A systematic and focused engineering approach for production optimization and reservoir management of Coal Bed Methane field developments is discussed. Such an approach constitutes a decision making tool for production optimization of CBM fields.

The paper briefly discusses the dynamics of the reservoir/production mechanisms, dewatering, desorption, fracturing mechanics and damage mechanisms affecting fracture conductivity and methane production. We present a set of best completion practices for CBM field ranging from reservoir behavior of CBM reservoirs, formation evaluation applications, reservoir modeling, production analysis, perforating for fracturing and completion design and optimization.

An integrated reservoir description is incorporated into the completion strategies by the development and use of a Geomechanical model that accounts for the reservoir characterization and mechanical properties (pore pressures, k, ϕ, saturations, coal quality, stress gradients, stress contrast, Young's modulus, Poisson's ratios). The approach results in an efficient design and optimum placement of hydraulic fracture stimulation treatments and provides the strategy for high grading the coal quality and selective stimulation of the coal seams.

A robust methodology for analysis of commingled production data is performed using historical production data and advanced diagnostic procedures that match and predict performance to accurately estimate reservoir potential, well deliverability and completion efficiency. The unique procedures combine superposition-in-time with rate-transient analytic solutions for finite-conductivity vertically fractured and non-fractured wells to accurately determine effective properties. Simulation scenarios are created using a CBM simulator and used for optimizing reservoir/field development scenarios to accelerate the dewatering process and increase production by selective stimulation / completion criteria.

The optimization process can effectively improve field performance and economics and can be continuously improved according to the evolving needs of the economics of the reservoir development.

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