Method for identifying high-quality shale by using logging information

Abstract

The invention provides a method for identifying high-quality shale by using logging information, and belongs to the field of oil and gas exploitation and physical geography. The method comprises: firstly performing pre-processing on logging information, including performing environment correction, depth correction, and standardization; then performing the following steps: step 1, using a natural gamma-ray logging curve to distinguish a shale bed and a non-shale bed; step 2, using the ratio of a thorium curve and a potassium curve of natural gamma-ray spectrometry log and ratio of the thorium curve and the potassium curve to distinguish sedimentary environment of the shale bed; step 3, if the sedimentary environment distinguished in the step 2 is reduction and low-energy environment, calculating contents of organic matters and clay minerals in the shale bed; step 4, and on the basis of the step 3, identifying high-quality shale beds and non-high-quality shale beds.

Description

technical field [0001] The invention belongs to the fields of petroleum and natural gas exploration and development and geophysics, and in particular relates to a method for identifying high-quality mud shale by using logging data, and is especially suitable for unconventional oil and gas fields such as shale gas. Background technique [0002] Shale gas is an important part of unconventional oil and gas resources in the world. Shale gas resources are relatively abundant and the resource prospects are huge. North America is currently the only region in the world that has realized commercial exploitation of shale gas. The shortage of oil and gas resources has prompted China to accelerate the development of shale gas. At present, the exploration and development of shale gas has become a hot spot in domestic oil and gas exploration. Different from conventional gas, it is stored in mud shale. Therefore, the identification of high-quality mud shale formations has become a key facto...

AI Technical Summary

Problems solved by technology

However, this technology has the following problems: (1) It is impossible to identify the quality of the mud shale layer; (2) The information used is relatively single, and the identification results have certain limitations

This method has the following problems: (1) It does not make full use of natural gamma ray spectrum logging, which is rich in information and contains more geological significance; (2) It fails to form a systematic and comprehensive identification method

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