Abstract: A wireless downhole information transfer system is presented, which is adapted to operate in wells (well bores), and in particular in wells for the Oil & Natural Gas and Geothermal Industry. The information transfer system comprises an elongated tubing (completion) having several tubing sections comprising a first and a last end tubing section, an information signal generator placed at or near the first tubing section of the elongated tubing. The information signal generator is designed as a torsional wave generator for transmission of a torsional wave information signal along the elongated tubing, and an information signal receiver arranged at or near the last tubing section of the elongated tubing, wherein the elongated tubing between the signal generator and the signal receiver constitutes the carrier for transmission of the information signal between the signal generator and the signal receiver.

Abstract: A downhole tool for investigating an outside fluid flow being adapted to operate in a well bore is presented. The downhole tool comprises a housing surrounded by an outside fluid and at least a first wave generator device. The first wave generator device preferably comprises a directional sound generator, for coupling waves into the surrounding outside fluid. The waves therein are scattered, for example, reflected, at inhomogeneities in the outside fluid, for example particles, scatterers and/or water in oil, thereby generating reflections. Said reflections are measured with a receiver device for receiving said reflections, and are evaluated using an evaluation device for determining first positions of said inhomogeneities in the outside fluid by evaluating said reflections, wherein the evaluation device is adapted to determine the outside fluid flow.

Abstract: The invention relates to a method and a device for quantitive determination of a number and size of particulate components contained in a medium flowing along a flow channel. Ultrasonic waves are coupled into the flowing medium, which are reflected at least partially by the particulate components and reflected ultrasonic wave portions which are detected in a ultrasonic time signals, on which the quantitive determination is based. Amplitude values associated with the individual ultrasonic time signals, are detected which are each greater than an amplitude threshold value established for each ultrasonic time signal: The detected amplitude values are assigned to values describing the size and the number of the particulate components.

Abstract: The invention relates to a method and a device for quantitively determining a number and size of particulate components contained in a medium flowing along a flow channel. Ultrasonic waves are coupled into the flowing medium, which are reflected at least partially by the particulate components and reflected ultrasonic wave portions which are detected in a ultrasonic time signals, on which the quantitive determination is based.

Abstract: An ultrasonic displacement measurement system for hydraulic accumulators (3) has a movable separating element (5) separating two media chambers (9, 11) from each other in a media-tight manner within a housing (7). One media chamber (9) holds a compressible fluid or an incompressible fluid. The other media chamber (11) holds a compressible working gas. The particular position of the movable separating element (5) within the housing (7) can be detected by an ultrasonic sensor (13) that performs the position detection of the separating element (5) on the side of the media chamber (11) having the compressible fluid. A method for ultrasonic displacement measurement uses that system.

Abstract: A tool for detecting leaks in downhole pipe comprises wave generator devices (30, 40) for coupling ultrasound waves into the surrounding fluid. The waves are scattered, e.g. reflected, at inhomogeneities (60) in the fluid, for example particles, scatterers and/or water in oil, thereby generating reflections (70) which are measured with a receiver device (25) and evaluated for determining the positions of the inhomogeneities in the fluid in order to detect e.g. crossflows (15) generated by leakage (65).

Abstract: The invention relates to an ultrasonic displacement measurement system (1), which in particular can be used for hydraulic accumulators (3) having at least one movable separating element (5), which separates two media chambers (9, 11) from each other preferably in a media-tight manner within a housing (7), wherein the one media chamber (9) holds a compressible fluid or an incompressible fluid and the other media chamber (11) holds a compressible fluid, in particular in the form of a working gas, wherein the particular position of the movable separating element (5) within the housing (7) can be detected by means of at least one ultrasonic sensor (13), is characterized in that the at least one ultrasonic sensor (13) performs the position detection of the separating element (5) on the side of the other media chamber (11) having the compressible fluid. The invention further relates to a method for ultrasonic displacement measurement by means of such a system.

Abstract: An acoustic transducer, especially an air transducer, including a piezoceramic disk (10). The object of the invention is to provide an improved transducer of this type for more efficiently converting electromagnetic waves into mechanical waves and vice versa. To this end, a combination of a piezoceramic disk (10) and a membrane (8) is provided, the membrane being configured as a monomorphic flexural resonator and being composed of an epoxy-hollow glass sphere mixture or of a material which is similar in terms of its acoustic properties. The planar vibration mode (4) in the piezoceramic is converted into a thickness vibration (6) using Poisson's ratio. After the conversion, this thickness vibration is then adapted to the propagation medium, especially air, by a coupling layer having a low acoustic impedance.