Application of Well Temperature Logging in Coalbed Methane Well Fracture Effectiveness Evaluation

Abstract:

Mature oil well temperature logging technique was applied to coalbed methane wells in order to monitor the fracture height and guide the fracturing and drainage. The results show that, after fracture treatment, fracture height was bigger than that of perforated interval, and mainly extended upward. In the case of 11^# coal seam in Taiyuan formation of Permian, Upper Palaeozoic, overlying K2 limestone were all cracked through, while in the case of 3^# and 5^# coal seam in Shanxi formation of Permian, Upper Palaeozoic, overlying sandstone section in some wells was cracked through. In the former case, the fracturing curve shows fracture pressure higher than 27MPa, pump off pressure higher than 20MPa, and high pressure dropping rate over 0.4MPa/min, while the fracture pressure lower than10MPa, pump off pressure lower than 5MPa and low pressure dropping rate that generally under 0.1MPa/min in the latter case. Fracture height is directly influenced by crustal stress of the rock cracked by fractures, and tends to become bigger with the increase of fracture pressure and pump off pressure. To achieve desired results after coalbed methane reservoir stimulation treatment, a restriction of fracture pressure during fracturing process is recommended to control fracture height.

• Periodical: Applied Mechanics and Materials (Volumes 522-524)
• Pages: 1522-1527
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.522-524.1522
• Online since: February 2014
• Authors: Xian Yue Xiong, Dai Yong Cao, Yun Tao Jiang, Li Heng Bian, Wei Wang, Lei Wang, Qi Liu
• Keywords: Coalbed Methane (CBM), Effect Evaluation, Fracture, Fracture Height, Well Temperature Logging

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