ORTABLE PUMP ROD PULLER
CROSS REFERENCE APPLICATIONS
This application is a non-provisional application claiming the benefits of provisional application no. 60/368,057 filed March 26, 2002.
FIELD OF INVENTION
The present invention relates to a device for lifting a dewatering pump located in an underground gas production well from a build up layer of sand or silt blocking the pump operation. The present invention eliminates the need for a conventional mechanical drilling or "workover" rig through the use of hydraulics.
BACKGROUND OF THE INVENTION
Dewatering pumps for production wells can be located several hundred feet below ground. Fine materials such as sand, silt or clays, which surround the well, may enter the well casing during normal operations. An accumulation of the fine materials can cause the dewatering pump located in the well casing to cease operation. When this happens, the well space fills with water, preventing the gas being produced from entering the well casing. To free the "stuck" dewatering pump rotor, a conventional mechanical drill rig or workover rig must be brought in to mechanically lift the pump rotor out of the sand layer which entraps the rotor. The conventional workover drill rig is an extremely heavy and cumbersome piece of equipment. A workover rig takes a considerable amount of
time to maneuver, sometimes several hours to move from one location to another. At times, it is much too large a piece of equipment than that needed to perform the freeing task. When used to pump out sand buildup, mechanical rigs can often exert too much pressure, causing damage to or failure of the pump rod (or polished rod) . A workover drill rig can also be associated with high handling costs.
The present invention offers the advantage of a hydraulic system over the conventional mechanical rig. Where the mechanical system generally exerts a non- adjustable amount of pressure or force depending on the size of the rig, a hydraulic system allows an operator to evaluate the degree of entrapment and adjust the amount of pressure or force required to free the entrapped pump rotor from sand buildup in a well casing. With the hydraulic system, the operator has the ability to pull the pump at a lower degree of pressure or force than when using a mechanical system. If the initially exerted pressure or force is not sufficient to free the pump, the system can be re-engaged to exert a higher degree of pressure or force. If the operator determines the hydraulic system is insufficient to free the pump, the operator may then opt to bring in a mechanical rig. Further, the present invention provides an operator with the ability to stabilize the rod and tool to reduce the chance of damage to or failure of the pump rod caused by rotation.
Efforts have been made to develop various types of lifting apparatus for use in well workovers and well servicing operations. In particular, a portable or compact apparatus has been invented for replacing a large conventional well rig for lifting a wellhead and
production tubing string in certain well servicing or workover applications. U.S. Pat. No. 4,756,366 which issued to Maroney et al . on Jul . 12, 1988 and is entitled "Well Servicing Methods Using A Hydraulic Actuated Workover Mast" , discloses a portable workover rig for lowering and raising objects such as pipe into and out of a borehole. The workover rig is mounted to a heavy vehicle and includes a mast which can be raised from a horizontal to a vertical position, a hydraulic system and drum cable system. Nevertheless, the portable workover rig disclosed in this patent is expensive to construct and operate because a dedicate vehicle, a dedicated hydraulic system and a complicated mechanical structure are involved. Moreover, the portable workover rig is designed to lift a wellhead for well servicing or workover .
The present invention performs the task of freeing a stuck pump rotor without the removal of the prior art wellhead, which is usually performed by bringing in a mechanical workover rig. Dissembling the drive head normally takes 5-6 hours. The present invention can quickly free a stuck pump rotor after 10 minutes of setup time.
U.S. Pat. No. 3,998,428 which issued to Miles on Dec. 21, 1976 and is entitled "Well Pipe Extractor And Installer" , discloses a well pipe puller that uses a pair of gripping jaws mounted to a pair of vertical supports for clamping a well pipe. The jaws of arcuate configuration have gripping teeth, and are urged into a closed gripping position by spring activation. The hydraulic cylinders that pull the well pipe reside within the vertical supports. Miles addresses the cumbersome and costly labor approaches of having one workman manually
pull up the well pipe with a pipe wrench while another workman clamps the pipe at the ground level with another pipe wrench to prevent the lowering of the pipe into the well bore at an uncontrolled rate. Miles, however, still requires the removal of the full wellhead.
