Prediction method and device for temporary plugging diversion crack

Abstract

The invention discloses a method and a device for predicting a temporary plugging diversion crack, as shown in Figure 1. The method comprises the following steps: collecting basic parameters required by calculation; a hydraulic fracture induced stress field model is established through a displacement discontinuity method, and displacement and stress components of any position are calculated; calculating induced stress generated by the hydraulic fracture and the formation fluid pressure change, and superposing the in-situ stress and the induced stress generated by the hydraulic fracture and the formation fluid pressure change to obtain a temporary plugging fracture wall surface stress distribution parameter; the plugging friction strength and the plugging shear strength of a temporary plugging wall formed by the temporary plugging agent are calculated, and the smaller value of the plugging friction strength and the plugging shear strength is selected as the pressure bearing capacity strength of the temporary plugging agent; and calculating the circumferential stress of the temporary plugging crack, comparing the circumferential stress of the temporary plugging crack with the limit circumferential stress, and predicting the temporary plugging turning crack. The method can be used for researching the technical principle of temporary plugging crack steering, simulating the temporary plugging crack expansion track of a typical fractured well group, and optimizing cracks and construction parameters.

Description

technical field [0001] The invention relates to the field of petroleum and natural gas engineering, in particular to a prediction method and device for temporarily plugging diversion fractures. Background technique [0002] Refracturing is one of the commonly used stimulation techniques for low-permeability oil and gas reservoirs. Refracturing the oil and gas layers that have been fractured increases the complexity of the fracture network and increases the drainage area. Due to the serious heterogeneity of low-permeability reservoirs and the strong heterogeneity of interlayer permeability, conventional refracturing only extends the original old fractures, and the oil recovery degree in the oil drainage area controlled by the fractures is high, but the oil drainage A large amount of remaining oil outside the area has a low degree of production, and the effect of increasing oil production is poor. Temporary plugging and diversion fracturing technology is a relatively new me...

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Problems solved by technology

[0004] However, the mechanism of the influence of this fracturing process on the diversion law of hydraulic fractures is not yet clear. The current research mainly focuses on the construction technology of temporary plugging and diversion fracturing, the selection of plugging agent materials, and the trajectory of diversion fracturing fractures. There are few studies on the mechanism of fracture initiation, which reduces the success rate of branch fracture fracturing

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