Quantitative Evaluation and Reservoir Division of Tight Sandstone with High Water Content in He 8 and Shan1 Formation in Maogeitu Area, Ordos Basin

In this paper, through the analysis of well log oil test data, observation of thin formation of rock, and high pressure mercury injection test, the quantitative evaluation and reservoir division of high water cut tight sandstone in He 8 and Shan1 Formation in Maogei area of Ordos Basin were studied. The results show that:1. It is suitable to use acoustic curve to establish a single pore model to calculate the porosity in the study area.2. There is a good correlation between the semi-logarithm of porosity and permeability. Based on this, the cubic polynomial relationship between them is established through mathematical regression, which can be used as the permeability model of He 8 and Shan 1 reservoirs in the study area.3.The Archie formula was applied to calculate the reservoir water saturation in the study area, wherein He 8: a = 1.0, b = 0.97, m = 1.86, n = 1.95, Rw = 0.06 Ω*m; Shan 1: a = 1.0, b = 0.91, m = 1.84, n = 1.89, Rw = 0.06 Ω*m;4.The reservoir is divided from six aspects: porosity, permeability, rock structure, sedimentary microfacies, diagenetic reservoir facies and mercury injection curve form. The reservoir in this area is divided into four types by taking this as the main parameter, and the classification evaluation standard of reservoir is established. The research results play a certain role in promoting the quantitative evaluation of high water cut tight sandstone reservoir parameters and reservoir division in the western Sulige area, and provide technical support for the gas field's sustained and stable production, and have a reference significance for the development of similar gas reservoirs.