin (40) which is secured to the slip joint (41). The S slot joint (39) slidingly engages the slip joint (41) and includes a slip engaging cone (42) which activates the slips (43) on the slip joint (41).
The cone (42) is rotatably mounted to the S slot joint. This arrangement allows the cone to be pushed in or pulled out from the slips (43) without taking any rotation torque during the releasing operation of the slip. A set of slips (43) through high elastic steel belts (44a) are secured to the slip joint (41) at a suitable position. The home position of the slips is a position that the slips are not engaged as shown in Fig. 4.
A set of friction belts (15) are secured to the slip joint (41) around the circumference of the slip joint. The friction belts are designed and assembled in such a way to create frictional resistance to either vertical or rotational movement. However, the level of resistance is not so high that manipulating the hollow rod string or stationary string is difficult. The friction belts also serve to centralize the stationary string within the well bore. The pump barrel (16) is then connected to bottom of the slip joint. There is a stationing check valve (18) secured to the bottom of the pump barrel and a gas relief pin (49) and mounting bracket (50) is also provided. An anti-wear seal sleeve (45) receives the pump plunger (38) within the pump barrel.
The method of running the string into and out of the hole will now be explained with reference to Fig. 5. Which shows the spread view of the J slot joint (20) and The S slot joint (39).
Shadowed dot point shown on the view indicating the initial running in hole position of the J pin and the S pins of the assembled string.
1. During the running-in-hole trip, the stationary string is in the position depicted in Fig 4 and Fig 5. The J pin (13) is in position "a" of the J slot (20a) while the S
pin (40) is in position "d" in the S slot (39a) as the hollow rod string (11)/stationary string (60) combination is lowered to the desired depth. The J pin pushes downward on the stationary string which is slightly resisted by the frictional resistance provided by the friction belts (15). The "d" position of S pin locks the slip in a home position to prevent any vertical movement of the cone (42). The string may be moved vertically and rotated counter-clockwise without the risk of pre-setting the slips.
2. To release the slip from its home or travelling position when the pump barrel is at the desired depth, the hollow rod string is first rotated clockwise. Rotation of the hollow rod string obviously rotates the J pin, thereby moving the J slot joint. As a result, the S slot joint rotates relative to the S pin, which remains stationary because of the friction belts on the slip joint. The S pin will then occupy position "e". The J pin remains at position "a".
This unlocks the slip joint from the S slot joint. Next, the hollow rod string (11) is slacked and lowered down. With the friction resistance from bottom, the J pin will remain in position "a" while the S pin will then be moved to upward in the S slot to position "~'.
This action will push the slip cone (42) downward to the engaged position where the cone causes the slips to bulge outward and engage the casing wall.
3. The hollow rod string is then rotated clockwise again in order to lock the slips in the engaged position. Clockwise rotation will move the S slot joint such that the S pin now occupies position "g". The J pin (13) still remains in the position "a".
4. The hollow rod string must now be disconnected from the stationary string by releasing the J pin from the J slot. This is accomplished by pulling upward and rotated clockwise at the same time. While the S pin remains in "g" locking position, the J pin will be pulled and moved out of the J slot through channel "c". The J pin (13) needs to be pulled to a pre-designed distance away from the J slot for safety and practical reason.
This pre-designed distance is the same safety gap distance from the bottom of the traveling valve (17) to the top of the stationing valve (18). The polished rod (23) and the solid penny rod (22) shown in Fig. 1, at the surface is then connected to the horse head of the pump jack beam (not shown). During this connection, both the surface horse head (not shown) and the downhole pump piston are maintained at their bottommost position. The pump and string are all prepared for pumping operation.

