Abstract: A bottomhole assembly is provided with a cathode. The cathode produces a static field in the earth formation and by the electroosmotic effect, inhibits the invasion of the formation by borehole fluids and reduces formation damage. The cathode also results in improved estimates of formation permeability using flow tests. A cathode on a wireline string may be used to reduce water saturation in an invaded zone near a borehole.

Abstract: A bottomhole assembly is provided with a cathode. The cathode produces a static field in the earth formation and by the electroosmotic effect, inhibits the invasion of the formation by borehole fluids and reduces formation damage. The cathode also results in improved estimates of formation permeability using flow tests. A cathode on a wireline string may be used to reduce water saturation in an invaded zone near a borehole.

Abstract: Resistivity measurements are made at a plurality of frequencies. An asymptotic high-frequency limit is determined and the electrical efficiency is estimated as a ratio of the high frequency resistivity limit to the low frequency resistivity. From the electrical efficiency, petrophysical parameters of a rock such as porosity and water saturation can be estimated.

Abstract: Resistivity measurements are made at a plurality of frequencies. An asymptotic high-frequency limit is determined and the electrical efficiency is estimated as a ratio of the high frequency resistivity limit to the low frequency resistivity. From the electrical efficiency, petrophysical parameters of a rock such as porosity and water saturation can be estimated.

Abstract: Resistivity measurements are made at a plurality of frequencies. An asymptotic high-frequency limit is determined and the electrical efficiency is estimated as a ratio of the high frequency resistivity limit to the low frequency resistivity. From the electrical efficiency, petrophysical parameters of a rock such as porosity and water saturation can be estimated.

Abstract: Resistivity measurements are made at a plurality of frequencies. An asymptotic high-frequency limit is determined and the electrical efficiency is estimated as a ratio of the high frequency resistivity limit to the low frequency resistivity. From the electrical efficiency, petrophysical parameters of a rock such as porosity and water saturation can be estimated. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A mineralogical record of whole core is produced by translating whole core relative to a X-ray diffraction source and detector and summing the resulting X-ray diffraction spectra from various surface portions of the core over an interval of the core.

Abstract: A method and apparatus for determining both the extent of setting of cement and strength of cement as it sets by utilizing a pulsed nuclear magnetic resonance spectrometer, to follow the cementation or hydration reaction of the cement. Cement samples can be agitated to simulate the transport and placing of a cement and/or exposed to temperatures and pressures similar to that of the environment wherein the cement will be placed and set.