关键词: 岩石物理相, 储层参数, 解释模型, 惠州凹陷, 珠江组, 珠海组

Abstract: During the deposition period of Zhujiang and Zhuhai Formations in Huizhou Sag of the Pearl River Mouth Basin, several types of low-medium permeability sandstone reservoirs were developed in the target layer influenced by mother rock types and sedimentary environment. The pore structure, flow capacity and rock-electric properties are significantly different for different
types of reservoir. The traditional zoning and layered modeling methods have problems in application such as poor pertinence
of selected models and low interpretation accuracy. In order to improve the interpretation accuracy of reservoir parameters, this
paper starts with the reservoir classification by petrophysical facies. Based on core analysis data, parameters such as the average
grain size, mineral content, porosity, permeability and pore structure are optimally selected to characterize reservoir petrophysical
properties. The reservoir is accordingly classified into four petrophysical facies: feldspar quartz medium-fine sandstone facies,
clayey feldspar quartz fine sandstone facies, clayey feldspar quartz siltstone facies and calcareous quartz medium-fine sandstone
facies. Furthermore, sensitive log curves are extracted according to logging response characteristics of different petrophysical facies,and logging identification criteria for different types of petrophysical facies are established using the discriminant analysis
method. On this basis, fine interpretation model of reservoir parameters for each type of petrophysical facies is established and
calibrated by experimental data. The practical application results show that the accuracy of calculated porosity, permeability and
water saturation using petrophysical facies classification is significantly improved compared with the traditional method, which
meets the requirements of reserves calculation, and the logging interpretation conclusion is in good agreement with DST test result for new wells.