低阻油层的电测井资料反演与动态侵入模拟

THE INVERSION OF ELECTRO LOG DATA AND SIMULATION OF DYNAMIC MUD-FILTRATE INVASION FOR LOW RESISTIVITY RESERVOIRS

高矿化度钻井液侵入是造成油层低电阻的重要因素之一,泥浆滤液侵入越深,对测井结果影响越大,甚至造成解释错误或油层漏失。采用非线性最小二乘原理进行电测井反演预处理,并将其同以多相流渗流、对流扩散理论为基础的电测井动态模拟相结合,能更加真实地反映动态侵入特点,获取原状地层真电阻率和流体饱和度,从而有效地改善低电阻率油气层电测井资料的有效性,为低电阻率油层的识别和评价提供可靠的依据。

The invasion of high-salinity mud is one of the most important factors to the formation with a low resistivity. The longer the time when the reservoir soaks in the mud, the greater the logging data were influenced, even resulting in interpreting mistake or oil layer loss. The electro logs were preprocessed on the basic of minimum mean square inversion principle. Also the dynamic electro logs were numerically simulated on the basis of multi-phase seepage flow theory and convection-diffusion theory. The characteristics of dynamic invasion could be more accurate provided by the combination of the two,and then true formation resistivity and fluid saturation were acquired. Therefore, the effectiveness of logging data were improved and more reliable in identifying or evaluating the low resistivity reservoir.