U.S. Pat. No. 6,234,253 which issued to Dallas on May 22, 2001 and is entitled "Method And Apparatus For Well Workover Or Servicing" , discloses a method and apparatus that uses hydraulic cylinders to lift a wellhead, a production tubing string, or a wellhead with an attached production tubing string for servicing or working over a hydrocarbon well . The apparatus is mounted on a skid assembly. A pair of hydraulic cylinders pivots from a horizontal to a vertical position. A workover beam and rotatable lifting sub pull the wellhead and/or production tubing in an upward direction. Dallas, however, still requires the removal of the full drive head down to the well casing.
A tool useful in pulling casing from a dead well is illustrated in U.S. Pat. No. 2,661,063, which issued to Owens on Dec. 1, 1953 and is entitled "Method And Means Of Pulling Pipe From A Well". Owens discloses the use of a pair of hydraulic jacks to loosen a casing that gets stuck while being pulled from a dead well by a rig. The jacks exert an upward force through two arms affixed to a collar attached by shearable pins to the well casing being pulled by the rig. The pins shear unless the well casing pipe dislodges from the stuck position. The shearing of the pins causes a downward jar or jerk on the pipe that tends to loosen the pipe. After the well casing pipe is loosened, it is pulled from the well using the rig until it is removed, or it gets stuck again. Like the present invention, the hydraulic jacks are not designed
to lift a wellhead for well servicing or workover. However, in Owens, the pipe being lifted by the jacks is the well casing pipe, not the polished rod which extends from the dewatering pump located in the well casing as in the present invention.
As stated above, the present invention performs the task of freeing a stuck dewatering pump rotor without the removal of the prior art wellhead.
Other advantages offered by the present invention are its compact nature and its portability. The present invention can be transported in a small truck to a well site in a fraction of the time it would take to maneuver a conventional work-over rig into place.
Another advantage of the present invention is the cost savings that can be realized associated with its portability, compactness and ease of installation.
Yet another advantage of the present invention is the ease of installation onto the well drive. In most instances, in which the long stroking tool is used to free a pump, the production well can be up and running again in less than one hour.
SUMMARY OF THE INVENTION
The main aspect of the present invention is to implement a hydraulic system to free a dewatering pump rotor located in a production well that is entrapped in a layer of fine materials such as sand, silt or clays which normally surround the well but may enter the well casing to block the normal operation of the dewatering pump.
Another aspect of the present invention is that it gives an operator the ability to adjust the amount of pressure required to free a stuck pump rotor from sand
buildup within the well casing. By adjusting the degree of pressure or force exerted when pulling the pump rod with the present invention, the operator reduces the chance to cause damage to or failure of the polished rod. Another aspect of the present invention is its ability to utilize existing components of a prior art wellhead setup, such as a lower rod lock and upper rod lock/drive, to facilitate the pulling of the polished rod. Another aspect of the present invention is its portable nature. The present invention can be transported in a small truck to a well site in a short amount of time .
Another aspect of the present invention is its compact nature, allowing an operator to mobilize the suitably sized long stroking tool with a small truck instead of having to mobilize an over-sized piece of equipment, which could cause damage to or failure of the polished rod. Another aspect of the present invention is to allow the operator to stabilize the rod and tool to further reduce the chance of damage to or failure of the pump rod caused by rotation.
Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view of one embodiment of the apparatus mounted on top of the prior art wellhead.
FIG. 2 is a plan view of the polish rod extension and the prior art wellhead setup.
FIG. 3 is another frontal view of the apparatus mounted on top of the prior art wellhead.
FIG. 4 is a frontal view of the apparatus.
FIG. 5 is a side view the embodiment of Fig. 4.
FIG. 6 is a top perspective view of a front or back surface of the upper plate of the embodiment of Fig. 4.
FIG. 7 is a top view of the bottom surface of the upper plate of the embodiment shown in Fig. 4.
FIG. 8 is a side view of the bottom surface shown in Fig. 7.
