Stationary slick line pumping method
An alternative apparatus and pumping method for retrieving liquids from a wellbore without the use of a pumping unit as customarily used in oil field operations.
The present invention relates to an alternative apparatus and pumping method for retrieving liquids from a wellbore without the use of a pumping unit as customarily used in oil field operations. This unit is primarily targeted for gas well deliquification and/or low fluid volume oil or condensate wells.
BACKGROUND OF THE INVENTIONIn typical oil field operations, when liquids are recovered from oil and gas wells, the wells are equipped with a pumping unit which reciprocates sucker rods upwardly and downwardly in the well to activate a down-hole pump which pumps liquids, such as oil, water and mixtures thereof, to the surface. The maintenance of such equipment is relatively expensive, as is the equipment itself. Further in relatively low production wells it is continually necessary to adjust the speed and run time of the pumping unit, and the like to keep the level of the well liquids above the top of the pump. It is detrimental to operate a pump above the level of the liquid.
In many instances, it is desirable to remove liquids from a wellbore by a different approach. The different approach is desirably one which does not require the use of the expensive equipment or the continued adjustments based upon the level of liquids in the well.
Accordingly, a continuing search has been directed to a method for effectively removing liquids from such wells.
SUMMARY OF THE INVENTIONAccording to the present invention, such liquids are readily recovered by an apparatus for recovering liquids from a well containing a tubular member having an inside and extending from an earth surface to penetrate a liquid producing subterranean formation, the apparatus comprising: a body having a body top and a body, a round exterior surface, openings in the body top and a valve in the body; a flexible support member extending from a system for raising and lowering the flexible support member in the wellbore and connected to the body top.
In the discussion of the Figures, the same numbers will be used throughout to refer to the same or similar components.
In
In
The present invention comprises a body 42, which is shown positioned beneath the liquid level 34. The body is connected via a slick line 40 to a system for raising the body in the production tubing. The body 42 includes a top 44 and a bottom 46. The body is lowered to a position near the bottom 52 of the well. Desirably the body is lowered to a position beneath perforations 22 into subterranean formation 16. Further it may be desirable that seals (not shown) be positioned around the outside surface of the body to minimize the amount of fluid that will leak between the body 42 and tubing 28.
In the operation of the apparatus shown in
The body in its raised position is shown in
An embodiment of the body 42 is shown in
In
A variety of seals of different configurations can be used with equal success. The seals shown are considered to be illustrative of the use of seals and it should be noted that the drawings are not drawn to scale. In a preferred embodiment, the mechanical clearance between the outside of body 42 and inside 30 of production tubing 28 is maintained at very close tolerances. This permits the withdrawal of the liquid effectively by the use of the body without respect to the seals.
In some applications, it is desirable to have seals rather than closer tolerances since it is considered that the seals can be more effectively lowered into the liquid layer than can a very tightly toleranced body. Typically when no seals are used it is desirable that the clearance between an outer surface of the body 42 and the inside surface of the production tubing be such that a very small amount of liquid would flow past the body 42. Somewhat larger tolerances between outer surface and the inside of the production tubing may be used when seals are used since the seals will facilitate prevention of leakage of liquids past the body.
In
The operation of the apparatus of the present invention is effective to lower the body into a well through a layer of liquid and to withdraw the body upwardly through the well to discharge liquids through a recovery line. This permits the recovery of significant amounts of liquids from wells which may not produce enough liquid to justify maintaining pumping unit equipment at the well. Further it does not require extensive control of the level since if the level rises too high it will simply be recovered through the recovery line 32 and the well can then be emptied using the slick line and the body at intervals as desired. The alternate pumping system of the present invention can also be used to operate wells of higher production but more frequent operation of the recovery cycle is necessary. Further the recovery cycle can be automated to run at selected intervals with only infrequent attention from the operator although it is anticipated that the operator of the well will periodically operate the well manually as required. This application also allows the operator of low liquid volume wells to set this application below perforations 16 if desired to further lower the bottom-hole pressure. Currently with most other forms of artificial lift, it is not recommended to set the pump intake below the perforations.
