US3311063A - Method of pumping wells drilled below water - Google Patents

Description

March 28, 1967 B, G ABLE 3,311,063

METHOD OF PUMPING WELLS DRILLED 'BELOW WATER,

iled Dec. 10, 1965 392 Sheets-Sheet 1 a. 11 I 3 gg xaf LINE PRODUCTION as-X f N VEN 7'02. Do/vam/v B. Gene/.5

" QM #W March 28, 1967 Filed Dec. 10, 1965 D. B. GRABLE 3,311,063

METHOD OF PUMPING WELLS DRILLED BELDW WATER 2 Sheets-Sheet B ens/Iv;

PUMP CONTROL fm/wroe. Dana vq/v B. 02921.5

3,311,063 METHOD OF PUMPING WELLS DRILLED BELOW WATER Donovan B. Grable, Long Beach, Calif., assignor of onethird to K. L. Bourdo, Phoenix, Ariz., and one-third to C. R. Summers, Houston, Tex.

Filed Dec. 10, 1965, Ser. No. 512,954 12 Claims. (Cl. 103-43) This invention has to do with the pumping of wells drilled beneath water as at offshore locations in the ocean. More particularly, the invention relates to novel methods for pumping of such wells by the employment of floated energy for stroking well pumps operated by vertically reciprocable rod strings.

Offshore wells may be produced using conventional pumps whose strokes can be of considerable length, e.g. around 20 feet and greater, although the invention is not limitative in this respect. Adding to the well depth the water depth above, considerable energy is required for pumping elevation of production to the water surface.

The present invention is predicated upon the derivation of such energy at least in part, by economical means employing a pump actuating barge connected to the rod string and operating in an essentially reciprocally floating manner to cause pumping reciprocation of the rod string. In this manner it becomes possible to employ the energy of natural water movements where available, for pumping displacement of the barge, and largely to limit otherwise powering of the barge to reverse movements for which the barge resistance may be reduced, as will apear. p A further important feature of the invention is the employment of such pumping barge for reception and storage of production from the well. Thus the barge may be equipped for oil storage from which the oil may be taken to larger capacity shipping vessels. If desired, the barge may have additional facilities for the accommodation or treatment of gas released from the well, such for example as an oil-gas separating unit for the recovery of liquid or liquefiable hydrocarbons in the gas.

In its equipment aspects, the invention contemplates the provision of appropriate production pipe or tubing extending upwardly from the well and within which the pump rod string extends. The rod string is connected to the barge by a flexible cable extending thereto from what may be termed a guide location, in relation to which the barge may have reciprocating movement in different radial directions.

A further feature and object of the invention involves the exertion of counter loading of the pump and string so as to control or minimize the pumping power required of the barge under either water motion or motor driven influence.

All the features and objects of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description of the accompanying drawing, in which:

FIG. 1 is a general view, diagrammatic in parts, showing an illustrative well installation and associated pumping barge;

FIG. 2 is a plan view of the barge assembly; and

FIG. 3 is an enlarged showing of the wire line guide and control assembly as viewed from line 33 of FIG. 1.

In reference first to the generalities of the system, an oil well is shown to be located in the formation 11 underlying a body of water 12 as at at an off-shore ocean location where the height of the well superstructure generally indicated at 13, will be predetermined accordingly. At its surface the water normally may be in a state of current flow, causing displacement of the barge generally United States Patent 07 3,311,063 Patented Mar. 28, 1967 indicated at 14, or the water condition may be relatively quiescent, requiring greater powered displacement of the barge.

The well 10 is shown to comprise a usual combination of a casing 15 having a conventional head 16, and containing tubing 17 which receives production entering through the casing perforations into the bottom of the tubing, the oil being elevated by a pumb 19 operated by vertical reciprocation of the attached rod string 20. The casing head 16 mounts a conventional tubular riser 21 that may accommodate a usual blowout preventor 22 and gas seal packer 23. Within its upper extent the riser 21 receives the tubular support 24 having a wire line control head generally indicated at 25, and which establishes the guide location for a line or cable 26 connected at 27 to the upper end of the rod string 20 and extending to a connection at 28 with the barge 29. The support 24 preferably is mounted for vertical adjustment above the riser 21 in a suitable manner as typified by a releasable clamp ring 30 at the top of the riser. Any suitable means, merely typified by guy cables 31, may be employed to support and laterally stabilize the superstructure 13.

