Tight reservoir volume pressure crack network extension simulation and representation method

Abstract

The invention discloses a tight reservoir volume pressure crack network extension simulation and representation method. The method comprises the following steps of: firstly establishing a multi-crackstress interference-considered tight reservoir combined ground stress field calculation model by utilizing a displacement discontinuity method, mechanical mechanism analysis and crack initiation and extension criterions; aiming at a stress interference problem in volume pressure crack multi-crack extension process, establishing flow pressure drop distribution models, in primary and secondary cracks, of a fracturing fluid, so as to form a tight reservoir volume pressure crack horizontal well crack network extension theoretical model; and finally comprehensively analyzing influences, on volume pressure crack network structural morphology, of different factors, and defining a plurality of feature parameters to represent crack network structure morphology and attribute features. At last, the tight reservoir volume pressure crack network extension simulation and representation method is established. The tight reservoir volume pressure crack network extension simulation and representation method has the advantages of being comprehensive in model factor consideration, high in simulation effect and visual in result, and has a certain guiding significance for optimum design and efficient development of tight reservoir cracks.

Description

technical field [0001] The invention relates to the field of oil well development, in particular to a method for simulating and characterizing expansion of volumetric fracturing fracture networks in tight reservoirs. Background technique [0002] Due to the strong brittleness of the continental tight reservoirs in the Ordos Basin in western my country, natural fractures are generally developed. The associated natural fractures in tight reservoirs and the artificial network fractures produced by volume fracturing together constitute an extremely complex multi-porous media network system, which affects the development effect of oil wells. At present, the recovery rate of volumetric fracturing well depletion in tight reservoirs in the Ordos Basin is generally low, and there are problems such as serious channeling of injected water and low degree of water driving during water injection development. The fundamental reason lies in the formation mechanism of complex fracture networ...

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Problems solved by technology

[0027] In order to overcome the defects of the above-mentioned prior art, the object of the present invention is to provide a tight reservoir volumetric fracturing fracture network expansion simulation and characterization method, to deal with problems such as the development of natural fractures in tight reservoirs and the interference of multiple fractures in fracturing, using the improved Displacement discontinuity method, mechanical mechanism analysis of propagation mode and criterion of fracture initiation and propagation, establish a theoretical model of volume fracturing fracture network expansion in tight reservoirs, simulate the formation process of volume fracturing fracture network in tight reservoirs, and analyze in-situ stress field, fracture propagation mode and branches The change law of fracture propagation angle and pressure reveals the law and mechanical mechanism of volume fracturing fracture propagation in tight reservoirs, obtains different fracture network stimulation modes of volume fracturing horizontal wells, and describes the structure and parameters of complex fracture network multiple pore media , which has the advantages of comprehensive consideration of model factors, high simulation efficiency and visualization of results.

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