A physical modeling test method for fracture initiation conditions and extension laws of branch fractures in vertical well multi-branch fracture fracturing

Abstract

The invention relates to the technical field of oil production engineering, in particular to a physical model test method for fracture initiation conditions and extension laws of branch fractures in multi-branch fracture fracturing of vertical wells. It mainly solves the problem that existing methods cannot systematically, quantitatively and accurately determine the initiation conditions and extension laws of branch fractures in multi-branch fracturing of vertical wells. In the present invention, firstly, the geological conditions for generating branch fractures are determined by observing the rock core photos taken out after the test under the condition of different horizontal stress differences. Then, by analyzing the mechanical data of the branch joint test, the engineering conditions for the branch joint production are determined. Finally, analyze the relationship between the branch crack initiation point, crack initiation angle and turning radius with the horizontal stress difference in the branch seam test, and determine the branch seam extension rule. The invention has the advantages of being able to systematically, quantitatively and accurately determine the crack initiation conditions and extension rules of branch fractures in vertical well multi-branch fracture fracturing.

Description

Technical field: [0001] The present invention relates to the field of oil production engineering, and in particular, there is a trial of a co-fracture condition and an extended regulatory material die test method involving a multi-branch seam fracturing branch. Background technique: [0002] Oilfield straight well multi-branch fracture, temporarily blocking the fracturing branch sewing geological conditions are still unclear; the engineering conditions are only derived in accordance with the rock mechanics formula, and the main sewing process is not taken into account. Side produces a weak surface or micro-crack; branch seam extension, only studies the fracture point of the branch seam, the cracking angle with the variation of the level of the level, the variation of the steering radius of the branch is still unclear. Branch seam cracking conditions, extension of the system, quantization, accuracy, leading to the application of process applicability, calendering optimization desi...

AI Technical Summary

Problems solved by technology

[0002] The geological conditions for fracturing of multi-branch fractures in oilfield vertical wells, temporary plugging and diversion to fracturing branch fractures are still unclear; The influence of the weak surface or micro-cracks on the side; the extension law of branch fractures, only the change law of the crack initiation point and angle of branch fractures with the horizontal stress difference is studied, and the change law of the turning radius of branch fractures is not clear

There is no systematic, quantified, and accurate understanding of the initiation conditions and extension laws of branch fractures, resulting in unclear understanding of process applicability, lack of theoretical support for fracturing optimization design, and difficulty in judging whether the process is successful and whether the fracture is diverted.

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