电化学测井理论研究及其应用的新进展(上)

我国陆相沉积的油气田储层粘土含量较重，其阳离子交换量Ｑｖ对测井响应，尤其是对电化学测井响应及其解释影响较大。油田注水开发油层水淹后，地慨水电阻率Ｒｗ变化不定，成为水淹层评价中的难题。Ｑｖ和Ｒｗ均为地层电化学参数，最好的办法是用电化学测井方法求解它们。文中论述了粘土对电化学测井响应影响的机理，在此基础上推导了自然电位和激发极化电位测井响应方程，给出了进行地层阳离子量校正的自然电位的激发极化电位理论模

New Advances in Theoretical Study and Practical Application of Electrochemical Logging

Clay content of continental sedimentary reservoir in China is rather high. And cation exchange capacity (QV) in clay has strong effect on well logging response, especially on the response and interpretation of electrochemical log. When the oil bearing zones are waterflooded, the difficulty in evaluating waterflooded layers results from the variation of formation water resistivity (Rw). Both QV and Rw are electrochemical parameters. The best way to derive them is electrochemical method. The mechanism related to the effect of clay on electrochemical log response is stated in this paper. The log response equations are inferred for spontaneous potential and induced polarization potential and their theoretical models are given for the correction of QV. The models and interpretation methods to derive salinity of formation water (formation water resistivity), QV and oil saturation quantitatively are also given. All this will improve the precision of log interpretation and provide accurate geological data for the evaluation of waterflooded zones and the determination of remaining oil saturation in oilfield exploration and development.