Prediction of Fracture Distribution in Shale Reservoirs in the Dingshan Area and Evaluation of Shale Gas Preservation Conditions

doi:10.3969/j.issn.1006-6535.2022.01.001

Abstract

Abstract: In response to the poor understanding of the fracture development and distribution and the influence of shale gas preservation conditions in Longmaxi Formation, Dingshan Area, the paleotectonic stress field in the study area was simulated through triaxial rock mechanics experiments, rock fracture coefficient was calculated by the Mohr-Coulomb criterion of rock failure, the fracture distribution pattern in the study area was predicted, and the favorable target area of shale gas exploration was optimized. The results showed that the areas with low differential stress and the areas developed with secondary or tertiary fractures were the dominant development areas for fracture development in the shale gas reservoirs, with good preservation effect. Based on the prediction results of fracture distribution, a preservation evaluation system and evaluation standards for Dingshan Area were established with the 12 selected evaluation parameters, and the study area was classified into two types of favorable areas by the weighting method and superposition method, and all of them have the characteristics of gentle tectonic positions, deep burial depth, low differential stress, far distance from large fractures, high pressure coefficient, small scale of fracture development, small dip angle, and early development period. The results of the study provide important reference for subsequent shale gas exploration and preservation condition evaluation.

Key words: shale reservoir, tectonic stress field simulation, fracture distribution prediction, shale gas, preservation conditions, Dingshan Area

CLC Number:

TE132.2

Xie Jiatong, Fu Xiaoping, Qin Qirong, Fan Cunhui, Ni Kai, Huang Manning. Prediction of Fracture Distribution in Shale Reservoirs in the Dingshan Area and Evaluation of Shale Gas Preservation Conditions[J]. Special Oil & Gas Reservoirs, 2022, 29(1): 1-9.

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