FIG. 9 is a plan view of the bottom surface shown in Fig. 7.
FIG. 10 is a top view of the bottom surface of the lower plate of the embodiment shown in Fig. 4.
FIG. 11 is a side view of the bottom surface shown in Fig. 10
FIG. 12 is a plan view of the bottom surface shown in Fig. 10.
FIG. 13 is a front view of the upper plate of the embodiment shown in Fig . 4.
FIG. 14 is a side view of the upper plate shown in Fig. 13.
FIG. 15 is a side view of a hydraulic cylinder pin.
FIG. 16 is a front view of the hydraulic cylinder pin shown in Fig. 15.
FIG. 17 is a front view of a hydraulic cylinder pin lug.
FIG. 18 is a side view of the hydraulic cylinder pin lug shown in Fig. 17.
FIG. 19 is a plan view of a hydraulic cylinder pin lug shown in Fig. 17.
FIG. 20 is a front cross sectional view of another embodiment of the apparatus mounted on top of the prior art wellhead.
FIG. 21 is a cross sectional view of the embodiment of Fig. 20.
FIG. 22 is a top perspective view of another embodiment of the apparatus .
Before explaining the disclosed embodiments of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangements shown, since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view of one embodiment of the
long stroking tool 1000. Tool 1000 is shown mounted on top of a prior art wellhead.
A pump having a rotor (not shown) is located underneath the ground surface S. The pump rotor (not shown) is located at the lower end of existing pump rod (or polished rod) 3000. Fine materials surrounding the well may enter the well casing 400 beneath ground surface S and accumulate around the pump rotor (not shown) , thereby causing the pump (not shown) located in the well casing 400 to cease operation.
As shown in FIGS. 1 and 4, long stroking tool 1000 comprises lower plate 3400 and upper plate 3500, which are preferably made of steel. Plates 3400 and 3500 are attached to hydraulic cylinders 3600, 3700 by means of a hydraulic lug pin(s) 4600. Connectors 800 and 900 connect hydraulic hose 3300 and hydraulic cylinders 3600 and 3700. Connectors 801 and 901 connect hydraulic hose 3200 and hydraulic cylinders 3600 and 3700. One end of hydraulic hose 3200, 3300 is connected to a control valve assembly 4300. Hydraulic hoses 4450 and 4550 connect prior art portable hydraulic power unit 4400 (not shown) and prior art pump 4500 (not shown) . The example in FIG. 4 shows the use of quick couplers. However, the present invention is not limited to quick couplers since various factors may affect the size and materials selected for particular well site requirements.
As shown in FIGS. 4,5, 13, and 14, upper plate 3500 comprises a front and back surface 3540 and a bottom surface 3520. Bottom surface 3520 is depicted in FIGS. 7- 9 as having a hole 3530 mounted therethrough. Lower plate 3400 comprises a front and back surface 3440 and a bottom surface 3420. Bottom surface 3420 is depicted in FIGS. 10-12 as having a rectangular opening 3430 mounted
therethrough. The front and back surfaces 3540 of upper plate 3500 and the front and back surfaces 3440 of lower plate 3400 are as shown in FIG. 6, a top perspective view of a front or back surface of the upper plate of the embodiment of FIG. 4.
Referring to FIG. 13, the ends of upper plate 3500 comprise hydraulic pin lug 4700. FIGS. 17-19 show hydraulic cylinder pin lug 4700 having a hole 4750 mounted therethrough. FIGS. 15-16 show a hydraulic cylinder pin 4600. As seen in FIG. 4, upper plate 3500 is attached to hydraulic cylinders 3600, 3700 by inserting hydraulic lug pin 4600 through pin lug hole 4750. The ends of lower plate 3400 similarly comprise a hydraulic pin lug 4700 having a hole 4750 mounted therethrough. Lower plate 3400 is attached to hydraulic cylinders 3600, 3700 by inserting hydraulic lug pin 4600 through pin lug hole 4750.
