Gas Content Measurement Method Of Low Resistivity Shale Reservoir In South Sichuan

With more and more attention paid to shale gas,the development of shale gas in China has also increased.Shale reservoirs with certain reserves have been found in Sichuan and Yunnan.The time of shale gas development in China is not as long as that in North America,so the successful experience of North America has been used for reference in many aspects.In addition,due to the complexity and difference of geological conditions in China,there are some difficulties in the development process.The shale reservoirs in Sichuan Basin often have low resistance,which is different from the high resistance characteristics of conventional shale reservoirs,so it is difficult to interpret and evaluate the logging data.There are many reasons for low resistivity of shale reservoir,such as the content of formation water,mineral content and the characteristics of organic matter.Resistivity is also an important information for the calculation of water saturation in the study area.Using resistivity curve reconstruction and dual water model considering the parameters of clay ion exchange capacity,and combine the experimental data to carry out the calculation method of low resistivity saturation.In the reconstruction of resistivity,several petrophysical models are selected for comparison,and the differences between different models are compared to find out the most suitable model for the study of strata.In the calculation of water saturation,the phenomenon of low resistance is also fully considered,so the clay mineral part that causes low resistance is added in the calculation of water saturation,so the final result is more accurate.Finally,according to the logging curve information and the established petrophysical model,the reservoir is evaluated by logging,and the calculated parameters are used to evaluate the gas bearing property of the formation.