Method for quickly identifying clastic rock reservoir based on two well log overlapped picture

Abstract

A method for quickly identifying a clastic rock reservoir based on a two well log overlapped picture includes the following steps that (1) according to a clastic rock stratum, an interval transit time parameter and a spontaneous potential parameter of the clastic rock stratum are obtained in a drilling hole through a logging instrument; (2) a relatively thick mud rock development section and a possible compact layer section are determined by referring to rock core or cutting logging data obtained through a special sampler in the drilling hole, and a mud rock base line is determined by combination with a spontaneous potential logging curve; (3) the spontaneous potential logging curve and an interval transit time curve are overlapped in the reverse direction according to a logging curve overlapping principle, and it is required that the two logging curves are basically overlapped on the mud rock base line portion and the compact layer section; (4) in the overlapped picture of the spontaneous potential logging curve and the interval transit time curve, an amplitude difference between the two curves on the separation portion of the two curves is determined according to the overlapping and separation relation between the two curves, and whether the storage physical property of the reservoir is good or not is judged according to the amplitude difference of the two curves. The method has the advantages of being easy and convenient to use, high in identification accuracy and high in 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 technolog...

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Problems solved by technology

[0002] With the continuous improvement of exploration and development, the complexity of geological targets and the difficulty of logging interpretation are also increasing, such as complex lithology sandstone, complex Double-porous medium reservoirs in pore structure reservoirs are constantly appearing, making it increasingly difficult to meet the needs of integration of exploration and development under complex geological conditions, which used to be the main basis for identifying lithology and evaluating reservoirs and logging interpretation technology. Misinterpretation of reservoirs as non-reservoirs during interpretation

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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