在对四川盆地东北部宣汉县渡口镇羊鼓洞二叠系剖面详细研究的基础上,结合测井、地震等资料,对四川盆地东北部二叠系沉积相进行了分析,识别出了滨岸沼泽相、台地蒸发岩相、局限台地相、开阔台地相、台地边缘生物礁滩相、碳酸盐岩缓坡相和台盆相等7种沉积相带。指出二叠纪研究区发育下二叠统梁山组沉积期、栖霞组—茅口组沉积期和上二叠统吴家坪组—长兴组沉积期3次大的海侵—海退沉积旋回。在沉积演化和古地理分布研究的基础上,建立了研究区碳酸盐岩的沉积演化模式。

Oolitic dolostone is a vital type of carbonate reservoirs. The quantitative calculation and prediction of the reservoir permeability and gas saturation provide an important foundation for the further development of the reservoir, which could determine productivity and select the optimum exploitation layers in the dolostone. The general permeability model links geology and reservoir properties via rock number λ, which varies regularly within a depositional cycle. By using λ, the permeabilities and their changing trend can be indicated within a high resolution depositional framework. The cementation index m, an important parameter in calculating gas saturation by Archie formula, varies with the pore type in the dolostone. The permeability profile resulted from the permeability model by using the primary water saturation, porosity from thin sections, cores, debris, and well logging data; and the gas\|saturation profile from the Archie formula combining with the values of m and formation\|water resistivities in the oolitic reservoir, both of them act as the basis for optimizing development program of the gas reservoir in the dolostone after it was discovered.