Method for identifying lithology of three-dimensional volcanic rock

Abstract

The invention relates to a method for identifying the lithology of volcanic rock. The method comprises the following steps of: determining the types of rock needing lithological identification; calculating the content of each element in stratigraphic rock in percentage by weight by using the theory of oxygen closed mold on the basis of elemental capture spectroscopy logging information; classifying the lithology of volcanic rock by using a silicon-alkali classification method; extracting the rock structure information of different classes of lithology of volcanic rock on the basis of imaging logging information in combination with oilfield on-site coring analysis and geologic description; combining the rock components calculated according to elemental capture spectroscopy logging with therock structure information determined according to the imaging logging information together and converting a TAS two-dimensional plane into a three-dimensional plane by using the rock structure information as a third dimension scale; and realizing three-dimensional volcanic rock lithological identification by using an SVM (Support Vector Machine) method. By adopting the method, the coincidence rate of lithological identification can be improved to reach more than 90%, which is 10 times that of the traditional method.

Description

technical field [0001] The invention relates to a complex lithology reservoir such as volcanic rock and metamorphic rock, and a method for identifying volcanic rock lithology by using element capture energy spectrum logging data and imaging logging data. Background technique [0002] As a method of qualitative and quantitative evaluation of oil and gas reservoirs, well logging technology has played an important role in the evaluation of sandy mudstone and clastic rock oil and gas reservoirs, and has been paid more and more attention. However, logging technology has encountered new challenges in the interpretation and evaluation of volcanic reservoirs. The evaluation of volcanic rock reservoirs is the focus of the description of volcanic rock reservoirs, and the identification of volcanic rock lithology is the basis of volcanic rock reservoir evaluation. If the lithology cannot be accurately identified, it will directly lead to the omission of gas layers in the interpretatio...

AI Technical Summary

Problems solved by technology

However, at present, there are few core analysis data and a lack of standard basis for lithology refinement, which affects the improvement and development of lithology identification standards based on well logging data, especially the identification of excessive lithology such as dacite.

Elemental Capture Spectroscopy (ECS logging for short) can accurately measure the information of various elements that make up formation rocks, and provides a possibility to classify volcanic rock lithology from rock components; imaging logging (FMI , EMI logging, etc.) can reflect the structural information of formation rocks, and then use the differences in rock structures to divide lithology categories, but unfortunately, in previous studies, the two have not been well combined , failed to form an effective volcanic rock lithology identification technology

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