Abstract: An apparatus and corresponding method for determining component flow rates of a multiphase fluid in a conduit, the fluid consisting of at least three known components, the method including the steps of: measuring at each of two different positions along the conduit at least four mixture quantities, typically the sound speed, the flow velocity of the multiphase fluid, the pressure and the temperature; providing a speed of sound in each of the components at the measured pressures and temperatures; providing a trial value for each of either the component flow rates or the phase fractions; using a predetermined model to calculate values for the measured mixture quantities based on the trial values for each of either the component flow rates or the phase fractions; using a predetermined error function to determine an error value; and using a predetermined optimizing algorithm to determine whether the calculated values are acceptable, and, if they are not, to provide a new trial value for each of either the compone

Abstract: A multiphase flow meter distributed system is disclosed that is capable of measuring phase flow rates of a multiphase fluid. The distributed system includes at least one flow meter disposed along the pipe, an additional sensor disposed along the pipe spatially removed from the flow meter, and a multiphase flow model that receives flow related parameters from the flow meter and the additional sensor to calculate the phase flow rates. The flow meter provides parameters such as pressure, temperature, fluid sound speed and/or velocity of the fluid, and the additional sensor provides a parameter indicative of pressure and or temperature of the fluid. Depending on production needs and the reservoir dimensions, the distributed system may utilize a plurality of flow meters disposed at several locations along the pipe and may further include a plurality of additional sensors as well. The distributed system preferably uses fiber optic sensors with bragg gratings.

Abstract: A multiphase flow meter is presented based on distributed sensors that provide data pertaining to temperature, pressure, phase fraction, speed of sound, and bulk velocity. The data is provided to a model that calculates the multiphase flow rates. The sensors are comprised of various combinations of temperature and pressure sensors combined with speed of sound and/or bulk velocity sensors and are distributed at various axial positions along an oil production pipe. In one embodiment the sensors comprise Bragg grating based optical sensors.

Abstract: A multiphase flow meter distributed system is disclosed that is capable of measuring phase flow rates of a multiphase fluid. The distributed system includes at least one flow meter disposed along the pipe, an additional sensor disposed along the pipe spatially removed from the flow meter, and a multiphase flow model that receives flow related parameters from the flow meter and the additional sensor to calculate the phase flow rates. The flow meter provides parameters such as pressure, temperature, fluid sound speed and/or velocity of the fluid, and the additional sensor provides a parameter indicative of pressure and or temperature of the fluid. Depending on production needs and the reservoir dimensions, the distributed system may utilize a plurality of flow meters disposed at several locations along the pipe and may further include a plurality of additional sensors as well. The distributed system preferably uses fiber optic sensors with bragg gratings.

Abstract: An apparatus and corresponding method for determining component flow rates of a multiphase fluid in a conduit, the fluid consisting of at least three known components, the method including the steps of: measuring at each of two different positions along the conduit at least four mixture quantities, typically the sound speed, the flow velocity of the multiphase fluid, the pressure and the temperature; providing a speed of sound in each of the components at the measured pressures and temperatures; providing a trial value for each of either the component flow rates or the phase fractions; using a predetermined model to calculate values for the measured mixture quantities based on the trial values for each of either the component flow rates or the phase fractions; using a predetermined error function to determine an error value; and using a predetermined optimizing algorithm to determine whether the calculated values are acceptable, and, if they are not, to provide a new trial value for each of either the compone

Abstract: A DC pressure and temperature sensor system for sensing and measuring the DC pressure and temperature of a production fluid (such as oil, gas and water mixtures) in tubing, such as tubing used to extract production fluid from a drilled site. The sensor system includes at least one fluid sensor, but sometimes two. Only one is needed if either the DC pressure or temperature of the production fluid (but not both) is provided by an independent measurement. In general, though, the sensor system includes: a first and second fluid sensor, the first using a first sensing material, and the second using a second sensing material in which sound travels at a rate that depends on the DC pressure and temperature of the second sensing material in a measurably different way than for the first sensing material. Each sensing material is coupled to the production fluid, preferably via a thin-walled membrane, so as to be at a DC pressure and temperature that is, preferably, the same as for the production fluid.

Abstract: A device in the form of a cardiac pacemaker for treating a malfunctioning heart, in which the intrinsic heart rate information is combined with secondary sensor variance information to select an appropriate therapy for the patient. The cardiac pacemaker has operational capability in the sleep mode and includes a hysteresis function. The hysteresis function is disabled during operation in the sleep mode and a pacing therapy is selected based upon the intrinsic heart rate and sleep mode operation.