Shale gas-bearing evaluation method and device

Abstract

The invention provides a shale gas-bearing evaluation method and device, and relates to the field of shale gas development geology. The method includes the steps that firstly, a plurality of evaluation parameters of a horizontal well are obtained, the multiple evaluation parameters comprise the well logging interpretation porosity, the well logging interpretation total gas content, the whole hydrocarbon * mud density / drilling time and the pore pressure coefficient, then the multiple evaluation parameters are subjected to dimensionless processing to obtain a plurality of dimensionless evaluation parameters, and finally, the gas-bearing index value of the horizontal well is calculated based on the multiple dimensionless evaluation parameters and preset weight coefficients corresponding to each dimensionless evaluation parameter in the multiple dimensionless evaluation parameters. The provided shale gas-bearing evaluation method and device can reflects the gas-bearing property of the shale gas horizontal well more really and more effectively.

Description

technical field [0001] The invention relates to the geological field of shale gas development, in particular to a shale gas-bearing evaluation method and device. Background technique [0002] Gas-bearing property is an important indicator of shale gas geological evaluation, which directly affects the evaluation of whether shale gas blocks have industrial exploitation value. However, the occurrence state of shale gas includes three parts: free, adsorbed, and dissolved. There are many factors affecting the gas-bearing property, including shale's own factors (such as shale organic matter type, TOC, thermal evolution degree, fracture, porosity, mineral composition, etc.) , thickness, etc.) and external factors (such as shale burial depth, temperature and pressure, humidity, etc.), currently at home and abroad, the method of experimentally measuring adsorbed gas and (or) total gas content is usually used to evaluate the gas content of shale , but the use of experimental methods ...

AI Technical Summary

Problems solved by technology

However, the occurrence state of shale gas includes three parts: free, adsorbed, and dissolved. There are many factors affecting the gas-bearing property, including shale's own factors (such as shale organic matter type, TOC, thermal evolution degree, fracture, porosity, mineral composition, etc.) , thickness, etc.) and external factors (such as shale burial depth, temperature and pressure, humidity, etc.), currently at home and abroad, the method of experimentally measuring adsorbed gas and (or) total gas content is usually used to evaluate the gas content of shale , but the use of experimental methods to determine the gas-bearing properties of shale has the following problems: ① Adsorbed gas is an important component in shale, but it cannot fully represent the quality of shale gas-bearing properties; ② The cost of experimental research is high and the cycle is long; ③ To carry out basin-wide evaluation, a certain number of experimental samples that are evenly distributed in a large area are required, which is limited in many aspects and is not conducive to the evaluation of shale gas-bearing properties

[0003] According to the three-year development practice of the Wufeng-Longmaxi Formation shale gas reservoir in the Jiaoshiba Block Phase I production and construction area of ​​the Fuling shale gas field, it is found out that the measured gas content, gas measurement display, gas saturation, porosity, electrical resistance However, according to the actual application situation, there are still many problems: the measured gas content value in the field, under the same test method, with the Depending on the time of the test year, the gas content measured on site shows a trend of increasing year by year. At the same time, the measured gas content does not match the productivity of a single well. There is also a big contradiction in the field measurement of gas content in Fuling area

According to the actual situation, the gas content measured on site is affected by many factors. It is difficult to accurately characterize the real gas content of shale with current technology.

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