摘要
为了研究脉动参量对脉动水力压裂致裂效果的影响,制作了力学特征接近真实煤体的型煤试样,利用脉动水力压裂实验系统分别从不同压裂方式、不同脉动频率和不同参量组合3个方面进行了实验,实验结果表明:对于相似型煤试样,脉动压裂在较小压力下使试样破坏,其原因在于使试样产生疲劳破坏;脉动压裂时试样内部变化可分成脉动水充满原始裂隙、裂隙发育和扩展、裂隙贯通3个时期;相同压力下,脉动频率越低裂隙发育越充分,脉动频率选择24 Hz时煤层增透效果和脉动压裂效率均能得到保证;实施脉动水力压裂时应适当控制脉动压力,为脉动水在煤体内部的反复作用提供时间保证。结合脉动参量组合特点,提出了"双频-双压"压裂工艺。
In order to study the influence of pulsating parameters to fracturing effect by pulse hydraulic fracturing, coal briquette samples that the mechanical characteristics closed to the real were done, and experiments were taken in three aspects included different fracturing mode and pulsating frequency and parameters＇ combinations by pulse hydraulic fracturing system. The results show that to the similar briquettes ted under low pressure, for which can make sample fatigue sample pulse fracturing can make the sample destruc damage The process of sample internal changes can be di vided into three periods which calls pulsating water is full of original fissures, fissures propagation and extension, and fissures connectivity. Under the same pressure, the lower pulse frequency is, the more fissures are, and 24 Hz is select ed as the pulsating frequency that meets the need of coal antireflection but also the fracturing efficiency can be guaran teed. The pulsating pressure should be controlled properly so that it can provide sufficient time for the pulsating water at the coal inside repeated when pulse hydraulic fracturing is implemented. Based on the characteristics of pulse pa rameters combination ＂dual frequencydual pressure＂ fracturing technology is proposed.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2013年第7期1185-1190,共6页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2011CB201205)
国家自然科学基金面上资助项目(51274195)
江苏省自然科学基金面上资助项目(BK2012571)
关键词
脉动水力压裂
脉动频率
脉动压力
参量组合
疲劳破坏
增透
pulse hydraulic fracturing
pulsating frequency
pulsating pressure
parameters＇ combination
fatigue dam-age
antireflection
