摘要
利用视电阻率求取含油气饱和度误差大。解决视电阻率与真实电阻率差异问题,一般通过校正图版和电阻率反演这2种方案。校正图版均为理想模型所建立,最大问题是单因素叠加校正,造成误差很大,反演算法综合考虑了井眼、地层侵入带、围岩等因素,比图版法更合理。但目前基于阵列侧向测井资料所用的三参数或五参数反演,构建的正演侵入地层模型为井眼、侵入带、原状地层,电阻率变化为台阶状变化,这与实际地层侵入特征不符。提出基于改进的三参数Logistic函数的电阻率渐变侵入地层建模方法,采用并行差分进化算法实现了沿地层径向的电阻率连续反演。利用三层正演模型对算法进行了验证,无论是高侵模型还是低侵模型,反演电阻率接近真实值,误差在1%以内。
Due to factors such as wellbore,drilling mud intrusion and surrounding rock,the resistivity(apparent resistivity)from electrical logging data is very different from true formation resistivity,so that a large error occurs to the oil saturation calculated using apparent resistivity.Generally correction charts and resistivity inversion models are used to eliminate the difference.A correction chart is established by an ideal model.The biggest problem is single factor superposition,so it may cause a large error.An inversion model takes such factors into account as wellbore,intruded zone and surrounding rock,so it is more reasonable than a correction chart.The forward intrusion model based on three-parameter or five-parameter inversion using array lateral logging data considers wellbore,intruded zone and undisturbed formation,so that the resistivity changes as steps,and is inconsistent with actual intrusion characteristics.A resistivity gradient intrusion formation model is proposed based on improved Logistic function.It realizes continuous inversion of resistivity along radial formation direction using parallel differential evolution algorithm.The algorithm was verified by a three-layer forward model.Whether it is a high-invasion model or a low-invasion model,the resistivity inverted is close to true formation resistivity-the error is less than 1%.
作者
姜黎明
贺飞
卢春利
曹景致
郭英才
张培军
JIANG Liming;HE Fei;LU Chunli;CAO Jingzhi;GUO Yingcai;ZHANG Peijun(Technology Center,CNPC Logging CO.LTD.,Xi’an,Shaanxi 710077,China;Well Logging Key Laboratory,CNPC Logging CO.LTD.,Xi’an,Shaanxi 710077,China)
出处
《测井技术》
CAS
2019年第3期247-251,共5页
Well Logging Technology
基金
“十三五”国家科技重大专项多维高精度成像测井系列(2017ZX05019-001)
中国石油集团公司重大科技专项(2017B-3705)
