Method and system for measuring invasion depth of drilling fluid filtrate in reservoir

Abstract

The invention relates to a method and a system for measuring the invasion depth of a drilling fluid filtrate in a reservoir. The method comprises the following steps: measuring discrete filtration loss in a plurality of time segments; determining relevance between the time and the filtration loss through regression analysis; determining actual invasion volume of the drilling fluid filtrate according to the relevance between the time and the filtration loss; determining theoretical invasion volume according to drilling information; determining the invasion depth according to the actual invasion volume and the theoretical invasion volume. The system comprises a module for determining relevance between filtration loss and time, a module for determining actual invasion volume, a module for determining theoretical invasion volume and a module for determining invasion depth. The method and the system for measuring the invasion depth of the drilling fluid filtrate in the reservoir are simple and practical, and high in operability; in addition, compared with a permeability recovery value method in the prior art, the method has the advantages of excellent reproducibility and high reliability of judging results.

Description

technical field [0001] The invention belongs to the technical field of petroleum drilling, and relates to a method and a system for measuring the invasion depth of drilling fluid filtrate into a reservoir. Background technique [0002] In the process of oil drilling, the degree (depth) of drilling fluid filtrate invasion into the reservoir is directly related to the impact on the quality of the reservoir. At present, the method for evaluating the degree of reservoir invasion in the laboratory is mainly the permeability recovery value method, which is relatively simple and the reproducibility is not very good. The invasion depth of drilling fluid filtrate in the reservoir is an important parameter to reflect the reservoir protection effect of the drilling fluid system. At present, it can only be predicted by logging parameters, and there is no testing method to accurately determine the invasion depth of drilling fluid filtrate in the reservoir. Contents of the invention ...

AI Technical Summary

Problems solved by technology

At present, the method for evaluating the degree of reservoir invasion in the laboratory is mainly the permeability recovery value method, which is relatively simple and the reproducibility is not very good

The invasion depth of drilling fluid filtrate in the reservoir is an important parameter to reflect the reservoir protection effect of the drilling fluid system. At present, it can only be predicted by logging parameters, and there is no testing method to accurately determine the invasion depth of drilling fluid filtrate in the reservoir.

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