摘要
油井爆生气体对岩石劈裂作用过程,是裂缝面对动态荷载响应并使其发生动态扩展的过程。为描述裂缝动态扩展过程,在气体劈裂过程各能量平衡关系式中,引入动能增量。而动能增量可由量纲分析法推导的能反映裂缝扩展速度和加载率影响的计算公式表示。在离散时间域内,特定气体劈裂作用下,能量方程迭代求解可得到裂缝扩展速度及裂缝扩展长度。由算例分析可知,虽然气体升压变缓时裂尖动态响应对裂缝扩展影响有减弱的趋势,但在气体压力升压较缓情况下,裂尖动态响应对裂缝扩展结果影响仍然很显著。
During fracture propagation driven by detonation gas m Oil well, dynamic response of crack surface under the gas pressure results in fast fracturing. In order to simulate the dynamic fracture process, kinetic energy is introduced into the equation of energy balance to describe the energy relationship during fracture propagation driven by gas pressure. Here, an approximate formula educed by dimensional analysis is presented, which involves fracture velocity and loading rate, to calculate kinetic energy increment. Thus fracture velocity and length can be obtained by iterative solution of energy balance equation in every time step when loading rate is given. In the case study, the results show that when gas pressure rising rate becomes slow, the dynamic response of crack tip to crack development will become weak. So it is obvious that dynamic response greatly influences the ultimate fracture length.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2006年第11期2369-2372,共4页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金(0479023)2004年高等学校博士学科点专项科研资助项目(20040700001)
关键词
岩石力学
爆生气体
能量平衡
动态响应
裂缝扩展
rock mechanics
detonation gas
energy balance
dynamic response
fracture propagation
