A method for determining a pressure profile in a subterranean formation is described. The method includes drilling a wellbore in the subterranean formation; lowering a logging tool into the wellbore to measure resistivity values as a function of depth along the wellbore; identifying a plurality of porous zones from the wellbore based on petrophysical logs; converting the measured resistivity values to an amount of total dissolved solids for each of the plurality of identified porous zones; converting the amount of total dissolved solids to a pore fluid density; calculating a pressure based on a sum of the pore fluid densities derived along a length of the well; and generating a depth-based pressure profile.

Various embodiments include a capacitive pressure transducer for measuring the pressure of a medium adjacent to the transducer comprising: a measurement diaphragm including a first surface in contact with the medium and a second surface facing away from the medium; a measurement electrode integrated with the measurement diaphragm; a base body arranged opposite the second surface, the base body comprising a counter electrode forming a measurement capacitance with the measurement electrode; and an electrically insulating chamber bounded by the base body and the measurement diaphragm. The counter electrode is in contact with the electrically insulating chamber. At least one of the measurement electrode or the counter electrode comprises a meandering pattern layer in direct contact with the electrically insulating chamber.

A pressure sensor includes a connection portion provided with a screw portion configured to fix the pressure sensor to a combustion chamber of a vehicle engine; a hollow liquid-enclosing container fixed to one end of the connection portion; a pressure transmission fluid enclosed inside the liquid-enclosing container; a diaphragm fixed to one end of the liquid-enclosing container and elastically deformed when receiving pressure to transmit the pressure to the pressure transmission fluid; a pressure detection element fixed to the other end of the liquid-enclosing container and detecting the pressure transmitted to the pressure transmission fluid and converts the detected pressure into an electric signal; and a heat-dissipating rod provided inside the liquid-enclosing container. The connection portion and the liquid-enclosing container, and the connection portion and the diaphragm are mechanically connected to each other by welding or the like.

An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensing head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.

A pressure sensing apparatus which utilizes an electrolytic droplet retained between a first and second sensing electrode within a housing. Contact between the electrolyte droplet and the electrodes form electric double layers (EDL) having interfacial EDL capacitance proportional to interface contact area which varies in response to mechanical pressure applied to deform exterior portions of the housing. The electrolyte contains a sufficient percentage of glycerol to prevent evaporative effects. Preferably, the sensing electrodes are modified with depressions, hydrophilic and/or hydrophobic portions to increase central anchoring of the electrolyte droplet within the housing. The inventive pressure sensor provides high sensitivity and resolution which is beneficial to numerous applications, and is particularly well-suited for medical sensing applications.

A fluid 10 is contained within a chamber 12. The chamber wall 14 has an inner surface 16 exposed to the fluid 10 and an outer surface 18 separated from the inner surface 18 by the material 20 of the wall 14. Ultrasound 22 is introduced into the material 20. Measurement of the time of flight of the ultrasound 22 through the body 20 allows a measurement to be made of the pressure of the fluid 10.

An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensing head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.

A pressure sensing apparatus which utilizes an electrolytic droplet retained between a first and second sensing electrode within a housing. Contact between the electrolyte droplet and the electrodes form electric double layers (EDL) having interfacial EDL capacitance proportional to interface contact area which varies in response to mechanical pressure applied to deform exterior portions of the housing. The electrolyte contains a sufficient percentage of glycerol to prevent evaporative effects. Preferably, the sensing electrodes are modified with depressions, hydrophilic and/or hydrophobic portions to increase central anchoring of the electrolyte droplet within the housing. The inventive pressure sensor provides high sensitivity and resolution which is beneficial to numerous applications, and is particularly well-suited for medical sensing applications.

An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensor head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.

In some implementations a semiconductor die comprises a semiconductor chip. The semiconductor chip comprises a piezoresistive pressure sensor element and at least one capacitive acceleration sensor element. The piezoresistive pressure sensor element is arranged to the side of the capacitive acceleration sensor element. In some implementations, a method for producing a semiconductor die includes applying an insulation layer to the semiconductor wafer. A section of the monocrystalline cover layer may be exposed by structuring the insulation layer. A semiconductor layer having a monocrystalline section and a polycrystalline section may be generated by deposition of a semiconductor material.