川西深层碳酸盐岩岩溶储层预测

川西北部九龙山地区深层茅口组碳酸盐岩沉积后遭受剥蚀和淋滤溶蚀作用,岩溶体储层较发育.茅口组作为下二叠统重要产气层系,具有巨大的天然气勘探潜力.为了进一步提高岩溶体储层的预测精度,通过开展岩溶体上覆地层反射结构分析,茅二段岩溶体地震相研究,茅口组剥蚀后的微古地貌恢复,岩溶体地震属性特征分析等研究工作,对茅二段岩溶体分布情况进行了定性综合预测.利用伽马反演方法预测茅二段生屑灰岩,并在此基础上通过研究采用多属性储层孔隙度反演预测方法进行茅二段岩溶体储层的定量预测.结果表明:定性-定量预测相结合的储层预测方法,对茅二段岩溶体储层的刻画更为有效、可靠,从而为川西北九龙山地区茅口组的开发规划和选区提供重要依据.

Karst Reservoir Prediction In the Deep of Western Sichuan Basin

Carbonates of Maokou formation in the Jiulongshan area, western Sichuan basin, were subject to long-term weathering, denudation and dissolution, leading to karst developed. As an important lower Permian gas producer, Maokou formation has great potential for natural gas exploration. In order to improve the the prediction accuracy of karst reservoir, the distribution of karst body is predicted qualitatively by analyzing the seismic reflection structure of the overlying strata of karst body, studying the seismic facies of the 2nd Maokou member(P1m²), rebuilding the paleogeomorphology, analyzing the characteristics of the seismic attributes of karst body and so on. Gamma inversion was used to predict the biological beach thickness distribution of P1m² member, and on this basis, multi-attributes inversion was used to quantitatively predict the karst reservoir. The result shows that the prediction method combined with qualitative and quantitative prediction is more effective and reliable for the characterization of karst reservoir, thus providing an important basis for the development of Maokou formation in Jiulongshan area.