Abstract: The preferred embodiments are directed to the oil-producing industry and can be used in operating multi-reservoir wells. A method for the determination of hydrodynamic parameters for each flowing reservoir that includes reaching at least one well operating mode with fluid flow through both the wellbore and one or more reservoirs, measuring at least one parameter that characterises fluid flow, recording its acoustic noise logging data, calculating noise power using reservoir fluid flow noise logging data, and subsequent multi-phase hydrodynamic modelling to determine hydrodynamic parameters for each identified reservoir.

Abstract: An apparatus for estimating a property in a borehole penetrating the earth, the apparatus having: a carrier configured to be disposed in the borehole; and an acoustic transducer disposed at the carrier and configured to at least one of transmit and receive an acoustic wave used to estimate the property, the acoustic transducer comprising an acoustic diaphragm; wherein the acoustic diaphragm includes a surface in communication with a plurality of structural members configured to increase the rigidity of the surface, the surface being configured to interface with a medium that propagates the acoustic wave.

Abstract: A method of method of determining relative contributions of two or more producing subterranean sources to a total flow is described using the steps of selecting a subset from a set of identifiable components in the total flow and using the subset to determine the relative contributions of two or more producing subterranean sources, wherein the subset is selected based on the sensitivity of the determination step to errors in the measurement of concentrations of said identifiable components.