Judgment method for fracture diverting capacity of tight reservoir of oil and gas well

Abstract

The invention discloses a judgment method for fracture diverting capacity of a tight reservoir of an oil and gas well. The method comprises the steps of 1) selecting four factors including an initialfracture dip angle, a ground stress deviation, rock fracture toughness and a fluid pressure, performing orthogonal test scheme design, and taking the factors as different input parameters; 2) taking the parameters as the input parameters, and simulating a diverted fracture expansion path by utilizing an extended finite element unit method; 3) according to the diverted fracture path in the step 2),calculating a corresponding fracture angle; 4) performing normalization processing on the four factors; 5) building a diverting capacity evaluation model, wherein a diverting capacity index DI is a sum of the four normalized factors; 6) judging the diverting capacity; and 7) drawing a curve between the fracture diverting capacity index DI and the corresponding fracture angle in the step 3). The fracture diverting capacity of the tight reservoir can be quickly and accurately obtained, and an indoor large physical modeling test does not need to be carried out, so that the test expense is reduced.

Description

technical field [0001] The invention belongs to the field of hydraulic fracturing in petroleum and natural gas engineering, and in particular relates to a method for judging the steering ability of fractures in tight reservoirs of oil and gas wells. Background technique [0002] Reservoir matrixes such as shale oil and gas and tight oil and gas have low permeability, and complex fracture networks must be formed through volume fracturing technology for efficient development. Steering fracturing is an important means to enhance the expansion and control of fracture network. When objective factors such as local stress difference are not conducive to fracture diversion, artificial additional shielding can be introduced through temporary plugging diverting agent to seal previously formed fractures and high-permeability channels. It is used for controlled steering fracturing, improving the scope and effect of stimulation. [0003] Zhou et al. used the formation temperature automa...

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Problems solved by technology

[0004] Determining the diversion ability of reservoir fractures can provide a basic criterion for diversion fracturing stimulation. At present, there is no effective method to judge the diversion ability of tight reservoir fractures.

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