四川盆地磨溪地区灯四段前积体产状定量解释及其应用

德阳-安岳裂陷槽东侧台缘发育大型丘滩带，为有利储层发育区，在研究区三维地震资料中发现大量台内前积反射结构，前积方向大致沿台缘带展布方向，与常规的碳酸盐岩台地前积方向存在差异，鲜见前人的研究文献。为此，利用磨溪地区三维地震资料，结合钻井资料标定，对比、追踪三维区内的多期前积地震反射结构，通过定量分析建立灯四段沉积期充填序列，分析该期德阳-安岳裂陷槽活动对沉积的控制作用。获得以下认识：①灯四段内部发育多期前积体，主要受高位期相对海平面缓慢下降控制，以横向前积为主，沿台缘坡折不断迁移。②前积坡折及其向陆一侧发育藻凝块石白云岩及藻砂屑白云岩有利储集岩相，为形成优质储层提供了物质基础。③利用台内区地震反射结构识别了各期前积坡折，可寻找储集岩发育相带，叠合岩溶古地貌，有望发现新的天然气富集区。上述基于地震反射结构的储层预测方法对于中国其他深层碳酸盐岩盆地勘探具有借鉴意义。

Quantitative interpretation and application of progradational reflection in the fourth member of Dengying Formation in the Moxi area,Sichuan Basin

A large mound shoal zone is developed on the east platform margin of the Deyang-Anyue rift trough, which is a favorable area for reservoir development. Plenty of intra-platform progradational reflection structures are found in the three-dimensional (3D) seismic data of the study area. The progradation is roughly distributed along the platform margin, which is different from the conventional progradation direction of carbonate platforms. These progradational reflection structures are less reported previously. Therefore, this study uses the 3D seismic data of the Moxi area and the calibration of drilling data to compare and trace the multi-stage progradational seismic reflection structures in the 3D area. Quantitative analysis helps to establish the filling sequence of the fourth member of the Dengying Formation in the deposition period, and the controlling effect of the Deyang-Anyue rift trough activity on deposition in this period is analyzed. The following conclusions are drawn:① The multi-stage progradation, mainly transverse progradation, occurs in the fourth member of the Dengying Formation, which is mainly controlled by the slow decline of the relative sea level in the highstand stage and continuously migrates along the platform-margin slope break. ② The progradational slope break and the development of algal-bound thrombolitic dolomite and algal-bound arenaceous dolomite on the continental side are favorable reservoir facies, which provide the material basis for high-quality reservoirs. ③ On the basis of intra-platform seismic reflection structures, the progradational slope break of each stage is identified, and the facies zones of reservoir rock development can be found. The superposition of the karst paleogeomorphology with these zones has the potential to reveal new gas enrichment areas. The proposed reservoir prediction method based on seismic reflection structures is of great reference significance for the exploration of other deep carbonate basins in China.