Spectral Analysis Method for Calculating Mineral Content and Brittleness Index of Shale Reservoir by Imaging Logging

Abstract

The invention discloses a spectrum analysis method for calculating mineral content and brittleness index of shale reservoir in imaging logging. The method comprises the steps that 1) imaging logging data is preprocessed; 2) a histogram of preprocessed data of different electrodes of original imaging logging is analyzed; 3) the histogram of the data of the different electrodes of imaging logging isstandardized; 4) the standardized imaging data is enhanced; 5) static imaging data is described as an imaging mineral spectrum; 6) the standard histogram and imaging spectrum are used, rock core analysis data is used to describe logging, a spectrum of minerals is unfolded according to spectral distribution positions, and content of clay mineral, quartz and calcite mineral is obtained; and 7) theproportion of the quartz in the total mineral content is calculated to obtain the brittleness index in the shale gas. The method has a higher precision is practical calculation, micro change of the content of the stratum minerals can be reflected accurately, and the calculated brittleness index Brite can reflect the stratum brittleness change effectively.

Description

technical field [0001] This technology relates to the field of shale gas reservoir evaluation technology, and mainly involves the technical method of quantitatively calculating the mineral content and brittleness index of shale gas reservoirs by using imaging logging data. Background technique [0002] Breakthroughs have been made in the exploration and development of shale gas represented by the marine Longmaxi Formation shale gas in southern Sichuan, providing an important support for the stable growth of my country's oil and gas resources. Shale gas reservoirs are generally developed using horizontal wells + staged fracturing. Statistical experience at home and abroad shows that in shale gas horizontal wells, the contribution of each reservoir section to production capacity varies greatly. About 70% of shale gas production is mainly produced in 30% of shale gas reservoir sections, which determine the productivity contribution of each section. The main controlling factors...

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Problems solved by technology

These two methods have their own characteristics, but there are also certain limitations: (1) These two methods are based on conventional logging data, and their sampling accuracy is 0.1 m or 0.125 m, while the sampling accuracy of imaging logging data is 0.0025 m , the longitudinal resolution of imaging logging is more than 40 times higher than that of conventional logging

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