Research on the Application of Nuclear Magnetic Resonance Technology in the Evaluation of Fracturing Effect of Coalbed Methane Wells
Authors: Zhang, Wei; Li, Yang; Wang, Jun; Liu, Hong
Nuclear magnetic resonance (NMR) technology has been widely used in the evaluation of coalbed methane (CBM) reservoirs. This paper focuses on the application of NMR technology in the evaluation of fracturing effect of CBM wells. Based on the analysis of NMR relaxation mechanisms, the T2 spectrum characteristics of coal samples before and after hydraulic fracturing are studied. The results show that NMR T2 spectrum can effectively reflect the development of fractures and the change of pore structure. The fractal dimension of T2 spectrum is introduced to quantitatively characterize the complexity of fractures. Combined with the production data, the relationship between NMR parameters and gas production is established. The research provides a reliable method for the evaluation of fracturing effect and the optimization of fracturing design in CBM wells.