New understanding on negative anomaly of micro-electrode log curves in the low permeability reserves

Abnormal negative separations of micro - electrode log curves are very common in the low permeability reservoir. According to micro-electrode log principle, the negative separation of the micro - electrode curves is explained, from which it is concluded that the causes resulting in the separations are: poor reservoir permeability, weak mud invasion and no mudcake formation. In combination with oil testing data after fracturing, the separations are used in low permeability reservoir discrimination and it has achieved good effectiveness.