GB2358202A

GB2358202A - Methods for boosting hydrocarbon production

Info

Publication number: GB2358202A
Application number: GB0000653A
Authority: GB
Inventors: Kashmir Singh Johal; Timothy Miles Lower; Simon Gerald Bailey Dawson
Original assignee: Mentor Subsea Technology Services Inc
Current assignee: Mentor Subsea Technology Services Inc
Priority date: 2000-01-12
Filing date: 2000-01-12
Publication date: 2001-07-18
Also published as: BR0100053A; NO20010146D0; US20010007283A1; GB0000653D0; NO20010146L

Abstract

A hydrocarbon production technique uses the local raw water injection system 12 to use the minimally processed sea water as the hydraulic power fluid for the downhole turbine/pump equipment 18. In one embodiment, the raw water provides the hydraulic power to the downhole equipment via the production well annulus 22 in an open loop arrangement. The production fluids exit the pump assembly via ports [52, fig. 2] and are co-mingled with the the power fluid which exit the pump assembly via exhaust ports [50, fig. 2]. The fluids are co-mingled and pumped up the tubing [24, fig 2] to the well head 21. In another embodiment the production fluids and power fluids are exhausted separately with the power fluid being returned to the raw water injection system 12 and reused. In a further embodiment the power fluid is discharged from the turbine and conveyed to a suitable formation for injection via a dual completion well.

Description

2358202 METHODS FOR BOOSTING HYDROCARBON PRODUCTION The invention

generally relates to the production of oil and more particularly to methods for boosting 5 hydrocarbon production.

In the production of oil, it is often necessary to boost the pressure of the produced fluids in order to achieve the required production rates. Current downhole pressure boosting methods include the injection of water into the oil bearing formation, well bore gas lift, electrical submersible pumps, and hydraulically driven, downhole turbine/pump arrangements.

Respective aspects of the invention are set out in claims 1, 2 and 3.

Preferred techniques use locally generated, minimally treated sea water (raw water) injection equipment to provide the hydraulic power fluid for a downhole turbine/pump arrangement. In one embodiment, the raw water provides the hydraulic power to the downhole equipment-via the production well annulus in an open loop arrangement. The raw water is co-mingled with the production fluids. In another embodiment, the raw water provides the hydraulic power to the downhole equipment via the production well annulus in a closed loop arrangement. The raw water is not co-mingled with the production fluids. In another embodiment, the raw water provides hydraulic power to the downhole equipment via the production well annulus in an open loop downhole arrangement. The raw water discharged from the turbine is conveyed to a suitable formation for injection via a dual completion weli.

The invention will now be described by way of exampl with reference to the accompanying drawings, throughoul:

which like parts are referred to by like references, and il i 'I which:

Fig. 1 is a schematic illustration of one embodimen: of the invention; Fig. 2 is a longitudinal cross section at the mid plane of the hydraulic submersible pump used in th'preferred embodiment of Fig. 1; Fig. 3 is a schematic illustration of an alternativj embodiment of the invention; Fig. 4 is a longitudinal cross section at the mia- plane of the hydraulic submersible pump used in thalternative embodiment of Fig. 3; and Fig. 5 is a schematic illustration of a secoa alternative embodiment of the invention.

Fig. 1 schematically illustrates the preferre embodiment of the invention. An existing raw watei. processing and injection system 12 is used to process se I water and provide the processed water for injection int 0 411 oil bearing formation below the sea floor via piping 14 in fluid communication with wellheads 15 and water injectioi wells 16. The wellheads 15 are located at the se floor 17. The processed sea water is also use to provide the motive hydraulic power to thO downhole equipment 18 via piping 20 in fluid communication with the wellheads 21 and the production well annulus 22. The production wells are indicated by numeral 19. The raw water power fluid is co-mingled with the production fluids and transported to a receiving/processing facility not shown via piping 24. The piping 24 may be above or below the water surface.

As seen in Fig. 2, the wellhead 15 includes a power fluid isolation valve 28, and a production master valve 30. Tubing hanger 32 supports production tubing 34. Casing hanger 36 supports casing 38. The production tubing 34 is preferably equipped with ported landing nipples 40 that enable the hydraulic submersible pump assembly 42 to be installed by wireline, landed, and locked in position. A sealing packer 44 positioned between the lower end of the tubing assembly 34 and the casing 38 directs the flow of production fluids -JntO the pump assembly and isolates the power fluid. A safety valve 46 is provided at the lower end of the pump assembly 42. The safety valve 46 is controlled from the surface for shutting of f the flow of production fluids if necessary.

In operation, power fluid, locally generated and processed sea water, from the processing system 12 is directed through the power fluid valve 28 into the annulus between the tubing 34 and casing 38. The power fluid enters the pump assembly at the flow crossover 48. Downhole pump assemblies are generally known but the operation will be briefly described for the sake of clarity.

