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根据地震剖面解释和平衡剖面分析,库车前陆盆地秋里塔格构造带东段盐下地层的构造变形强度大于西段,东段的构造变形缩短率为13%~25%,形成了断层相关褶皱、叠瓦构造、双重逆冲构造等构造样式;西段的构造变形缩短率小于10%,形成了背冲构造、台阶状构造等断块构造。利用回剥原理,采用盆地模拟技术分析表明,东段的沉降速率大于西段。构造变形和沉降速率的差异性对储层成岩作用和物性产生了重要影响。东段的构造变形强,沉降速率大,储层的深埋时间长,导致储层的成岩作用强,处于中成岩A2—B期,储层的视压实率为37%~64%,储层物性较差;但强烈的构造作用造成裂缝发育,裂缝的存在提高了低渗透储层的渗透性能。西段的构造变形相对较弱,沉降速率较小,储层的浅埋时间较长,造成储层的成岩压实作用较弱,处于中成岩A1—A2期,储层的视压实率为24%~55%,储层物性相对较好。构造—成岩作用是影响库车前陆盆地秋里塔格构造带低渗透储层物性差异的关键地质因素。
According to the interpretation of seismic sections and the analysis of balance sections, the tectonic deformation intensity of the salt sub-stratum in the eastern section of the Qiulitag structural belt in the Kuqa foreland basin is greater than that in the western part. The shortening rate of structural deformation in the eastern segment ranges from 13% to 25% Fold structure, double thrust structure and other tectonic styles. The shortening rate of structural deformation in the western segment is less than 10%, forming a faulted block structure such as back-strike structure and step-shaped structure. Using the back-stripping principle, the analysis of basin simulation shows that the sedimentation rate of the eastern segment is greater than that of the western segment. The difference of tectonic deformation and sedimentation rate has an important influence on diagenesis and physical property of reservoir. The tectonic deformation in the eastern segment is strong and the sedimentation rate is large. The deep buried time of reservoirs results in strong diagenesis of reservoirs, which is in the A2-B diagenetic stage. The apparent compaction rate of reservoirs is 37% -64% However, the strong tectonism leads to the development of fractures. The existence of fractures improves the permeability of low-permeability reservoirs. The tectonic deformation of the western segment is relatively weak, the sedimentation rate is relatively small, and the shallow buried time of reservoirs results in a weak diagenetic compaction of the reservoirs. During the stages A1-A2 of the diagenetic rocks, the apparent compaction rate of the reservoir is 24% ~ 55%, reservoir properties are relatively good. The tectono-diagenesis is a key geological factor that affects the physical properties of low-permeability reservoirs in the Qilitage structural belt of the Kuqa foreland basin.