Abstract: The invention provides a method of separating at least two production zones in a well (P) using the following method and apparatus. The method is a method of making a sealing ring (18) in situ in an annular space (5) lying between a well (P) and casing (T) in the well, with the sealing ring being made adjacent to a production zone in the well, and with the method comprising the following stages:the annular space (5) to be occupied by the sealing ring (18) is delimited; anda sealing substance (11) is injected into the annular space.The apparatus comprises two confinement membranes (2--2) for sealing off the annular space (5); andseparator membrane (8, 13) for separating the substance to be injected (11) from the fluids that normally exist between the well (P) and the casing (T), said separator membrane also serving to eject said fluids from said space (5). The invention is applicable to the drilling industry, and in particular to the oil industry, and the like.

Abstract: A geomechanical probe for a drilling well comprises a logging box located between two inflatable preventers and including a plurality of tracers movable radially and urged outwards by springs for engaging the well wall. The tracers are mounted on pistons which are received in cylinders and urged radially inwards by springs for retracting the tracers, the pistons being driven outwardly to displace the tracers into working positions abutting the well wall by supply of actuating fluid to the cylinders. The position of the tracers is determined by differential transformers having cores fixed for radial movement with respective tracers. The preventers are inflated with pressurized fluid which is supplied thereto along passages in the probe which also supply pressurized fluid to the well space between the preventers to act upon the well wall.

Abstract: In a hydrocarbon production well in which the effluent is activated by an activation pump removably installed in a production pipe in the well, a safety valve is removably mounted in the production pipe below the activation pump. The safety valve comprises, in a lower part of the valve body, a foot valve and thereabove an obturator which is moved to its open position by an operating member which is provided with a piston slideably mounted in the valve body and separating first and second chambers. The first chamber is pressurized to open the valve, and the second chamber, which acts in opposition to the first chamber, is in communication with the bottom of the well below the foot valve, and is thus isolated from the interior of the safety valve when the foot valve is closed.

Abstract: In a hydrocarbon production well in which effluent is activated by an activation pump installed in a production pipe in the well, a safety valve is disposed in the production pipe beneath the pump and is controlled for opening purposes by a control chamber which is provided with pressurized fluid present at the level of the pump. To this end an annular passage is provided inside the production pipe along a wall connecting the pump to the valve, the annular passage communicating at its ends with means for bringing it into communication with the pressurized fluid present at the level of the pump and the control chamber respectively.

Abstract: In a production well-head for an underwater oil well the suspension head of the innermost tubing, which has a frusto conical surface on which the production tube suspension member seats, has a duct leading from the enclosed space between the innermost tubing and the tubing adjacent thereto, to the interior of the innermost tubing, and a duct communicating therewith is provided in the suspension member.

Abstract: In the automatic positioning of one submerged unit relative to another submerged unit without the use of guide lines, guiding structures associated with the units are brought into contact and the units are relatively orientated before the units are brought into contact.