Gas desorption characteristics effected by the pulsating hydraulic fracturing in coal
Gas desorption characteristics effected by the pulsating hydraulic fracturing in coal
复制标题
煤脉动水力压裂瓦斯解吸特性
DOI：
10.1016/j.fuel.2018.09.005
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发表时间：
2019-01-15
期刊：
影响因子：
7.4
通讯作者：
Sun Qian
中科院分区：
文献类型：
--
作者：
Ni Guanhua;Dong Kai;Sun Qian
为了阐明脉动压裂对瓦斯综合解吸的影响，开展了脉动水力压裂（PHF）和静态水力压裂（SHF）对瓦斯解吸特性影响的实验研究，考察了不同水力压裂方式下的瓦斯驱替量（GDA）和自然解吸量（NDA）。结果表明，静态水力压裂产生的瓦斯驱替量明显小于脉动水力压裂。同时，瓦斯驱替量随压裂频率先线性增加，后对数增加；随脉动峰值压力的增加呈对数增加。水对瓦斯的自然解吸有抑制作用。随着脉动压力和频率的增加，脉动压裂对瓦斯自然解吸的抑制作用减弱。根据不同压裂方式对瓦斯解吸的影响，将脉动水力压裂分为低压 - 低频、低压 - 高频、高压 - 低频和高压 - 高频四种类型。由于瓦斯驱替率（\(\eta_{(d)}\)）决定了瓦斯综合解吸效果的变化，低压 - 低频抑制瓦斯解吸，而低压 - 高频、高压 - 低频和高压 - 高频可促进瓦斯解吸。研究结果为优化脉动参数、增加瓦斯解吸和促进煤层瓦斯抽采提供了理论指导。
In order to clarify the effect of pulsating fracturing on gas comprehensive desorption, experimental study of gas desorption characteristics effected by the pulsating hydraulic fracturing (PHF) and static hydraulic fracturing (SHF) were carried out, the gas displacement amount (GDA) and natural desorption amount (NDA) under different hydraulic fracturing methods are investigated. The results show that the GDA generated by the SHF is significantly less than the PHF. At the same time, the GDA increases linearly first, and then logarithmically with the fracturing frequency; with the increase of pulsating peak pressure, it showed a logarithmic increase. The water has an inhibitory effect on the natural desorption of gas. With the increase of pulsating pressure and frequency, the effect of pulsation fracturing suppressing the natural desorption of gas is weakened. According to the effect of different fracturing methods on gas desorption, the PHF is divided into four types: low pressure-low frequency, low pressure-high frequency, high pressure-low frequency and high pressure-high frequency. Because the gas displacement rate (eta(d)) determines the changes of gas comprehensive desorption effect, the low pressure-low frequency inhibits gas desorption, while the low pressure-high frequency, high pressure-low frequency and high pressure-high frequency can promote gas desorption. The results provide theoretical guidance for optimizing pulsating parameters, increasing gas desorption and promoting coal seam gas drainage.