During the down stroke of the hollow rod string during normal pumping, stationary valve (18) is forced to close, the traveling valve (17) opens and fluid in the pump barrel (16) is squeezed into the piston chamber (38). During the upstroke, the traveling valve (17) closes so that the fluid column remains within the hollow rod string and is lifted upwards.
The operation of retrieve the pump barrel is just the opposite of the setting operation as described above. The string (11) is first lowered and the J pin (13) is then caught by the J slot (20) and placed in the position of "a". Rotating the string (11) from surface counter-clockwise will release the S pin from locking position "g" to "f'. Pulling the string (11) will pull the slip cone (42) out of the slips and the slips will move back to the home position by the force of the elastic belt shape steel plate (44a). Rotating the string (11) further counter clockwise will then lock the slips in the home position again. The string is then pulled straight upward. The J pin moves to position "b" and pulls the stationary string out of the hole.
In oil wells with a high gas content, the pump may sometimes suffer from gas lock in the pump barrel. This problem may be alleviated by adapting a commercially available gas-releasing pin (49) to the top of the stationary valve (18), as is well known in the art.
It is also desirable to provide a shear pin window nipple within the hollow rod string as is shown in Fig. 6 to release the fluid column within the hollow rod string when pulling the string out of the hole. A drop bar (49) is released in the bore of the hollow rod string which reaches the window nipple and shears the pin (48). This opens window nipple windows (46a) to permit fluid to drain out as the string is being pulled out of the hole.
The above mechanism allows the hollow rod string to work as flowing channel and deliver reciprocal driven force to the pump plunger at the same time. Another important function of the above mechanism is the pump barrel slip anchors may be run into the hole with the hollow rod string, set and locked in the working position, and then be later retrieved by the same hollow rod string with only one trip.

Claims

1. A well head for use with single heated hollow rod string reciprocating pump system in an oil or underground water well having a well casing, said well head comprising:
(a) a well head body defining an internal bore for receiving a polished rod, an oil outlet port and a casing outlet port;
(b) a separating sleeve suspended within the well head body internal bore;
(c) a cross-over joint having a top end which engages the polished rod, a bottom end which engages the hollow sucker rod and which is positioned within the separating sleeve, said cross-over joint defining an internal bore which is in fluid communication with the hollow sucker rod, the well head body internal bore and the oil outlet port; and (d) a heating wire which passes through the polished rod, through the internal bore of the cross-over joint, through the cross-over joint itself to an exterior surface of the hollow sucker rod.

2. The well head of claim 1 wherein the well head body internal bore defines a sloped shoulder and the separating sleeve is suspended from the sloped shoulder by means of a cone-shaped hanger.

3. A reciprocating single string hollow rod pumping system for use in an oil or underground water gas well having a well casing, said system comprising:

(a) a pump piston having an internal chamber, an upper end and a lower end, wherein said upper end is adapted to engage a hollow sucker rod such that the internal chamber is in fluid communication with the hollow sucker rod, and wherein said lower end defines a fluid intake opening operatively controlled by a fluid intake check valve;
(b) a stationary string through which the hollow rod string may pass comprising a J
slot joint, a S slot joint, a slip joint and a pump barrel having a pump chamber which may receive the pump piston;
(c) a slip positioned on the slip joint which is moveable between a casing engaging position and a travelling position;
(d) friction belts for resisting rotational and reciprocal movement of the stationary string within the well casing;
(e) a slip actuating cone;
(f) a first pin provided on the exterior of the hollow rod string;
(g) a J slot provided in the J slot joint for receiving the first pin;
(h) a second pin provided on the slip joint; and (i) a S slot provided in the S slot joint for receiving the second pin;
wherein the first pin, J slot, second pin and S slot are operative substantially in the manner described herein.

4. The system of claim 3 further comprising a rod string heating means.

5. The system of claim 5 wherein the rod string heating means comprises an AC
current power source and a conduit connecting the power source with the rod string.

6. The system of claim 6 wherein the AC current heats the rod string by means of Kelvin's skin effect and proximity effect.

7. The system of claim 7 wherein the rod string is heated to about 100 degrees C.

8. A method of setting in one trip a down hole pump through a pump hunger for use with a hollow sucker rod within a well bore having a well casing, said pump comprising a pump barrel defining a pump chamber and a pump piston defining an internal chamber, said pump piston having an upper end which engages the hollow sucker rod, said method comprising the steps o~
(a) providing a pin associated with the hollow sucker rod which releasably engages the pump barrel such that the pump piston is positioned within the pump chamber;
(b) providing friction and centralizing means about the circumference of the pump barrel which engages the well casing for preventing free reciprocal, lateral and rotational movement of the pump barrel within the wellbore;
(c) providing releasable slip means associated with the pump barrel for engaging the well casing to prevent vertical movement of the pump barrel within the well bore;
(d) lowering the sucker rod and pump barrel assembly into the well bore until the pump barrel is at a desired or predetermined depth;
(e) releasing the pump barrel from the tool after while actuating the slip means to secure the pump barrel; and (f) commencing pumping by reciprocating the pump piston within the pump barrel by reciprocating the hollow sucker rod from the surface.