FIG. 2 is a plan view of the polished rod extension 3800 and the prior art wellhead setup. Polished rod 3000 extends from the interior of well casing 400 through bracket 3100. (See FIG. 1.) Polished rod 3000 is held in place by the existing upper rod lock/drive 300. Upper rod lock/drive 300 is located above the existing drive head 500 and hydraulic motor drive 2000. Polished rod extension 3800 of the present invention may be installed to extend the length of polished rod 3000, thereby providing greater access to polished rod 3000 when mounting the long stroking tool 1000. Existing bracket 3100 houses lower rod lock 100 and existing packing gland 200.
As shown in FIG. 1, polished rod 3000 is held in place by the existing upper rod lock/drive 300. Upper rod lock/drive 300 is loosened to allow rod 3000 to slide
up through the well casing 400. However, lower rod lock 100 is first tightened to hold rod 3000 in place, thereby preventing rod 3000 from sliding down into the well casing 400 when the upper rod lock/drive 300 is loosened. In this tightened configuration, lower rod lock 100 is positioned directly over packing gland 200. As rod 3000 is pulled in direction F to free the "stuck" pump rotor (not shown) , lower rod lock 100 is also pulled in direction F and away from packing gland 200. To implement the invention, tool 1000 is mounted over existing rod 3000 or extension 3800 thereof by positioning rod 3000 or extension 3800 through the rectangular opening 3430 of lower plate 3400 and hole 3530 of upper plate 3500. Tool 1000 is positioned on top of loosened upper lock/drive 300. Bushing 3900 is then installed on rod 3000 as rod 3000 protrudes through hole 3530 at the top of upper plate 3500. Bushing 3900 is seated on bottom surface 3520 of upper plate 3500 between the front and back surfaces 3540 to allow rod 3000 to freely rotate without moving tool 1000.
Lifting rod lock or temporary rod lock 4000 is then installed on rod 3000 as it protrudes through bushing 3900 on top of upper plate 3500. When tightened, lifting rod lock 4000 is positioned on top of bushing 3900 to keep the tool 1000 and bushing 3900 in place. To keep tool 1000 from rotating, anti-rotation chains 4100, 4200 having chain bearings extend from bottom surface 3420 of lower plate 3400 and attach to existing eyehooks 600, 700 on drive head 500. These figures depict one example of the present invention. Various factors would obviously affect the selection of the type, size, and placement of materials, as well as dimensions and tolerances required for
particular well sites and thus, the range of design is not limited to these examples .
For example, plates 3400 and 3500 of tool 1000 are attached to hydraulic cylinders 3600, 3700 by means of a hydraulic lug pin(s) 4600. However, as set forth in FIG. 22, another embodiment of the present invention, the upper plate 9000 comprises a first portion 9010 and a second portion 9020, wherein the two portions are removably secured together by bolts or clamps 9050, 9060. The lower plate 9100 comprises a first portion 9110 and a second portion 9120, wherein the two portions are removably secured together by bolts or clamps 9150, 9160.
Upper plate portion 9010 and lower plate portion 9110 are affixed to a hydraulic cylinder 9200, preferably by means of hydraulic lug pins (not shown) inserted through pin lug holes 9550 of hydraulic pin lug 9500. Accordingly, upper plate portion 9020 and lower plate portion 9120 are affixed to hydraulic cylinder 9300, preferably by means of hydraulic lug pins (not shown) inserted through pin lug holes 9450 of hydraulic pin lug 9400. Upper portions 9010, 9020 and lower portions 9110, 9120 are configured to abut opposing sides of the outer circumference of polished rod 3000 or, if necessary, extension 3800. FIG. 3 is another frontal view of tool 1000 mounted on top of the prior art wellhead. Tool 1000 comprises lower plate 3400 and upper plate 3500 connected to hydraulic cylinders 3600, 3700. Operator U is shown tightening lifting rod lock 4000 which is positioned on top of bushing 3900. Hydraulic hoses 3600, 3700 are shown connected to hydraulic cylinders 3600, 3700.
FIG. 1 also depicts prior art control valve assembly 4300 connected to one end of hydraulic hoses 3200, 3300.
