Identification method of sedimentary microfacies mode of carbonate rock high-frequency sequence framework

Abstract

The invention provides an identification method of a sedimentary microfacies mode of a carbonate rock high-frequency sequence framework. The method includes the following steps: determining a lithologic sensitive well logging curve by using a layer rock core sample of carbonate rock and a conventional well logging curve; determining a three-porosity well logging curve combination according to a resistivity well logging curve combination; identifying a low-frequency sequence boundary according to the lithologic sensitive well logging curve, the three-porosity well logging curve combination and the resistivity well logging curve combination; identifying a high-frequency sequence boundary according to the low-frequency sequence boundary; analyzing single well sedimentary subfacies and microfacies division; and completing the comparison and division of sedimentary microfacies of a whole well section. The method has strong operationality, conforms to the principles of sequence stratigraphy and sedimentology, can accurately establish the sedimentary microfacies mode with the high-frequency sequence as constraint with dynamic and static combination of division units, carries out sedimentary evolution analysis, and lays a good foundation for the sedimentary understanding of carbonate gas reservoir, the establishment of reservoir geophysical prediction forward model and the comprehensive evaluation of gas reservoirs.

Description

technical field [0001] The invention relates to the fields of oil and gas exploration and development, in particular to a method for identifying sedimentary microfacies patterns of high-frequency sequence frameworks of carbonate rocks. Background technique [0002] In recent years, the research work of carbonate microfacies analysis has attracted more and more attention and developed rapidly, and has become an indispensable content in the study of carbonate rocks. Many scholars have made important expositions on the study of carbonate rock microfacies. The term "microphase" was first proposed by Brown (1943). Flügel (2004) further defined sedimentary microfacies as the synthesis of all paleontological and sedimentological features that can be distinguished in thin sections, exfoliated sections, and polished sections, and carried out the Wilson (1975) carbonate-fringed platform model With appropriate corrections, 26 standard microfacies types were classified and classified ...

AI Technical Summary

Problems solved by technology

First of all, for the development stage of oil and gas reservoirs, under the constraints of five-level or six-level high-frequency sequence framework, there are few examples of more detailed vertical and horizontal correlation studies of sedimentary microfacies

Second, there are two kinds of depositional models: vertical sequence and lateral sequence. The depositional models of carbonate rocks are mostly horizontal and static, and there is no related research on the dynamic evolution process.

Third, the sedimentary models of continental clastic rocks in my country are relatively rich, complete and detailed, while marine carbonate rocks are less, and most of them focus on the strata of series, formations and members of the third-order sequence as the research unit The depositional model of the sedimentary facies (or sub-facies), while the microfacies depositional model with the five-level high-frequency sequence as the research unit is less, and it is often a single static depositional model, lacking the study of different high-frequency sequences. Dynamic Sedimentary Microfacies Model for Sedimentary Evolution Analysis

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