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。
On the basis of the thin section observation, scanning electron microscopy analysis, and comprehensive analysis involving reservoir pressure coefficient, porosity type and size, throat features, and other characteristics of the data, it is found that the study area, Hutubihe Formation's lithologic reservoir is a Class I reservoir, and the reservoir possesses main characteristics, such as high porosity, high permeability, low displacement pressure, and a large throat. Compaction of the sandstone reservoir in the study area is from moderate-weak intensive. It is obtained from final study that although the content of the low degree maturity and the relatively poor ability plastic cuttings are higher, but the high-quality reservoirs are still able to form in the study area, the reason for that is mainly due to extensive development of high-energy micro-braided channel deposit, the mud content of high-energy micro-braided channel is lower, therefore the porosity and permeability is higher; the size of sand in the study area is mainly the lithic sandstone and fine particles, the larger particle size enhances the compressive strength of sandstone; the diagenesis is slow down because of the low geothermal gradient in the study area; the early hydrocarbon charging enhances the real capacity of the reservoir under the pressure, so that the original porosity can be preserved well; in the later stage, the structure in the study area is stable, big fault activities that do damage to oil and gas reservoir never happen, and the primary pores are not destroyed.