Patent EA-002217-B1 (EA)
Title: A device and method for regulating fluid flow in a well
Inventor: GUNNARSSON BENGT
IPC: E21B34/10
Filed: 1999-06-01
Abstract: 1. A device for mutually independent control of regulating devices (1-6) for controlling fluid flow between a hydrocarbon reservoir (50) and a well (51) which extends from a starting area (52) to the hydrocarbon reservoir, wherein the regulating devices (1-6) are provided in the well (51) in the hydrocarbon reservoir (50), where each regulating device (1) comprises a flow controller (54) with a regulating element (55) which is movable between regulating positions for the fluid flow, a hydraulic actuator (56) with an actuating element (57) which is connected to the regulating element (55) for actuating the flow controller (54), and control valves (20-25) for controlling the flow of hydraulic liquid between the actuator (56) and hydraulic pipes (11-14) which extend from the well's starting area (52) to the hydrocarbon reservoir (50), characterized in that the actuator (56) is flow-relatedly arranged via the ports (15, 16) in series with at least two associated control valves (20-25) in a hydraulic path (18,19) between two hydraulic pipes (11,14), that the control valves (20-25) are of the type which open and close for the flow of hydraulic liquid in the presence and absence respectively of at least an opening pressure on a control port (30-35), that the control port (30) on at least one (20) of the control valves is connected to one of the hydraulic pipes (11 or 14) and that the control port (31) on at least one (21) of the other control valves is connected to the other hydraulic pipe (14 or 11), and that the combination of two hydraulic pipes (11-14) which are connected to an actuator (56) is different for independently controllable regulating devices (1-6). 2. A device according to claim 1, characterized in that there is flow-relatedly arranged at least one (20) of the said control valves on each side of each actuator (56). 3. A device according to claim 1 or 2, characterized in that there is flow-relatedly arranged two (20,21) of the said control valves on each side of each actuator, and that the two control valves have control ports (30,31) each of which is connected to a respective hydraulic pipe (11,14). 4. A device according to claim 3, characterized in that two control valves which are flow-relatedly located on each side of the actuator and which have control ports which are connected to the same hydraulic pipe (14) are composed of a control valve unit (24) with a common control port (34). 5. A device according to any one of the preceding claims, characterized in that the actuator (56) is provided with at least one throughgoing passage (74,75,85) which is open for throughput of hydraulic liquid when the actuating element (57) is located in regulating positions, and which is closed when the actuating element (57) is located outside the regulating positions. 6. A device according to any one of the preceding claims, characterized in that between each actuator (56) and each of the hydraulic pipes (11,14) to which the actuator is connected there is flow-relatedly arranged a self-controlled dosing valve (77) in series with the control valves (20-25), and that the dosing valve (77) is of the type in which an internal volume (79) is filled with inflowing liquid on pressurisation of an inlet (78), whereupon the inflow stops until the inlet (78) is depressurised, and which by means of repeated pressurisation of the inlet (78) delivers the liquid of the internal volume (79). 7. A method for mutually independent control of regulating devices (1-6) for controlling the fluid flow between a hydrocarbon reservoir (50) and a well (51) which extends from a starting area (52) to the hydrocarbon reservoir (50), by means of a device according to one of the preceding claims, characterized in that the two hydraulic pipes (11,14) which are connected to the control valves (20-25) for the regulating device's actuator (56) are pressurised with hydraulic liquid to at least the opening pressure of the associated control valves (20-25), whereby the associated control valves (2025) open for the flow of hydraulic liquid between the two hydraulic pipes (11,14) and the actuator (56), and that between the two hydraulic pipes (11,14) there is established a pressure differential which is sufficiently great to move the actuating element (57), whereby the actuator (56) actuates the flow controller (54). 8. A method according to claim 7, when using a device according to claim 5, characterized in that the pressure in the two hydraulic pipes (11,14) and the hydraulic liquid's flow rate are monitored during the actuation, and that, since the throughgoing passages (74,75,85) are opened when the actuating element (57) is located in regulating positions, the actuating element's (57) and thereby the regulating element's (55) regulating positions are detected as a drop in the pressure of the hydraulic liquid and/or an increase in the hydraulic liquid's flow rate. 9. A method according to claim 7, characterized in that the pressure in the two hydraulic pipes (11,14) and the throughput volume of hydraulic liquid between the two hydraulic pipes (11,14) are monitored during the actuation, and that the regulating element's (55) regulating positions are calculated on the basis of the actuator's (56) internal hydraulic volume and throughput volume of hydraulic liquid during actuation. 10. A method according to claim 10, when using a device according to claim 6, characterized in that the throughput volume of hydraulic liquid is calculated on the basis of the dosing valve's (77) internal volume (79) and the number of pressurisations of the inlet (78).