基于主控因素的煤层气富集区地震预测技术应用研究

Application of coalbed methane accumulation zone seismic prediction technology based on main geological controlling factors

针对煤层气的特殊性及其地震预测的难点,研究并提出了基于影响煤层气富集的主控因素开展煤层气富集区地震多参数综合预测的思路与方法。选择SHS地区为试验靶区,通过地质分析总结出煤储层的构造形态、煤层厚度、盖层(顶板)岩性、沉积环境(煤质)、裂缝发育程度和煤储层物性(渗透性)等6项因素是控制本区煤层气富集的主要因素;针对不同的主控因素,选用地震构造解释、地震属性分析、地震波阻抗反演、地震相分析、ESP裂缝检测、地震弹性参数反演等技术分别进行预测分析;在相关性分析确定出各项地震技术预测成果权重系数的基础上,应用层次分析法(AHP)进行综合评价,实现了SHS地区煤层气富集区的综合预测。预测结果与煤层气钻井结果具有较好的一致性。

Aiming at the characteristics of coalbed methane and the difficulties for seismic prediction,we proposed an integrated seismic prediction method by using multi-parameters to identify coalbed methane enrichment zone based on main geological controlling factors.Taking SHS area as target,by geologic analysis,we concluded six main controlling factors for the accumulation of coalbed methane,including structure pattern,coalbed thickness,lithology of overlays,sedimentary environment(coal quality),fractures development and coalbed permeability.Then,seismic structure interpretation,seismic attributes analysis,seismic acoustic impedance inversion,seismic facies analysis,ESP fracture detection technique and seismic elastic parameters inversion is chosen to separately analyze the above controlling factors.After setting weight coefficients of prediction results of all the seismic techniques,AHP evaluation is conducted to realize the comprehensive prediction of coalbed methane enrichment zone of SHS region and the prediction result shows good consistency with well drilling data.