构造挤压对碎屑岩储层破坏程度的定量表征——以库车坳陷依奇克里克构造带侏罗系阿合组为例

库车坳陷依奇克里克构造带侏罗系阿合组沿东西方向埋深相差小于1 km,但储层物性、孔隙结构差异大。储层平均孔隙度相差3倍,渗透率至少相差一个数量级。自西向东,微孔隙有逐渐减少的趋势,粒间孔逐渐增加。研究区内构造应力对储层有重要的影响。通过自西向东选取迪北102井、依南5井、吐孜4井和吐东2井阿合组粗粒长石岩屑砂岩样品开展分析,探讨了一种既考虑岩石表观体积变化、又考虑杂基体积变化的模型来定量分析压实作用对储层的破坏程度。结合埋藏史分析和平衡剖面恢复,用深时指数和伸缩率参数开展回归分析,区分出横向挤压和垂向压实对储层的破坏程度,比较了构造挤压作用对储层孔隙空间的贡献率。研究结果表明：依奇克里克构造带自西向东阿合组储层的压实减孔率逐渐减小;构造挤压减孔在压实减孔中占比呈两侧高、中部低;构造裂缝对储层的改善程度远远小于构造挤压对储层的破坏程度。

Quantitative characterization on the clastic reservoir destruction by tectonic compression: a case study of the Jurassic Ahe Formation in Yiqikelike structural belt,Kuqa depression

The burial depth difference of the Jurassic Ahe Formation in the Yiqikelike structural belt of Kuqa depression is less than 1 km along the east-west direction, but the physical properties and pore structure of reservoir are quite different. The average porosity of reservoir shows a three-fold difference, and the permeability of reservoir differs by at least an order of magnitude. From west to east, the micropores gradually decrease, but the intergranular pores gradually increase. Tectonic stress has an important impact on reservoir in the study area. The paper analyzes the coarse feldspar lithic sandstone samples of Ahe Formation in the Well Dibei102, Well Yinan5, Well Tuzi4 and Well Tudong2 from west to east, and proposes a model considering the volume changes of both rocks and matrix to quantitatively analyze the reservoir destruction by compaction. In combination with burial history and balanced cross-section restoration, the regression analysis was carried out with depth-time index and contraction ratio, to distinguish the destruction effect of reservoir by lateral compression and vertical compaction, and to compare the contribution rate of tectonic compression to reservoir pore space. The results show that the porosity loss caused by the compaction of Ahe Formation gradually decreases from west to east in Yiqikelike structural belt. The porosity loss caused by tectonic compaction is characterized by high on both sides and low in the middle. The effect of structural fractures on reservoir improvement is far less than that of tectonic compression on reservoir destruction.