Method and device for analyzing brittle cover layer closeness of fault block entrapment

Abstract

The invention provides a method and device for analyzing the brittle cover layer closeness of a fault block entrapment, and the method comprises the steps: building a fault model of a target brittle cover layer section in a brittle cover layer section of a fault block entrapment of a sand-mudstone interbed stratum, and determining the lithological attributes of each layer section in the fault model; according to a preset sandstone filtering window size and the lithology attribute of each layer section, determining a calculation mode of a cover layer sealing factor of each layer section, and based on the calculation mode, calculating the cover layer sealing factor of each layer section; and according to the capping layer sealing factor of each layer section and the target brittle capping layer section sealing factor threshold value, achieving capping layer sealing performance analysis of the target brittle capping layer section on the section. The method and device can analyze the sealing performance of the brittle cover layer on the section, and are high in accuracy.

Description

technical field [0001] The invention relates to the field of seismic exploration, in particular to a method and device for analyzing the sealing performance of brittle cap rocks trapped by fault blocks. Background technique [0002] In the exploration of fault-block oil and gas reservoirs, it is one of the important elements to analyze the damage degree of faults to cap rocks. The failure mechanism of faults to cap rocks with different brittle toughness is quite different, resulting in different capabilities of vertical damage to cap rocks after combination of faults and cap rocks. , different evaluation methods should be adopted for different brittle and ductile caprocks. For the caprock in the ductile stage, it generally has the sealing ability on the fracture surface; for the caprock in the brittle-ductile transition stage, the mudstone smear factor is used to evaluate the extent of the argillaceous caprock being damaged by fracture; for the brittle stage For cap rocks,...

AI Technical Summary

Problems solved by technology

For the caprock in the ductile stage, it generally has the sealing ability on the fracture surface; for the caprock in the brittle-ductile transition stage, the mudstone smear factor is used to evaluate the extent of the argillaceous caprock being damaged by fracture; for the brittle stage For cap rocks, the disconnected thickness method is usually used, but the representation of this method is based on a large number of drilling statistics charts or the distribution on a certain stratigraphic plane, and does not realize the display of its distribution on the fault plane, especially It is impossible to show the change of sealing ability of caprock at different positions on the section, which makes the accuracy of sealing analysis low

Therefore, the above method cannot intuitively reflect the sealing difference of the brittle cap rock on the cross-section, and has limitations in application.

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