Abstract: A method and system for recovering oil from a subterranean reservoir. The method includes delivering an injection gas through an injection flow path into a plurality of regions of the reservoir via a plurality of outflow devices arranged along the injection flow path, producing oil from a plurality of regions of the subterranean reservoir via a production flow path with a plurality of inflow devices arranged along the production flow path, and restricting flow of the injection gas into the production flow path from the reservoir. The restricting of the flow in injection gas may be by choking the flow of the injection gas through at least one of the plurality of inflow devices such that the residence time of the injection gas within the subterranean reservoir is increased.

Abstract: A method and system for recovering oil from a subterranean reservoir, the method comprising: delivering an injection gas through an injection flow path into a plurality of regions of the reservoir via a plurality of outflow devices arranged along the injection flow path; producing oil from a plurality of regions of the subterranean reservoir via a production flow path with a plurality of inflow devices arranged along the production flow path; and restricting flow of the injection gas into the production flow path from the reservoir by choking the flow of the injection gas through at least one of the plurality of inflow devices such that the residence time of the injection gas within the subterranean reservoir is increased,

Abstract: A downhole control system for actuating hydraulically controlled devices positioned in a well. The system includes a first set of N hydraulically controlled devices positioned in the well and a second set of at least one hydraulically controlled device positioned in the well. A common control line is ported to a first side of each of the hydraulically controlled devices in the first set. N control lines are each ported to a second side of one of the hydraulically controlled devices in the first set. A first control line of the N control lines is ported to a first side of a first hydraulically controlled device of the second set and a second control line of the N control lines is ported to a second side of the first hydraulically controlled device of the second set, such that N+1 control lines are operable to actuate N+1 hydraulically controlled devices.

Abstract: A downhole control system for actuating hydraulically controlled devices positioned in a well. The system includes a first set of N hydraulically controlled devices positioned in the well and a second set of at least one hydraulically controlled device positioned in the well. A common control line is ported to a first side of each of the hydraulically controlled devices in the first set. N control lines are each ported to a second side of one of the hydraulically controlled devices in the first set. A first control line of the N control lines is ported to a first side of a first hydraulically controlled device of the second set and a second control line of the N control lines is ported to a second side of the first hydraulically controlled device of the second set, such that N+1 control lines are operable to actuate N+1 hydraulically controlled devices.

Abstract: The whipstock assembly comprises an assembly casing (9) with preformed windows connected to production casing (7); a landing tube (21) is located within assembly casing (9) for receiving whipstock shaft; a key is located within tube (21) for cooperation with J-slot on whipstock shaft. The whipstock consists of upper (49) and lower (55) portion which are fixed against relative rotation by splines. The assembly casing (9) with landing tube (21) is positioned in the borehole using a gyro survey tool for correct orientation of the windows. After a first side hole has been drilled, upper portion (49) is raised and rotated to place wedge surface (51) for drilling a second side hole. Tube (21) is initially closed by a cap containing a marking fluid; after the cap has been drilled out the marking fluid indicates the removal of the cap. In a second embodiment two vertically spaced side holes are drilled.