A method for rapid identification of clastic rock reservoirs based on the overlay of two logging curves

Abstract

A method for quickly identifying clastic rock reservoirs based on two kinds of well logging curve overlapping graphs, comprising the following steps: first, aiming at clastic rock formations, acquiring acoustic waves of clastic rock formations in boreholes by using logging instruments Second, refer to the core or cuttings logging data obtained by using a special sampler in the borehole to determine the relatively thick mudstone development interval and possible tight intervals, and combine the spontaneous potential measurement The mudstone baseline is determined by the well curve; thirdly, according to the principle of the log curve overlapping method, the spontaneous potential and the acoustic wave time difference curve are reversely overlapped, and the two logging curves are basically coincident in the mudstone baseline and tight layers; fourthly, In the overlay graph of the two logging curves of natural potential and acoustic wave time difference, according to the overlapping and separation relationship between the two curves, determine the amplitude difference between the two curves at the part where the two curves are separated, and according to the magnitude of the amplitude difference between the curves , to judge the relative good or bad of reservoir physical properties, which has the characteristics of simplicity, convenience, high recognition accuracy and fast speed.

Description

technical field [0001] The invention belongs to the technical field of geophysical well logging, and in particular relates to a method for quickly identifying clastic rock reservoirs based on two kinds of well logging curve overlapping graphs. Background technique [0002] With the continuous improvement of the degree of exploration and development, the complexity of geological targets and the difficulty of logging interpretation are also increasing. For example, complex lithology sandstone and dual-porosity medium reservoirs with complex pore structure appear continuously, which led to the As the main basis for identifying lithology and evaluating reservoirs and logging interpretation technology, it is increasingly difficult to meet the needs of integration of exploration and development under complex geological conditions. In the process of logging interpretation, reservoirs are misinterpreted as non-reservoirs. Phenomenon. However, there is no rapid evaluation technology...

AI Technical Summary

Problems solved by technology

[0002] With the continuous improvement of the degree of exploration and development, the complexity of geological targets and the difficulty of logging interpretation are also increasing. For example, complex lithology sandstone and dual-porosity medium reservoirs with complex pore structure appear continuously, which led to the As the main basis for identifying lithology and evaluating reservoirs and logging interpretation technology, it is increasingly difficult to meet the needs of integration of exploration and development under complex geological conditions. In the process of logging interpretation, reservoirs are misinterpreted as non-reservoirs. Phenomenon

However, there is no rapid evaluation technology for complex lithology and reservoir characteristics to select logging parameters and curve characteristics that are sensitive to lithology and physical properties, and then establish an interpretation model that is jointly constrained by geological-logging parameters. To improve the accuracy of reservoir rating

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