Cbm Fracturing Simulation Study

With the rapid development of economy, energy has become tighter. As an emerging clean energy, coal-bed methane which is abundant has drawn wide attention. China is a country rich in coal, whose coal-bed methane reserves is the second biggest in the world, and the volume of shallow coal-bed methane is equal to natural gas, which is account for 13% of the total coal-bed methane resources in the world. The development and utilization of coal-bed methane has a broad prospect which is important to reduce the accidents, protect the atmospheric environment and ease the insufficient energy supplies.In this paper, based on coal-bed methane fracturing at home and abroad, the trend for development of coal-bed methane well is mastered. Systemic utilized the knowledge of fluid mechanics, linear elastic fracture mechanics, heat conduction, computing mathematics, and further study of the fracturing design models and methods, including an extension of cracks in three-dimensional model, numerical model of temperature and parameters acquisition of the fracturing. The following achievements are obtained:(1) Researching and analysis of fracturing literature about Coal-bed methane wells is completed, and mastering the trend for development of coal-bed methane well.(2) Developing the three dimensional extension model in complicated conditions. The model takes into account the multi-layered and heterogeneity characteristics, which can simulate any thickness of multi-layer, and impact of thickness, stress and rock mechanics parameters (such as Poisson's ratio, elastic modulus, rock fracture toughness) upon the model. This model is suitable to any kind of stress distribution and the condition of coal seam during extending.(3) Studied the three dimensional extension model which considers the effect of elastic deformation and the water power of scouring. Using fluid mechanics, rock mechanics and other related theories to make a water power of scouring mechanism analysis of.(4) Exploring the acquisition Fracturing parameters, collecting the experimental results of Young's modulus, Poisson's ratio and the level of minimum principal stress about coal, and processing the data, which are great significant to understand the characteristics of coal.(5) A practical example proves that the model and procedure are cogent and effective which can meet the needs of coal seam fracturing.