High pressure intensifiers

Abstract

A hydraulic intensifier comprising a reciprocating differential piston arrangement and a controller configured to control the supply of low pressure hydraulic fluid to the intensifier is provided. The controller comprises at least one solenoid operated pilot valve and electronic operator configured to operate the pilot valve.

Claims

1. A hydraulic intensifier comprising: a first piston reciprocable in a first cylinder; a second piston reciprocable in a second cylinder; a cylindrical member configured to join the pistons so that each piston has a first face which has a greater surface area than its second, opposite face as a result of said cylindrical member, wherein the first face of each of the pistons is located at a respective low pressure side and the second face of each of the pistons is located at a respective high pressure side; a first input and a second input configured to supply low pressure hydraulic fluid to respective low pressure sides; an output configured to transport high pressure hydraulic fluid from the high pressure sides; a first solenoid operated pilot valve and a second solenoid operated pilot valve configured to control the supply of low pressure hydraulic fluid to respective ones of the inputs; and an electronic operator configured to operate the solenoid operated pilot valves configured to supply low pressure hydraulic fluid, wherein the cylindrical member is located between the first and second pistons whereby, if the low pressure fluid is applied to one of said low pressure sides, said low pressure fluid also flows from said low pressure side through the cylindrical member to the high pressure side of the other piston, wherein said cylindrical member comprises a first passageway between the low pressure side of the first piston and the high pressure side of the second piston, and a second passageway between the low pressure side of the second piston and the high pressure side of the first piston, wherein each of the passageways is provided with a respective non-return valve configured to permit flow from the low pressure side to the high pressure side.

2. An intensifier according to claim 1, wherein said electronic operator is provided by a subsea electronics module of a subsea well control system.

3. A method of producing high pressure hydraulic fluid comprising: providing a hydraulic intensifier comprising: a first piston reciprocable in a first cylinder; a second piston reciprocable in a second cylinder; and a cylindrical member configured to join the pistons so that each piston has a first face which has a greater surface area than its second, opposite face as a result of said cylindrical member, wherein the first face of each of the pistons is located at a respective low pressure side and the second face of each of the pistons is located at a respective high pressure side, and wherein said cylindrical member comprises a first passageway, between the low pressure side of the first piston and the high pressure side of the second piston, and a second passageway, between the low pressure side of the second piston and the high pressure side of the first piston, each of the passageways being provided with a respective non-return valve configured to permit flow from the low pressure side to the high pressure side; supplying low pressure hydraulic fluid to respective low pressure sides using a first input and a second input; transporting high pressure hydraulic fluid from the high pressure sides using an output; controlling the supply of said low pressure hydraulic fluid to each input using a first solenoid operated pilot valve and a second solenoid operated pilot valve; and supplying low pressure hydraulic fluid using an electronic operator configured to operate the pilot valves, wherein if low pressure fluid is applied to one of said low pressure sides, said cylindrical member applies fluid to the high pressure side of the other piston.

4. A method according to claim 3, wherein said electronic operator is provided by a subsea electronics module of a subsea well control system.

5. A method according to claim 3, further comprising alternately energizing and de-energizing the first solenoid pilot valve and/or the second solenoid pilot valve using the electronic operator.

6. A method according to claim 3, wherein the output is coupled with each of said high pressure sides.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a first embodiment of this invention; and

(2) FIG. 2 shows a second embodiment of this invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

(3) Referring to FIG. 1, a double-acting hydraulic intensifier 1 comprises first and second cylinders 2 and 2 joined by a narrower cylinder section 3. Reciprocally slidable in cylinder 2 is a piston 4 and reciprocally slidable in cylinder 2 is a piston 4, pistons 4 and 4 being joined by a cylindrical member 5 extending through and slidable in cylinder section 3. By virtue of member 5, piston 4 has a first face 6, on the left-hand side in the figure, which has a greater surface area than its second, opposite face 7 and piston 4 has a first face 6, on the right-hand side in the figure, which has a greater surface area than its second, opposite face 7.

