Influence of the Cluster Effect on the Fracture Connectivity

doi:10.3969/j.issn.1006-6535.2023.06.014

Abstract

Abstract: In response to the problem that it is necessary to fully consider the randomness and non-homogeneity of the fracture network layout due to the strong non-homogeneity and disordered and complex distribution of fractures of the fractured-vuggy reservoirs in Tahe Oilfield, the percolation theory was adopted to simplify the fracture network into a random and disordered system, and then the connectivity of fracture networks with the clustering behavior was investigated. The results show that as the fracture network transforms from isotropic to anisotropic, the connectivity increases and then decreases; the local clustering effect of the fracture network affects the percolation threshold, which decreases with the increase of the clustering effect, suggesting that the clustering effect can improve the local network connectivity but impair the overall connectivity. The method was applied in the development of Tahe unit A, and the unit recovery rate increased from 15.6% to 20.7%, and the new recoverable reserves were more than 42.1×10⁴t by formulating programs such as well network construction, well network flow potential adjustment, and oil displacement of well group through injection of nitrogen. This study is of great significance to the recovery enhancement of fractured-vuggy reservoirs in Tahe Oilfield.

Key words: percolation theory, fractal theory, clustering effect, fracture network connectivity

CLC Number:

TE355

Yuan Feiyu, Tang Chao, Zhang Chao, Fu Yafei, Chen Bo. Influence of the Cluster Effect on the Fracture Connectivity[J]. Special Oil & Gas Reservoirs, 2023, 30(6): 107-113.

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