Another end of hydraulic hoses 3200, 3300 is connected to intake valves (not shown) located on hydraulic cylinders 3600, 3700 of tool 1000. When the control valve is activated, thereby passing hydraulic fluid through hydraulic cylinders 3600 and 3700, hydraulic cylinders 3600 and 3700 extend, causing upper plate 3500 to pull pump rod 3000 in direction F. Control valve assembly 4300 is fitted with an adjustable relief valve (not shown) to control the amount of force exerted by tool 1000. The pressure to be exerted can range from 0-3000 psi. Thus, the range of force can be 0-30 or more tons. Although one example of the disclosed embodiment was operated in the range of 1500-3000 psi (or 10-30 tons) , various factors would obviously affeet ' the degree of pressure (or force) required for particular well sites. Thus, the range of operation is not limited to 1500-3000 psi (or 10-30 tons) . Hydraulic hoses 4450 and 4550 connect prior art portable hydraulic power unit 4400 and prior art pump 4500. As rod 3000 is pulled in direction F to free the "stuck" pump rotor (not shown) , lower rod lock 100 is also pulled in direction F and away from packing gland 200. If the pump rotor is not freed up, lower rod lock 100 is loosened, positioned back down to seat directly over packing gland 200, and retightened. Lower rod lock 100 may be loosened without fear that rod 3000 will slide down into well casing 400 because tool 1000 and temporary rod lock 4000 now hold rod 3000 in place. After hydraulic cylinders 3600, 3700 are retracted, the pulling process is repeated until the entrapped pump rotor is freed.
FIGS. 20-21 depict another embodiment of the apparatus of the present invention. Tool 8000 is mounted on top of prior art wellhead 500. As shown, tool 8000 has
no plates. Tool 8000 comprises cylinder barrel 6500 and hydraulic cylinder 6300.
To implement the invention, tool 8000 is mounted over existing rod 3000 or extension 3800 thereof by positioning rod 3000 or extension 3800 through hollow center casing 6600 of hydraulic cylinder rod 6300. The bottom portion of center casing 6600 is welded to the bottom portion 6320 of hydraulic cylinder rod 6300 to guide cylinder rod 6300 through cylinder barrel 6500. Tool 8000 is positioned on top of loosened upper lock/drive 300. The bottom 6700 of cylinder barrel 6500 is notched out to fit partially over upper rod lock/drive 300.
Bushing 7000 is then installed on rod 3000 as rod 3000 protrudes through center casing 6600 at the top of hydraulic cylinder rod 6300. Bushing 7000 is seated within the upper portion 638Oof hydraulic cylinder 6300 to allow rod 3000 to freely rotate without moving tool 8000. Lifting rod lock or temporary rod lock 6000 is then installed on rod 3000 as rod 3000 protrudes through bushing 7000 on top of hydraulic cylinder 6300. When tightened, lifting rod lock 6000 is positioned on top of bushing 7000 to hold tool 8000 and bushing 7000 in place. To keep tool 8000 from rotating, anti-rotation chains 6100, 6200 having chain bearings extend from the bottom portion of cylinder barrel 6500 and attach to existing eyehooks 600, 700 on drive head 500.
Hydraulic hoses (not shown) are connected to intake valves (not shown) located on cylinder barrel 6500 by means of quick couplers 6800, 6850. The present invention is not limited to the use of quick couplers since various factors may affect the size and materials selected for particular well site requirements. As hydraulic fluid
passes through the system of tool 8000, hydraulic cylinder rod 6300 extends through cylinder barrel 6500 until the lower portion 6320 of hydraulic cylinder rod 6300 encounters cylinder gland 6340. The extension of hydraulic cylinder rod 6300 causes lifting rod lock 6000 to pull pump rod 3000 in direction F.
FIG. 21 is a cross sectional view of the single hydraulic cylinder embodiment of Fig. 20. Rod 3000 protrudes within center casing 6600 of hydraulic cylinder rod 6300. As hydraulic fluid passes through the system of tool 8000, hydraulic cylinder rod 6300 extends upward through cylinder barrel 6500.
Although the present invention has been described with reference to disclosed embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.