松辽盆地齐家古龙-三肇凹陷超压对成岩作用的影响

松辽盆地齐家古龙-三肇凹陷青山口组以上地层发育3套明显的压力体系，其中作为勘探重点的青山口组和嫩江组泥岩超压不仅控制烃类的生成，还对相邻储层具有深远影响.在前人研究基础上，应用热解分析、X射线衍射、镜下鉴定、扫描电镜、铸体薄片鉴定等资料，研究了超压对地质流体活动及成岩作用的影响.结果表明，超压不仅抑制了粘土矿物转化，还抑制了烃类结构的演化.另外，成岩作用中的压实作用、胶结作用对于超压的抑制有明显的响应.超压并不能直接影响溶解作用，而是通过地质流体间接对其产生影响，主要表现为由次生孔隙产生造成的孔隙度增加. 

Effecting of Overpressures on Diagensis in the Qijiagulong-Sanzhao Depression of Songliao Basin

There are 3 sets of obvious overpressure systems in the strata above the Qingshankou Formation in Qijiagulong-Sanzhao depression, Songliao basin. The overpressure in the Qingshankou (K₂qn) and Nenjiang (K₂n) Formation mud rock which is the key zone of exploration which not only controls the formation of hydrocarbon, but also impacts the adjacent reservoir property deeply. Based on the previous studies, this paper utilizes abundant materials, including thermal decomposition, X-ray diffraction, microscope analysis, SEM and blue epoxy resin-impregnated thin sections, to study the effect of overpressure on diagenesis. The results indicate: (1) the overpressure constrained the transformation of clay minerals, and also depressed the evolution of hydrocarbon structure. (2) The compaction and cementation during diagenesis responded apparently to the overpressure depression. The overpressure didn't affects dissolution directly, but via the geo-fluids indirectly, causing the increase of porosity by induced pore.