A further application of the present invention is the removal of liquids which may accumulate in low pressure gas wells. In such wells, the gas may be produced at a pressure sufficiently low that it will not flow upwardly through the liquid layer. In such instances, lowering the liquid layer to a sufficiently low level is crucial to the production of the natural gas. Accordingly, it is clear that the apparatus of the present invention and the method of the present invention can be used for a variety of purposes such as the operation of recovery from a relatively high producing well to recovery of liquids from a relatively low producing well or for the removal of undesired liquids from low pressure gas wells.
Furthermore this application lends itself to be powered by a standard electricity source such as power lines, or by alternative energy sources such as solar power, wind generators or any other alternative energy source that generates clean reliable energy.
While not discussed above, it will be understood that the apparatus of the present invention could also be used inside a casing as it is used inside production tubing. In such instances, the body must be configured to suitably interact with the inside surface of the casing. In other respects the operation is the same as discussed above for operation of production tubing. This may also be desirable in some wells since it may be used in wells which are not fully completed or from which the tubing has been withdrawn. In some instances it may be desirable to limit the amount of liquid which is positioned for removal by the slick line withdrawal. Weight considerations may require that the amount of liquid which could be moved upwardly by the body be limited to the weight lifting capacity of the slick line.
The liquids recovered are typically petroleum, petroleum distillates, water, brine, and mixtures thereof. The gas recovered typically comprises natural gas. The recovery of these valuable materials is facilitated by the use of the present invention in instances where it is not desirable or feasible to use a pumping unit with a submersible pump and the like.
While the present invention has been described by reference to certain of its preferred embodiments, it is pointed out that the embodiments described are illustrative rather than limiting in nature and that many variations and modifications are possible within the scope of the present invention. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments.
Claims
1. An apparatus for recovering liquids from a well containing a tubular member having an inside and extending from an earth surface to penetrate a liquid producing subterranean formation, the apparatus comprising:
- a) a body having a body top and a body, a round exterior surface, openings in the body top and a valve in the body;
- b) a flexible support member extending from a system for releasing and retrieving the flexible support member in the wellbore and connected to the body top
2. The apparatus of claim 1 wherein the valve is a ball valve.
3. The apparatus of claim 1 wherein the valve is a flapper valve.
4. The apparatus of claim 1 wherein the tubular member is a production tubing.
5. The apparatus of claim 1 wherein the body top includes at least one hole.
6. The apparatus of claim 1 wherein the flexible support member comprises at least one of a braided wire line, slick line and polymer line.
7. The apparatus of claim 1 wherein the clearance between the outside of the body and the inside of the tubular member is a tight mechanical tolerance such that minimal fluid will pass by the outside of the body.
8. The apparatus of claim 1 wherein seals are positioned on the exterior surface of the body to reduce leakage of fluids between the outside of the body and the inside of the tubular member.
9. The apparatus of claim 1 wherein the tubular member is a casing.
10. A method for producing fluids from a well containing a tubular member having an inside and extending from an earth surface to penetrate a fluid producing subterranean formation, the method comprising:
- a) positioning an apparatus comprising a body having a body top and a body, a round exterior surface, openings in the body top and a valve in the body in the well;
- b) connecting the apparatus to a flexible support member to lift and lower the body;
- c) producing liquids from the well by raising the body; and,
- d) lowering the body into the well.
11. The method of claim 11 wherein the fluid comprises at least one of petroleum, distillates, water and natural gas.
12. The method of claim 11 wherein the well is a low fluid production well producing at least petroleum, natural gas, distillates and water.
13. The method of claim 11 wherein the tubular member is a production tubing and wherein liquids are produced by lifting the body through the production tubing.
14. The method of claim 11 wherein the tubular member is a casing and wherein liquids are produced by lifting the body through the casing.
15. The method of claim 11 wherein the well is a low pressure gas well which also produces liquids wherein the liquids are removed to enable the production of gas.
16. The method of claim 11 wherein the body is lowered by opening the valve and allowing liquids to flow into the body and out of the body through the valve and at least one hole in the body top.
17. The method of claim 11 wherein natural gas is produced from the well by periodic removal of liquids.
18. The method of claim 11 wherein the flexible support member comprises a wire line, slick line or polymer line.
Type: Application
Filed: Aug 13, 2007
Publication Date: Feb 19, 2009
Inventor: Aaron Mathew Hunter (Midland, TX)
Application Number: 11/891,826
International Classification: E21B 43/00 (20060101);