A Measuring Method of Clay Content in Complicated Formation Based on Electrical Imaging Logging Data

Abstract

The invention provides a method for measuring clay content in complex formations based on electrical imaging logging data, including: logging of key well data in the block, and core data collection; performing ground gamma measurement and X-ray diffraction analysis on the core respectively to determine the core content Gamma value and clay content; use the comparison of surface gamma value and logging gamma value to realize the depth homing of core; read the electrical imaging logging data corresponding to the actual depth of core and perform image preprocessing; Conduct histogram statistics on the electrical imaging logging data to obtain the resistivity distribution; apply the conjugate gradient optimization technology to obtain the limit of the resistivity distribution range of the mudstone, and then count the clay volume content; combined with the clay content obtained from the experiment, the volume content is corrected into mass Score, get a reliable clay content. This method can effectively meet the clay content measurement of complex formations (complex lithology, thin interbeds and their development), and is of great significance for the study of oil and gas reservoir saturation models and additional conductivity.

Description

technical field [0001] The invention belongs to the fields of geophysical well logging or petroleum geology, and in particular relates to a method for accurately measuring the clay content of complex formations by using electrical imaging logging data and core analysis data. Background technique [0002] Clay is very common in the formation and is an important factor affecting the electrical properties, seepage performance and storage space effectiveness of the reservoir. In complex formations, rock skeleton minerals and their content vary greatly, and sand-shale interbeds are generally developed, making it difficult for conventional logging information such as natural gamma ray, resistivity, sound wave, density, neutron and spontaneous potential to reflect sand-shale information. This makes the measurement of clay content difficult. [0003] At present, the commonly used method for clay content modeling is still based on conventional well logging, which has poor measuremen...

AI Technical Summary

Problems solved by technology

In complex formations, rock skeleton minerals and their content vary greatly, and thin interbeds of sand and mudstone are generally developed, making it difficult for conventional logging information such as natural gamma ray, resistivity, sound wave, density, neutron and spontaneous potential to reflect sand and mudstone information. This makes it difficult to measure the clay content

[0003] At present, the commonly used method for clay content modeling is still based on conventional well logging, which is less effective in formations with thin interbeds and frequent changes in framework minerals

Although some special logging techniques such as electrical imaging logging, array acoustic logging and nuclear magnetic resonance logging can compensate for the low resolution of conventional logging data, domestic and foreign scholars have not deeply analyzed their relationship with clay development. There is also a lack of methods for applying these data to calculate clay content

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