Abstract: A method utilized in borehole logging, such as in surveying or exploration relating to a subsurface formation. The method includes deploying a logging instrument that includes a pressure sensor into a borehole drilled into the formation. The method includes the steps of obtaining a first pressure value at a first depth in the borehole, obtaining at least one further pressure value subsequent to the first pressure value during withdrawing or advancing the logging instrument in the borehole, and determining one or more characteristics of the subsurface formation, utilizing at least one of the further pressure values, or a change in pressure (??) between the first pressure value and a said further pressure value or values, or a change in pressure (??) between a said further pressure value and another said further pressure value, or a combination of two or more of such values.

Abstract: A method utilised in borehole logging, such as in surveying or exploration relating to a subsurface formation. The method includes deploying a logging instrument that includes a pressure sensor into a borehole drilled into the formation. The method includes the steps of obtaining a first pressure value at a first depth in the borehole, obtaining at least one further pressure value subsequent to the first pressure value during withdrawing or advancing the logging instrument in the borehole, and determining one or more characteristics of the subsurface formation, utilising at least one of the further pressure values, or a change in pressure (??) between the first pressure value and a said further pressure value or values, or a change in pressure (??) between a said further pressure value and another said further pressure value, or a combination of two or more of such values.

Abstract: A method utilized in borehole logging, such as in surveying or exploration relating to a subsurface formation. The method includes deploying a logging instrument that includes a pressure sensor into a borehole drilled into the formation. The method includes the steps of obtaining a first pressure value at a first depth in the borehole, obtaining at least one further pressure value subsequent to the first pressure value during withdrawing or advancing the logging instrument in the borehole, and determining one or more characteristics of the subsurface formation, utilizing at least one of the further pressure values, or a change in pressure (??) between the first pressure value and a said further pressure value or values, or a change in pressure (??) between a said further pressure value and another said further pressure value, or a combination of two or more of such values.

Abstract: A method utilised in borehole logging, such as in surveying or exploration relating to a subsurface formation. The method includes deploying a logging instrument that includes a pressure sensor into a borehole drilled into the formation. The method includes the steps of obtaining a first pressure value at a first depth in the borehole, obtaining at least one further pressure value subsequent to the first pressure value during withdrawing or advancing the logging instrument in the borehole, and determining one or more characteristics of the subsurface formation, utilising at least one of the further pressure values, or a change in pressure (??) between the first pressure value and a said further pressure value or values, or a change in pressure (??) between a said further pressure value and another said further pressure value, or a combination of two or more of such values.

Abstract: An array of induction magnetometers for use in airborne transient electromagnetic (ATEM) geophysical exploration is disclosed, having similar weight and external dimensions of prior art induction magnetometers but with improved signal strength, signal-to-noise ratio, higher frequency, self-resonance and bandwidth, and providing accurate and well monitored calibration.