The Open Petroleum Engineering Journal

2014, 7 : 119-124
Published online 2014 December 31. DOI: 10.2174/1874834101407010119
Publisher ID: TOPEJ-7-119

Improved Prediction Model for Determining the Lost Gas Content of Extreme-soft and Outburst-prone Coal Seam

Xu Dong-fang , Feng Tao , Qin Zuo-ya and Yang Jing
Central South University/ Hunan Provincial Coal Science Research Institute, Hunan Changsha 410004, China.

ABSTRACT

Few study has been carried out on the desorption rules of extreme-soft and outburst-prone coal in south of China, especially coal from Hunan Province of which the value of “f” is normally less than 0.2. Desorption experiments are conducted on the coal samples from Hongwei and Jiahe Mines in Hunan Province, and the following phenomena can be observed: the calculating mean error by √t method and power function method of Hongwei coal samples are 29.68% and 68.33%, 28.55% and 70.28% of Jiahe , the calculating result by the two methods is always lower. After comparison we find that the √t method is more precise than power function method, so calculation method is improved based on √t method, mean error of gas content determination by the new method in experiment and coal mine are 6.88% and 5.24%, both less than 10%.

Keywords:

√t method, extreme-soft, improved √t method, lost gas content, outburst-prone coal seam, power function method.