关键词: 致密砂岩气, 岩石类型, 测井响应特征, 三步剥离法, 连续自动判别

Abstract: Carboniferous and Permian tight sandstone gas reservoirs are developed in Daning area of Ordos Basin, with the characteristics of wide horizontal distribution and stable vertical distribution. According to core, well test and other data, the tight sandstone gas reservoirs in Daning area have various rock types and different rock types, and there are obvious differences in reservoir physical properties and gas bearing properties. It is difficult to evaluate the tight sandstone gas reservoir rock types by conventional logging methods. Through integrated analysis of geologic and core data, four main rock types of tight sandstone gas reservoirs in the target block are determined, namely quartzose sandstone, lithic quartzose sandstone, feldspar lithic sandstone and lithic sandstone. On the basis of clarifying the response characteristics of the logging data of the four main rock types, the compensated density, compensated acoustic wave, compensated neutron and gamma ray logs are optimized, and the "three-step stripping method" is used to carry out the fine evaluation of rock types, which effectively improves the lithology identification accuracy of tight sandstone gas reservoirs and realizes the continuous and automatic discrimination of rock type classification.This method effectively solves the problem of rock type logging evaluation of tight sandstone gas reservoirs and improves the precision of lithology evaluation using conventional logging data.

Key words: tight sandstone gas, rock type, logging response characteristic, three-step stripping method, continuous and automatic discrimination