A karst breccia identification method

Abstract

The invention relates to a karst breccia identification method. The method comprises the following steps of S1, according to different geneses, dividing karst breccia into karst fracture breccia, karst collapse breccia and karst accumulation breccias; S2, according to identification characteristics, identifying the karst fracture breccia, the karst collapse breccia and the karst accumulation breccia from a rock core; S3, using the identified karst fracture breccia, the karst collapse breccia and the karst accumulation breccia to correspond to a conventional logging curve at the same position with the rock core, and summarizing the response characteristic of the conventional logging curve of a corresponding core section; and S4, according to the acquired three types of breccia response characteristics, establishing a karst breccia identification model, and according to the karst breccia identification model, finally realizing the breccia identification of the whole well section of a target layer. The technology provided in the invention can be well applied to a karst type reservoir. Under the condition of less well drilling cores, accumulated breccia can be rapidly identified, whichis good for searching a favorable reservoir development area.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration and development, in particular to a method for identifying karst breccia. Background technique [0002] Lithology identification is the basic work of reservoir evaluation. Lithology identification of the reservoir is currently carried out. Common logging identification methods include: crossplot method, and various mathematical discriminant analysis methods. [0003] The crossplot method is most widely used to identify formation lithology using conventional logging data. The intersection graph method selects two physical quantities that are sensitive to lithological responses to intersect to identify the lithology of the formation. It mainly divides the anomalies based on the characteristics that the lithology and fluid type anomalies of different reservoirs occupy different areas on the intersection graph plane. . Commonly used are neutron-density crossplot, sonic time differenc...

AI Technical Summary

Problems solved by technology

The disadvantage of these new methods is that the technical requirements are complicated, and even new logging methods are required

[0004] In addition, the previous logging lithology identification methods were mostly based on the differences in rock mineral composition and structure during the depositional period.

However, since karst breccia was formed during karst diagenesis, its compositional structure is complex, and it is different from sedimentary rocks formed by sedimentation or igneous rocks formed by magma, so it is difficult to identify karst breccias with traditional lithology identification methods. rock identification

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