Logging division method and system of shale isochronous stratigraphy based on the characteristics of graptolite zone

Abstract

Disclosed are a method and system for shale isochronous formation logging division based on graptolite zone characteristics. The method includes: determining the type of graptolite zone in the area where the standard well is located by identifying standard wells; for new wells in the area, preliminarily determining the graptolite zone of each graptolite zone according to each local peak of the logging gamma curve. position; determine the half-amplitude corresponding to each local peak in the upward direction when it falls to the local minimum or increases to the local maximum as the upper boundary of the graptolitic zone corresponding to the local peak, and the above The lower boundary of the graptolite zone. The invention can provide a fine and accurate division scheme for the vertical and plane distribution of shale gas enrichment and high-yield sections in different regions, and effectively improve the fineness and accuracy of shale gas enrichment and high-yield sections under the framework of isochronous stratigraphic comparison. It improves the prediction accuracy of the shale gas horizontal well target area, and provides a reliable technical means for the prediction and evaluation of the enriched and high-yield intervals in shale gas exploration and development.

Description

technical field [0001] The invention relates to the technical field of shale gas exploration and development, and more particularly, to a method and system for logging and dividing shale isochronous formations based on the characteristics of graptolite zones. Background technique [0002] The Wufeng Formation-Longmaxi Formation shale gas reservoirs in the Sichuan Basin and its surrounding areas are currently the key areas for exploration and major production areas. Two national-level shale gas demonstration areas, Jiaoshiba and Weiyuan-Changning, have been built. good shale gas exploration potential in this area. At present, the exploration of shale gas is mainly divided by lithology and logging curve. Due to the small difference of shale depositional environment, the shale geochemical characteristics, mineral characteristics and physical characteristics are less different in section and plane, and the It is difficult to distinguish the hydrocarbon generation capacity, rese...

AI Technical Summary

Problems solved by technology

The small number of coring wells limits the large-scale application of this technology, and the cost of coring is too high. The number of coring wells in development wells in shale gas development zones is small, but each well has a well logging curve, so It is necessary to establish methods and techniques to divide shale gas-enriched and high-yield intervals between graptolite belt characteristics and log curves, so as to improve the economy and effectiveness of shale gas-enriched and high-yield intervals

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