Ultra-low permeability reservoir dominant seepage channel identifying and characterizing method

Abstract

The invention discloses an ultra-low permeability reservoir dominant seepage channel identifying and characterizing method. The method comprises the following steps of firstly, determining the material source direction of an oil production interval, the ancient riverway orientation, a sand body internal building structure and a single sand body rhythm type; determining micro-fracture parameters ofthe production interval, and constructing a three-dimensional fine geological model of a to-be-researched block; establishing a reservoir prediction model in the current development stage; establishing a four-dimensional reservoir underground streamline evolution model of the to-be-researched block, quantitatively evaluating the injection-production well communication relationship and the injection-production corresponding rate, and comprehensively identifying the position and the plane orientation of the dominant seepage channel between well groups; and quantitatively calculating the advancing speed of the water flooding front edge, the tracer agent interpretation swept volume, the tracer agent interpretation permeability and the Lorentz coefficient, screening static indexes and dynamicindexes capable of characterizing the strength of the seepage channel, and establishing an evaluation index system and defining parameters of the ultra-low permeability reservoir dominant seepage channel. According to the method, quantitative research on the three-dimensional space distribution rule of the channel provides guarantee for effective treatment of the extra / ultra-low permeability reservoir dominant seepage channel and improvement of the final recovery ratio of crude oil.

Description

technical field

[0001] The invention relates to an evaluation and identification technology for dominant seepage channels in ultra-low permeability reservoirs, in particular to an identification and characterization method for dominant seepage channels in ultra-low permeability reservoirs. Background technique

[0002] Water injection development is one of the main methods of oilfield development. The development of dominant channels inside the oil layer caused by the long-term scouring of injected water will cause inefficient and ineffective circulation of a large amount of injected water, resulting in a rapid increase in water cut in oil wells and a low degree of water driving in the reservoir, which seriously restricts the improvement of oil recovery. In particular, the Yanchang Formation and Yan'an Formation reservoirs in the Ordos Basin in my country have tight physical properties. Compared with loosely cemented medium-high permeability reservoirs, the development histo...

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