Planktonic foraminifera limestone rock classification method based on sedimentation and diagenesis description

Abstract

The invention provides a planktonic foraminifera limestone rock classification method based on sedimentation and diagenesis description. The method comprises the steps of (1) carrying out lithologic classification and diagenetic classification on planktonic foraminifera limestone rocks based on microscopic slices; (2) overlapping lithologic classification and diagenetic classification results to form composite classification, and merging data with the same porosity-permeability relationship in the composite classification to simplify classification; (3) carrying out mercury injection curve analysis and verification on the simplified classification, if the pore throat structure can be obviously distinguished according to the simplified classification, carrying out the step (4), and if the pore throat structure has no discrimination according to the simplified classification, carrying out simplified classification again; and (4) analyzing and verifying the oil content level of the core according to the simplified classification, if the oil content level can be obviously distinguished according to the simplified classification, completing the classification of the planktonic foraminifera limestone rock, and if the oil content level is not distinguished according to the simplified classification, carrying out simplified classification again.

Description

technical field [0001] The invention relates to a method for classifying planktonic foraminiferal limestone rocks based on sedimentation and diagenesis description, and belongs to the technical field of oilfield development geology. Background technique [0002] Planktonic foraminiferal limestone is a type of limestone with foraminiferal large body cavity pores and intermatrix micropores as the main pore spaces. The large body cavity pores are often disconnected, resulting in high porosity but extremely low permeability. Therefore, this type of reservoir generally has relatively high reserves, but it is difficult to produce due to the ultra-low permeability level. This type of limestone reservoir is a typical type of non-main reservoir in CNPC's overseas projects. At present, all blocks of overseas projects are in the stage of increasing and stabilizing production, and are facing problems such as heavy production capacity load of main oil reservoirs and difficulty in replaci...

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Problems solved by technology

[0008] 1) These methods are often based on bioclastic shoal reservoirs with connected pores, and the application of foraminiferal limestone with disconnected pores is doubtful, and the classification effect is often not good enough to meet the requirements;

[0009] 2) Only one type of data is often used, and the basis for dividing boundaries is not clear, and the classification results obtained are often difficult to have good application effects;

[0010] 3) Based on algorithms, lack of interpretation of geological origin, cannot be combined with sedimentation and diagenesis, and often have little significance in guiding reservoir distribution

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