Abstract: A well tool (10) for use in a well pipe comprises a housing (11) and a pulse generator (14) provided within the housing (11). The pulse generator (14) comprises an inductor (Ls), and a power supply device (HV, c) for supplying electrical power to the inductor (L) and thereby providing that an electromagnetic pulse is generated, in such a way that the electromagnetic pulse is providing physical vibrations in the well pipe. A cross sectional gap area (Agap) of an annular gap between a median of the inductor (Ls) and an inner surface of the well pipe is substantially equal to an inner cross sectional area (Ainner) of the inductor (Ls) up to the median diameter (d) of the inductor.

Abstract: A method has been disclosed for determining a position of a water/cement boundary in an annular area between two concentric pipes in a hydrocarbon well. The method comprises the steps of running a well tool (10) into a central pipe of the well, where the well tool (10) comprises a tool housing (11), a pulse generator (14) and a signal recorder (16) provided within the housing (11); generating an electromagnetic pulse by means of the pulse generator, thereby providing physical vibrations in the central pipe of the well; recording reflected acoustic signals from the well by means of the signal recorder (16); repeating the generating and recording steps for different vertical positions of the pulse generator in the well; organizing the recorded signals in a two-dimensional representation; filtering the organized recorded signals in order to identify, in the two-dimensional representation, a hyperbola (B); and providing an apex of the hyperbola (B) as the determined position of the water/cement boundary.

Abstract: The invention relates to a method and apparatus for determining the nature of a material in a cavity between one inner metal wall and one outer metal wall provided outside the inner metal wall. First a tool is located on the inside of the inner metal wall, where the tool comprises a pulse generator and a signal recorder. An electromagnetic short duration pulse is generated by means of the pulse generator, the pulse inducing mechanical vibrations in the walls. Data representing the reflections of the mechanical vibrations from said cavity is recorded by means of the signal recorder. The recorded data is analyzed to determine the nature of the material in the cavity.

Abstract: A well tool (10) for use in a well pipe comprises a housing (11) and a pulse generator (14) provided within the housing (11). The pulse generator (14) comprises an inductor (Ls), and a power supply device (HV, c) for supplying electrical power to the inductor (L) and thereby providing that an electromagnetic pulse is generated, in such a way that the electromagnetic pulse is providing physical vibrations in the well pipe. A cross sectional gap area (Agap) of an annular gap between a median of the inductor (Ls) and an inner surface of the well pipe is substantially equal to an inner cross sectional area (Ainner) of the inductor (Ls) up to the median diameter (d) of the inductor.

Abstract: A method has been disclosed for determining a position of a water/cement boundary in an annular area between two concentric pipes in a hydrocarbon well. The method comprises the steps of running a well tool (10) into a central pipe of the well, where the well tool (10) comprises a tool housing (11), a pulse generator (14) and a signal recorder (16) provided within the housing (11); generating an electromagnetic pulse by means of the pulse generator, thereby providing physical vibrations in the central pipe of the well; recording reflected acoustic signals from the well by means of the signal recorder (16); repeating the generating and recording steps for different vertical positions of the pulse generator in the well; organizing the recorded signals in a two-dimensional representation; filtering the organized recorded signals in order to identify, in the two-dimensional representation, a hyperbola (B); and providing an apex of the hyperbola (B) as the determined position of the water/cement boundary.

Abstract: The invention relates to a method and apparatus for determining the nature of a material in a cavity between one inner metal wall and one outer metal wall provided outside the inner metal wall. First a tool is located on the inside of the inner metal wall, where the tool comprises a pulse generator and a signal recorder. An electromagnetic short duration pulse is generated by means of the pulse generator, the pulse inducing mechanical vibrations in the walls. Data representing the reflections of the mechanical vibrations from said cavity is recorded by means of the signal recorder. The recorded data is analyzed to determine the nature of the material in the cavity.