(4) Each side of the intensifier comprises a solenoid operated pilot valve. More particularly, on each side there is: a solenoid 8 or 8 which operates a push rod 9 or 9; and a hydraulic pilot valve 10 or 10 that has two ports 11 and 12 or 11 and 12 that can be closed by a small ball bearing 13 or 13 that is loose between them. In each case, when the solenoid is de-energised, the rod 9 or 9 presses down on the ball bearing 13 or 13 by the action of a spring 14 or 14 of the solenoid to close the port 11 or 11 but allow trapped hydraulic fluid to vent to a return via port 12 or 12 and a passageway 15 or 15. When the solenoid 8 or 8 is energised, the rod 9 or 9 is moved upwards against the action of spring 14 or 14 to allow ball bearing 13 or 13 to cover the return port 12 or 12.

(5) A supply of low pressure (LP) hydraulic fluid is in communication with valves 10 and 10 via passageways 16 and 16 respectively. On the side of pistons 4 and 4 with smaller area faces (the high pressure sides), there are chambers 17 and 17 respectively, on the opposite (low pressure) sides there being chambers 18 and 18. The valves 10 and 10 are linked with chambers 18 and 18 via input passageway 19 and 19 respectively.

(6) Chamber 18 is in communication with chamber 17 via a passageway 20 through member 3 and a non-return valve 21; and chamber 18 is in communication with chamber 17 via a passageway 20 through member 3 and a non-return valve 21. Chambers 17 and 17 are in communication with a high pressure (HP) supply output via non-return valves 22 and 22 respectively.

(7) Reference numerals 23 and 23 denote seals via which pistons 4 and 4 slide in cylinders 2 and 2 respectively and reference numerals 24 denote seals against which member 5 slides in section 3.

(8) Reference numeral 25 denotes electronic operating means for alternately energising and de-energising the solenoids 8 and 8, one after the other. The electronic operator 25 could be provided by a multivibrator module attached to or located close to the intensifier for other than subsea well usage. Alternatively, for example, in the case of use of the intensifier in connection with a subsea well, the function of electronic operator 25 could be provided by a subsea electronics module (SEM) of the well control system.

(9) When the solenoid 8 is energised by electronic operator 25, low pressure hydraulic fluid is switched by the pilot valve 10 into the chamber 18, whereby the pressure of the fluid acts on the face 6 of the piston 4, causing the latter to move to the right in FIG. 1 and force the fluid in the chamber 17, through the non-return valve 22 as a high pressure output. This output is at a higher pressure than the low pressure input because the surface area of the piston face 7 is less than the surface area of the piston face 6. The non-return valve 21 allows fluid transfer into the chamber 17, fluid in chamber 18 passing via passageway 19 and port 11 of pilot valve 10 to be vented to the return since solenoid 8 is de-energised. It is to be noted that, because of passageway 20 and non-return valve 21, when low pressure hydraulic fluid is applied to face 6 of piston 4, the pressure of that fluid will also be present at the face 7 of piston 4, thereby increasing the sum of areas exposed to low pressure fluid. Thereafter, de-energising of solenoid 8 and energising of solenoid 8 by electronic operator 25 causes the piston 4 to return to the left, with the same form of pumping action as described above to the high pressure output via valve 22 being effected as a result of the action of piston 4. Thus, the arrangement of pistons 4 and 4 is double-acting, providing a continuous pumping action.

(10) FIG. 2 shows an alternative form of intensifier to that of FIG. 1 in that, for the sake of ease of manufacture, passageway 20 and valve 21 and passageway 20 and valve 21 are external of pistons 4 and 4 and cylinder member 3. Otherwise, its arrangement and manner of operation are identical to the intensifier of FIG. 1.

(11) Advantages of embodiments of the present invention include the pressure intensifier of this invention being more reliable, cheaper to manufacture and does not have the fluid leakage problems of current designs.

(12) This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.