基于钻井液侵入特征的阵列感应测井响应校正

受盐水钻井液侵入影响,储集层电测井响应会偏离地层真电阻率。为了准确实现对阵列感应电测井响应的侵入校正,基于油水两相渗流理论和岩电理论,按照孔渗比范围分类,应用数值模拟方法得到了不同地层物性条件下盐水钻井液侵入动态演化过程及其对阵列感应测井响应的影响关系。钻井液侵入模拟结果表明:在低孔渗地层中,储层物性和钻井液侵入时间是影响侵入剖面特征的主要因素,而钻井液侵入时间和侵入深度是阵列感应测井响应特征及其变化规律的主控因素。据钻井液动态侵入规律,考虑侵入压差、地层孔渗比、侵入时间等影响因素,建立了时间推移模拟电阻率校正法。实际井的阵列感应电测井校正结果表明,通过时间推移模拟法校正后的电阻率值计算出的含水饱和度与密闭取心井测量的含水饱和度吻合较好,验证了该校正方法的可行性和准确性。

CORRECTION OF THE ARRAY INDUCTION LOGGING RESPONSES BASED ON THE MUD INVASION CHARACTERISTICS

Influenced by the brine drilling liquid invasion,the electrical resistivity logging responses are prone to deviate from the true resistivities of the formations.In order to accurately realize the invasion correction of the responses of the array induction logging,based on the water-oil two-phase flowing theory and litho-electric theory,according to the classifications of the formation porosity-permeability ratio (~/K) scope,with the help of the numerical simulating method,the invasion dynamic evolution process of the brine drilling liquid and its effects on the array induction logging responses were acquired under the different physical properties.The invasion simulation results show that the invaded profile characteristics are mainly influenced by the reservoir property and the invasion time,simultaneously,the invasion time and invasion depth are the key controlling factors on the array induction logging responses.According to dynamic invasion rules and considering the pressure difference,~/K and invasion time and so forth,the correcting method of the time-lapse resistivity simulation was established.The actual corrected results of the array induction logging show that the calculated water saturation values by the resistivity from the correcting method are in consistent with those by the sealed coring well measurement values,so the feasibility and accuracy of this correcting method are verified.