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通过岩石薄片观察、扫描电镜分析、油藏压力系数、孔隙类型及大小、喉道特征等综合分析知,研究区白垩系呼图壁河组岩性油气藏储集层属于I类储层,具有高孔隙度、中高渗透率、低排驱压力、大喉道为主、孔隙连通性较好的物性特征,为优质储层。并根据埋藏深度和颗粒接触类型对研究区压实作用进行定量分析,可知研究区为中弱压实强度。并最终研究得知,虽然研究区储层塑性岩屑含量较高,但仍为优质储层的主要原因是,研究区广泛发育辫状高能河道沉积微相,该沉积微相泥质含量比低能河道的低,故孔隙度和渗透率较高;研究区的岩屑砂岩粒径大小主要为中粒和细粒,较大的砂岩粒径值增强了砂岩的抗压性;中新生代以来,研究区地温梯度为0.02—0.022℃/m,低地温梯度减缓了成岩作用的进行;烃类的早期充注增强了储层抗压实能力,使原始粒间孔隙得以保存;后期该区构造稳定,未发生大的断裂活动破坏油气藏,使原生孔隙也没有遭到破坏。
According to the comprehensive analysis of rock slices, SEM, reservoir pressure coefficient, pore type and size and throat characteristics, the lithologic reservoirs of Hutubihe Formation in Cretaceous belong to class I reservoirs and have High porosity, high permeability, low discharge pressure, large throat-based, good connectivity of the pore physical properties, high-quality reservoir. According to the depth of burial and the type of particle contact, the compaction of the study area was quantitatively analyzed. It can be seen that the study area is of moderately weak compaction strength. And the final study shows that, although the plastic cuttings content in the study area is relatively high, the main reason for the still high quality reservoirs is the extensive development of braided high-energy channel sedimentary microfacies in the study area, Because of the low channel, the porosity and permeability are higher. The size of the lithic sandstone in the study area is mainly medium-grain and fine-grained, and the larger sandstone grain size enhances the compressive resistance of sandstone. Since the Meso-Cenozoic, The geothermal gradient in the study area is 0.02-0.022 ℃ / m, and the low geothermal gradient slows down the diagenesis. The early filling of hydrocarbons enhances the compressive strength of the reservoir, so that the original intergranular pores can be preserved and the structure is stable in the later period , No major fault activity ruptured the reservoirs, and the original pores were not damaged.