Optimization of Coalbed Methane Gathering System in China

Abstract

Because of the increasing energy demand, coalbed methane (CBM) which is a high-quality, clean new energy gets more and more national attention. As one of the keys of CBM's successful development, the investment of surface gathering system accounts for a significant proportion of the entire field's investment. This paper studied the optimization of CBM gathering system, combined with system process characteristics and the status of extraction and production. We chose a phased optimization method such that the optimization of entire system was divided into several subproblems, including well group's optimal partition, determination of gathering valve set's optimal position, optimization of trunk and branch pipe network's layout, and optimization of pipe diameter. Then we established optimization model such that the least investment costs of each stage were to be as objective function. When solving the model, full consideration of the low pressure and high complexity by which the CBM gathering and transportation pipeline network was characterized should be given. Through an example calculation, compared with artificial design result, the total investment decreased by 9.56%. We proved that the method has a good optimization effect by comparably analyzing the investment and construction scale of the existing pipe network and optimal pipe network.