川中资阳地区茅口组岩溶储层识别模式及分布预测

Recognition mode and distribution prediction of Maokou Formation karst reservoir in Ziyang area, central Sichuan Basin

李素华

LI Suhua

中国石化西南油气分公司勘探开发研究院，四川 成都 610041

Exploration and Development Research Institute, Southwest Oil & Gas Company, SINOPEC, Chengdu 610041, China

近期，二叠系茅口组岩溶储层相继在川中和川南斜坡或向斜区取得油气突破。资阳地区紧邻威远和高石梯￣磨溪地区，具有相似的地质背景，预示着资阳地区茅口组具有良好的勘探潜力。为了明确资阳地区茅口组岩溶储层发育情况，文中利用高精度三维地震资料和典型钻井井震标定，结合正演模拟结果建立了顶部、层间和与断层相伴生的3类岩溶储层识别模式；利用古地貌、地震相、地震反演和断裂、裂缝预测等数据综合确定3类岩溶储层的分布，形成了一套低勘探区茅口组岩溶储层预测技术。其中，微古地貌高地是岩溶储层发育的有利地貌单元，有利沉积相带控制生屑滩发育的规模，断裂、裂缝进一步改善岩溶储层发育的程度，结合地震反演预测结果可定性、定量确定岩溶储层发育有利区。研究表明：研究区中南部发育生屑滩有利沉积相带，且位于岩溶残丘和岩溶坡地高部位，与2条NE向大断层共同控制3类岩溶储层和微裂缝的分布。该研究成果为资阳地区茅口组下一步勘探提供了重要技术支撑。

Recently, the Permian Maokou Formation has successively made oil and gas breakthroughs in the slope or syncline area of the central and southern Sichuan Basin. Ziyang area is close to Weiyuan and Gaoshiti-Moxi area, which has a similar geological background, indicating that the Maokou Formation in Ziyang area has good exploration potential. In order to clarify the development of karst reservoir of Maokou Formation in Ziyang area, by using high-precision 3D seismic data and typical well-seismic calibration, three types of karst reservoir identification models of top, interbed and fault concomitant were established combined with forward modeling results. The distribution of three types of karst reservoirs was determined comprehensively by using paleogeomorphology, seismic facies, seismic inversion and fault and fracture prediction. A set of karst reservoir prediction technology of Maokou Formation in low exploration area was formed. The micro-paleogeomorphic highland is the favorable geomorphic unit for the development of karst reservoir, the favorable sedimentary facies zone controls the scale of the development of bioclastic beach, and the fault and fracture further improve the development degree of karst reservoir. Combining with the seismic inversion prediction results, the favorable karst reservoir development area can be qualitatively and quantitatively determined. The research shows that favorable sedimentary facies belt of bioclastic beach is developed in the central and southern part of the study area, and it is located in the high parts of karst monadnock and karst slope and controls the distribution of three types of karst reservoirs and microfractures together with two NE trending big faults. The research results provide important support for the next exploration of Maokou Formation in Ziyang area.

10.6056/dkyqt202304017