Abstract: An in situ method for repairing a base flange of a wellhead. At least one layer of a polymerizable composite material is applied to a damaged surface, an elastic seal is placed on the layer of composite material, and a reinforcing collar is pressed against the seal on the surface of the flange covered with the composite material. An arrangement of an in situ repair of a base flange of a wellhead includes at least one layer of a polymerized composite material on a damaged surface, an elastic seal on the composite material, and a reinforcing collar pressing the seal against the damaged surface.

Abstract: The bleeder comprises a hydraulically remotely controlled bleed valve (150) and device for guaranteeing that during bleeding, the gas is exhausted away from the well head zone. The bleed valve (150) is advantageously situated at the top end of the pressure lock and has a valve body (9) defining a main channel (17) of sufficient cross-section to pass to wireline tool. The bleed valve also has a gas exhaust lateral orifice (16) for being put selectively into communication with a first transverse channel (15) which opens out into the main channel (17) by a closure member constituted by a valve seat and a valve member formed at one end of a piston (5). A second transverse channel (14) puts the main channel (17) into communication with a rear face of the piston (5), where the rear face has a greater section than its valve-forming front face.

Abstract: The invention relates to an isolation chamber valve. The isolation chamber valve of the invention includes, for connecting its inlet passage and its outlet passage, a by-pass circuit of small section comprising at least a flap the opening and closing of which can be controlled as required. This isolation chamber valve is used in particular in the operation of shafts for deposits or the storage of gas or other fluids under pressure.