The wire line control head maybe of usual design comprising, e.g. 'a lateral arm 32 extending from collar 33 which swivels on the support 24, the arm inturn carrying a post 34 which mounts the cable sheave 35. Thus the cable 26 extends about the sheave to the barge and the sheave together with its'mounting bodily swivels about the support 24 in accordance with the radial direction of the cable 20 running to the barge. Generally it is preferred to maintain the head assembly 25 near the surface of the" water, and where the water level is subject to periodic changes, the elevation of the assembly 25 may be adjusted accordingly.

The barge 29 is shown diagrammatically to carry oil storage facilities as within the hold of the barge or a tankage 37 into which oil elevated by the pump into riser 21 is delivered by way of line 38. The barge may carry an added facility 39 for the reception of gas from the well through line 40, the facility 39 being e.g.' conventional equipment for separating or recovering liquid or condensible hydrocarbons from the gas.

In the broad contemplation of the invention, the barge 29 may be equipped with any suitable means operable to enhance displacement of the barge by such water currents or flow as may exist at the well location. As illustrative, such means generally indicated at 42 may comprise a pair of vanes 43 pivoted at 44 to swing between the solid line projected positions and contracted broken line positions of FIG. 2 in response to suitable actuation as by piston 45 operating within cylinder 46 and pivoted at 47 to the vane arms 48. Hydraulic fluid is delivered to the cylinder 46 for the piston and vane actuation from pump 49 through line 50 under control of four-way valve 51 which also governs the cylinder return flow through line 52. The valve 51 may be associated with an appropriate remote control 53. The pump 49 is shown to be powered by the barge engine 54 which also operates reversibly to drive propeller 55 which powers the barge in its pumping displacement.

Referring particularly to FIG. 3, the assembly 25 is shown to include also a drum 56 about which is spooled cable 57 supporting a counterweight 58, the latter being of sufficient mass or Weight to substantially counterbalance the weight of the pump rod string 20 so that the pumping load or pull to be exerted by the barge will essentially be that required for elevation of the pumped liquid column with only that excess attributable to the weight of the rod string, sufficient to allow the string to lower when the barge pull is released. Force transmission between the barge and counterweight 58 through the as- C; sembly 25 requires in effect keying of the sheave 35 and spool 56 to the shaft S. To anticipate variance in the transmission by reason of consequential slippage of the cable 26 on the sheave 35, that section of the cable as between the locations 60 and 59 which reciprocally travels the sheave, may be replaced by chain section 20a with the sheave sprocketed to have non-slipping retention of the chain.

In considering the operation of the system, the pump 19 may be assumed to operate at considerable stroke upon by the water flow in the direction of its movement.

Approaching the limit of the pump upstroke the vanes may be retracted and the barge then reversely powered by its propeller 55. In the absence of natural water movement, the barge may be reciprocally powered Within the v limits of the pump stroke by reversely driving the propeller.

I claim:

1; The method of operating a pump withina well below a body .of water by vertical reciprocation of a rod string connected to the pump, that comprises connecting liquid separating facility and gas is conducted from the Well to said facility.

4. The method of claim 1, in which the barge is motor driven in at least one direction of its reciprocal movements.

5. The method of claim 4, in which the barge is displaced in one direction by movement of the water and is motor driven in a generally opposite direction.

6. The method of claim 1, including also the step of variably elevating said guide location in accordance with changes in the water level.

7. The method of claim 1, in which the rod string is counterweighted and the barge elevates the counterweighted string.

the rod string with a barge on the water by a flexible line leading to the barge from a guide location, and reciprocally moving the barge in relation to said location to vertically reciprocate the rod string.

8. The method of claim 7, in which the barge is equipped for oil storage and oil is pumped by said pump into the barge.

9. The method of claim 9, in which the barge has a liquid-gas separating facility and gas is conducted from the Well to said facility.

10. The method of claim 4, in which the barge is motor driven in at least one direction of its reciprocal movements.

11. The method of claim 8, in which the barge is displaced in one direction by movement of the water and is motor driven in a generally opposite direction.

12. The method of claim 11, including also the step of variably elevating said guide location in accordance with changes in the water level.

References Cited bythe Examiner UNITED STATES PATENTS ROBERT M. WALKER, Primary Examiner.

Claims (1)

1. THE METHOD OF OPERATING A PUMP WITHIN A WELL BELOW A BODY OF WATER BY VERTICAL RECIPROCATION OF A ROD STRING CONNECTED TO THE PUMP, THAT COMPRISES CONNECTING THE ROD STRING WITH A BARGE ON THE WATER BY A FLEXIBLE LINE

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