How to identify the best candidate fracturing zone: A review of current fracability evaluation method

• Published in: IOP conference series. Earth and environmental science 2021-10, Vol.861 (6), p.62071
• Main Authors: Huang, Z X, Yang, K, Peng, C Y, Ai, C Z, Jiang, M, Deng, J T, Liu, W J
• Format: Article
• Language: English
• Subjects: Evaluation; Fracture toughness; Geomechanics; Hydraulic fracturing; Methods; Oil reservoirs; Reservoirs
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/861/6/062071

Hydraulic fracturing has become an important stimulation method for unconventional oil/gas reservoirs to achieve industrial capacity. Fracability evaluation has become one of the most important step during the reservoir characterization and fracturing job design, which is beneficial for identifying the best candidate fracturing zone. In this paper, we provide a detailed review of the existing fracability evaluation methods. The evolution of the fracability evaluation method from the single-factor method, i.e. the brittleness method, to the multi-factor methods which incorporate brittleness, fracture toughness, in-situ stress as well as natural fracture parameters has been summarized. For the brittleness methods, different definitions of brittleness have been summarized and compared. For the multi-factor fracability evaluation methods, particular emphasis has been paid on illustrating how the factors were selected and incorporated into different fracability evaluation methods and possible field evidences validating the effectiveness of different fracability evaluation methods. In addition, the emerging 3D fracability evaluation attempts based on 3D seismic data and geomechanical analysis, which may serve as a guidance for finding the so-called engineering sweet spots, have been introduced in details. Finally, possible future work to improve the effectiveness of fracability evaluation is discussed.