APPARATUS FOR MEASURING FILTRATION POTENTIAL AND DETERMINING UNDERGROUND FORMATION CHARACTERISTICS Russian patent published in 2012 - IPC G01V3/26 

FIELD: physics.

SUBSTANCE: invention relates to geophysics and can be used to determine in-place permeability at different depths. Characteristics of underground formations are determined using a group of electrodes to measure filtration potential in the formation and then interpreting data obtained using the electrodes. The electrodes are placed at fixed points opposite a finished well bore. The measured filtration potential values are generated by drilling with repression pressure, cutting the clay cake in the well bore, injecting acid or using any other method which causes fluid flow. The obtained data are interpreted to determine the location of cracks, determine in-place permeability, estimating formation pressure, controlling loss of flush fluid, detecting anomalous pressure etc. In particular, the transient process of changing stress corresponding to filtration potential, having a profile with a double peak, denotes presence of a crack in the formation.

EFFECT: high accuracy of determining formation characteristics.

22 cl, 33 dwg