Abstract: A method for downhole flow measurement comprises installing a fibre optical distributed temperature sensor (DTS) system along at least part of the length of an inflow region of the well and using the sensor to measure fluctuations of the temperature of fluids flowing from the formation into the well and the velocity at which said natural fluctuations migrate in downstream direction through the well. The measured temperature variations may be low frequency temperature fluctuations of between 0.1 and 0.5 Degrees Celsius, which gradually die out downstream of the inflow region(s) of the well.

Abstract: A method of installing a double ended distributed sensing optical fiber assembly within a guide conduit. The optical fiber sensing assembly has a first elongate section with a first proximal end and a first distal end, and a second elongate section with a second proximal end and a second distal end. The method includes providing a nose section having an outer width less than about 1 cm, which interconnects the first proximal end to the second proximal end such that light transmitted along the length of the first elongate section is transmitted via the nose section into the second elongate section, inserting the nose section into the guide conduit such that the nose section moves through the guide conduit ahead of the first elongate section and the second elongate section; and connecting the first distal end and the second distal end to a light transmission and receiving unit.

Abstract: A method and system are disclosed for measuring pressure and other physical data such as the temperature, elongation, torsion and bending at any point along the length of an elongate carrier tube by means of one or more coiled optical fibers that are embedded in the wall the tube such that deformation of the carrier tube induces strain in each optical fiber. In use a pulsed laser light source transmits a sequence of light pulses of a selected wavelength from an upstream end of each fiber into a coiled substantially uniform light guide channel provided by the optical fiber and a light sensor assembly detects any shift in wavelength of the light pulses backscattered from various locations along the length of the light guide channel. A signal processing assembly then calculates a strain pattern along the length of the fiber, and a pressure difference between the interior and exterior of the tube, at various locations along the length of the carrier tube.

Abstract: A thermoacoustic power generator for generating electricity within or in the vicinity of a gas transportation conduit, such as a production tubing in a gas production well, having an acoustic resonance cavity having an inlet formed by an orifice in the wall of the conduit or of equipment arranged within the conduit to create a standing acoustic wave in the resonance cavity in response to the gas flow in the conduit, and a permeable body in the resonance cavity in which body cold and/or hot spots are formed as a result of adiabatic expansion or compression. A thermoelectric device, such as a Peltier element, is connected to the cold and/or hot spots formed in the permeable body to generate electrical power in response to the resulting temperature decrease or increase of the permeable body, which may exceed 50° C.