Mineral ingredient content and porosity calculating method for shale gas stratum

Abstract

The invention discloses a mineral ingredient content and porosity calculating method for a shale gas stratum. The method comprises the following steps that routine integrated logging data is used to calculate the total clay mineral content, calculate contents of three different types of clay materials by decomposition, calculate the content of organic matters, and calculate the content of pyrite; a logging value of a logging curve is corrected; if there is no element capture logging result, a regional relation is established according to the integrated logging data, and the content of a carbonatite mineral is calculated; if there is an element capture logging result, the carbonatite mineral content in the element capture logging accomplishment is used directly; quartz, feldspar, calcite and dolomite minerals and the porosity are optimized and constrained; and a calculation result is normalized. According to the invention, contents of different mineral ingredients of the shale gas stratum are calculated according to the logging data, the mineral ingredient content and porosity calculating precision of the shale gas stratum are improved, and basis is provided for accurate calculation of the brittleness index and gas content of the shale gas stratum.

Description

technical field [0001] The invention relates to a method for calculating the contents of up to nine kinds of minerals and the size of porosity in a shale gas formation by using logging data, and belongs to the field of logging data interpretation and evaluation in oil and gas exploration. Background technique [0002] Shale gas is an unconventional oil and gas reservoir. The shale gas formation is composed of lithological minerals and pores (fractures). The lithological particles are not only much finer than the conventional sandstone formation, but also the mineral diversity of the formation is complex. , except for a small amount of minerals with low content, it generally mainly includes clay (illite, chlorite, montmorillonite), quartz, feldspar, calcite, dolomite, organic matter (kerogen), pyrite, etc. The logging response characteristics of each mineral component vary greatly, and the content of each mineral component varies greatly in each shale gas development block. T...

AI Technical Summary

Problems solved by technology

[0005] 2. Domestic methods for calculating complex minerals using logging data for shale gas formations are immature. Quartz and feldspar are classified as siliceous minerals, calcite and dolomite are classified as carbonate minerals, and different types of clay minerals are classified as A clay mineral, although the calculation method is simplified, the result cannot correctly reflect the characteristics of the real mineral composition in shale gas formations

[0006] 3. Foreign logging companies represented by Schlumberger rely more on formation element capture logging data when calculating the complex mineral components of shale gas, and cannot calculate the corresponding complex mineral composition

[0007] 4. It is very difficult to accurately calculate the content and porosity of complex mineral components when there are only conventional comprehensive logging data