Open Access

ARTICLE

Adaptability Evaluation of Coal-bed Methane Well Completion Methods Based on Multi-objective Decision-making Method

Gang Yang¹, Zhiming Wang²
1 MOE Key Laboratory of Petroleum Engineering , China University of Petroleum, Beijing, China.
2 Corresponding author, Zhiming Wang, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum (Beijing), 18 Fuxue Road, Changping District, Beijing, 102249, China. Email: wellcompletion@126.com.

Structural Longevity 2013, 9(3), 153-168. https://doi.org/10.3970/sl.2013.009.153

Abstract

Coalbed methane (CBM) is an important natural gas resource, and appropriate well completion method is very important to increase productivity. At present there are many CBM well completion methods, including fractured vertical well, open-hole cavity well, U-shape well, V-shape well and pinnate horizontal well. Aim at the diversity of CBM well completion methods, multi-objective decision-making method is used to evaluate these completion methods and select the best completion to maximize economic benefit. Firstly implements production prediction and economic evaluation for each completion method, and then chooses multi-objective decision-making method to evaluate five indexes: cumulative gas production, net present value, invest recovery period, internal rate of return and risk factor, thus the most appropriate completion method can be achieved.
With this evaluation method applied to Ordos Basin, numerical simulation results show that pinnate horizontal well predominate in the beginning of exploitation compared with other completion methods, and its advantages dwindle due to limited reservoir supply capacity in the latter period. In spite of its huge investment and high risk, with high productivity, its NPV far overweighs other completion methods, so the pinnate horizontal well is the most suitable completion method. The adaptability evaluation method proposed provides favorable guidance for on-site CBM well completion method design, which has a great significance to improve China’s CBM development effect.

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Keywords

Well completion methods, Production prediction, Economic evaluation, Multi-objective decision-making method.

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