Optimization of the evaluation indexes of coalbed methane gas extraction

Abstract

The extraction procedure of coalbed methane is usually different from conventional type of gas extraction. Generally, the CBM extraction procedure is completed within two approaches. First one is drilling on the surface for heading downward through the ground & second one is extracting through the existed underground coal mines. For making the CBM extraction an economic viable, well optimization development should be implemented with carefully. So, an evaluative technique called ‘Unit Technical Cost’ briefly known as UTC can be one of the better way to evaluate the well optimization development. This optimization technique is evaluated practically based on the two major coal basins of china, known as ‘Qinshui basin & Ordos Eastern Margin basin’. The well completion & simulation process can be examined by the parameters that are used in this technique. This paper is tried to give a new research on CBM well development based on using the UTC method for making decision criteria to calculate the optimization level. The calculation is done using the detailed properties of UTC in the well development by establishing the process theory. In this research, the production profiles are evaluated for building up the engineering & geologic parameters where the product price, operating cost & project investment is evaluated for finding the economic parameters. This is found from the optimized results that a horizontal well should be optimized for its economic feasibility in the Qinshui Basin where directional well optimization is better for Ordos Eastern Margin Basin.

Keywords: Well optimization, well completion, unit technical cost, technical evaluation, evaluation index