The power fluid flows through the pump assembly 42 to the turbine and causes the turbine and pump to spin. The pump provides power to help pull the production fluids f ro a the f o rma t i o n. The produc--Jon fluids exit the pump assembly t the pump discharge outlets S2 where they are co-mingled wJt6 the power fluid. The power fluid exits the pump assembiv at "the S turbine exhaust ports 50 into the annulus between the! P!,UMID assembly and production tubing. The co-mingled production f 11P i d and power fluit' flows back into the pump assembly below flow :1 L I into crossover 43. The co-m-ingled fluids exit the pump asseaib.'l the production tubing 34 and flow up the tubing tc the production master valve 30 and into the piping 24 seen irl I Fig.

1. As indicated above, the piping 24 delivers the co-m nq1led production and power fluids to a receiving/processing fa(il'ity not shown. Fig. 3 schematically illustrates an alternate embodiMEnt'l of the invention. In this embodiment, the raw water power flqid, is not co-mingled with the production fluid but s exhausted via piping 54 to the raw water processiaq and 7 injection system 12 for reprocessing and injection intO the reservoir.

As seen in Fig. 4, there are several differences frc the embodiment of Fig. 2. A second, smaller diameter casing, 56, is provided in the annulus between the first casing 38 an the production tubing 34. This defines an annulus betweO the production tubing 34 and the second casing 56 and an 41 Lnul us 2S between the first casing 38 and the second casing 56. The power fluid isolation valve 28 is in fluid communication with the annulus between the production tubing 34 and the second asling 56. The wellhead includes a turbine exhaust valve 58 which! is in fluid communication with the annulus between the first casing 38 and the second casing 56. The second casing 56 is provided with seals 60 that seal against the production tubing 34 and 7 power fluid to the production tubing direct the crossover ot annulus and into the pump assembly 42. The turbine exhaust 50 directs the power fluid into the annulus between the casing 38 and the second inner casing 56.

In operation, power fluid (processed sea water) from the processing system 12 is directed through the power fluid valve 28 into the annulus between the tubing 34 and second casing 56.

The power fluid enters the pump assembly at the flow crossover 48. Downhole pump assemblies are generally known but the operation will be briefly described for the sake of clarity.

The power fluid flows through the pump assembly 42 to the t-urbine and causes the turbine and pump to spin. The pump provides power to help pull the production fluids from the formation. The production fluids exit. the pump assembly at the pump discharge outlets 52 into the annulus between the production tubing 34 and the second casing 56. The production fluids then reenter the pump assembly before the crossover 48 and then exit the pump assembly into the production tubing 34.

The z)roduction fluids flow up through the production tubing 34 and through the master production valve to the piping 24 seen in Fig. 3. As indicated above, the piping 24 delivers the production fluids to a receiving/processing facility not shown.

The power fluid exits the turbine exhaust SO into the annulus between the first and second casings 38 and 56 and flows to the turbine exhaust valve 58. The power fluid is then directed via piping 54 to the raw water processing and injection sys_ tem. where it J_s reprocessed and injected into the reservoir.

Fig. S schematicall-ly illustrates an alternate embodim-nt, oL the -invention. In this embodiment, the raw water power f1pid is not co-mingled with the production but instead is directei to a suitable formation for injection via a dual completion well 62.

The main operation is the same as that described for ig. 3 and 4. The difference is that the power fluid from tirbine 4 irected to water injection line 4 "'Or exhaust valve S8 s d injection into the oil bearing formation.

Because many varying and differing embodiments may made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment ierein detailed in accordance with the descriptive requirement cf 'the is law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.

i 1

Claims

A method for boosting production of hydrocarbons from a well in an oil bearing formation, comprising the steps of:

a. placing a hydraulic submersible pump in the well; b. driving the hydraulic pump with locally generated and processed sea water; and c. directing the water exhaust from the hydraulic pump into a common line with the produced hydrocarbons.
2. A method for boosting production of hydrocarbons from a well in an oil bearing formation, comprising the steps of:

a. placing a hydraulic submersible pump in the well; b. driving the hydraulic pump with locally generated and processed sea water; and c. directing the water exhaust from the hydraulic pump into a separate line from the hydrocarbons for reuse.
3. A method for boosting production of hydrocarbons from a well in an oil hearing formation, comprising the Steps of:

a. placing a hydraulic submersible pump in the well; b. driving the hydraulic pump with locally generated and processed water; C. directing the water exhaust from the hydraulic pump into a separate line from the produced hydrocarbons; and d. injecting the water exhaust from the hydraulic pump into the oil bearing formation.

A method for boosting production of hydrocarbons fx,cm a well in an oil bearing formation, the met--hod beirg substantially as herein described with reference to the accompanying drawings.