测井地震联合建模方法在地质导向前导模型中的应用

The Method of Log and Seismic Combined Modeling Used in the Geosteering Pre-Modeling

杨少虎 朱卫星 杨玉卿 赵永生

YANG Shaohu ZHU Weixing YANG Yuqing ZHAO Yongsheng

中海油田服务股份有限公司, 河北燕郊 065201; 中国石油(中国)有限公司天津分公司, 天津塘沽 300452

China Oilfield Services Limited, Yanjiao Hebei 065201, China; CNOOC Ltd. Tianjin Branch, Tanggu Tianjin 300452, China

在地质导向钻前建模过程时,通常利用水平井附近的多口邻井确定钻遇地层的深度及方位,该层的井间横向构造起伏可以利用解释层位来控制趋势;当井眼处测井解释的深度与解释的地震层位深度有差异时,建立的前导模型将有很大的误差。此文采用测井地震联合建模的方法来控制误差范围。该方法首先利用测井解释结果对大套的地震解释层位进行校正,根据每口井解释的小层厚度,利用滑动平均算法构造小层等厚体数据,然后利用校正后的地震解释层位横向约束控制地层起伏,建立每一地质小层的构造图,以此提高地质导向水平井着陆精度。实际资料验证,该方法会大大减小误差,能把模型误差控制在2 m的范围内。

In the process of pre-drilling geo-steering modeling, the wells near the horizontal well are used to determine the depth and azimuth of layers to be penetrated. The horizontal structural relief among wells is controlled by the seismic interpretation layer. If there are difference between the depth of seismic interpretation layer and the depth of log interpretation in the well location, predrilling geo-steering model will has great inaccuracy. In order to control the error range, the log and seismic combined ways were used in this paper. Firstly, calibrate the seismic interpretation horizons with log interpretation results. Then according to the subzone depth interpretated in the well, calculate the isopachous body data of subzone using moving average algorithm. Finally, control the horizontal structural relief with the calibrated seismic horizons, and compile the structural map for every geologic subzone to guide the work of geo-steering and improve the accuracy of the horizontal well. This method can control the inaccuracy rang within 2 m by verification with actual data.

https://doi.org/10.3969/j.issn.1008-2336.2012.02.082