A method and device for taking measurements and/or carrying out interventions in a well comprising a first zone wherein hydraulic compression including for providing hydraulic fracturing is achieved and a second zone wherein measurements and/or interventions are carried out, said compression zone communicating through a casing to hydraulic pressure means, the lower end of the casing comprising an assembly of one or the plurality of measuring instruments connected to the surface via cable placed inside the casing and mechanically isolated from the casing by an elastic link. In the method, at a point in the casing adjacent to the fracturing zone, any fracturing fluid flow coming from or going to said fracturing zone is controlled by a control element actuated at least partially by the cable from the surface, the control element being situated at a level higher than the assembly. The device includes means which control the fluid circulation between the casing and the compression zone and the cable is adapted to control the means from the surface.