Abstract: In a hydrocarbon production well in which the effluent is activated by an activation pump installed in a production pipe, a safety valve is disposed in the production pipe below the pump, the safety valve being operated by lowering of an operating member by a controlling device. The controlling device comprises a piston and cylinder system, and connection means connecting the piston to the operating member during the downward movement of the piston. The cylinder and piston system is provided at the level of the pump, and is advantageously constituted by the production pipe and pump respectively, so that pressurized fluid present at the level of the pump will cause downward movement of the piston.

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.