压实作用作为影响储层质量演化及预测的重要因素,常被理解为中浅层砂岩所经历的成岩作用,深层的压实作用长期被忽视,然而,库车前陆冲断带白垩系深层砂岩储层存在显著的压实分异现象.利用薄片、阴极发光和粒度分析对白垩系砂岩压实作用进行了深入研究.深层砂岩压实分异受构造挤压作用、胶结作用和砂岩粒径控制.压实作用在不同构造出现规律性的变化以及在纵向上呈现反深度的变化,而且随胶结程度降低,不同构造砂岩压实分异的幅度增大;中砂岩与细砂岩随压实程度增高,压实作用分异减小.深层储层仍存在较强的压实分异意味着在进行深层砂岩储层预测时,应该重视压实作用对深层储层质量差异的影响.%Compaction,a key factor for reservoir quality evolution and prediction,is generally considered as one of the ma-jor diagenesis of sandstones during shallow and intermediate burial instead of deep burial.However,prominent differential compaction is observed in the deep Cretaceous sandstone reservoirs of Kuqa foreland thrust belt and studied in-detail through thin section observation, CL and grain size analysis.Differential compaction of deep sandstone is mainly con-trolled by grain diameter,cementation and tectonic compression.The compaction degree of the deep sandstone reservoirs shows certain regularities from north to south on different tectonic positions and appears to change inversely with burial depth.Moreover,differentiation of compaction enhances with decreasing cementation.For medium-grained sandstone and fine sandstone,differentiation of compaction lowers along with their compaction degree.The existence of significant diffe-rential compaction in the deep-buried sandstone reservoir implies that much attention should be paiyed to the influence of compaction to reservoir quality differentiation when predicting deep-buried sandstone reservoirs.
展开▼
