摘要
赋存深度对页岩储层岩石力学特性具有显著影响。研究深层页岩的形变破坏机理,获得赋存深度对岩石力学参数的影响规律,能够为页岩油气开发提供至关重要的基础参数。采用不同深度页岩岩样系统开展了岩石力学实验,分析了深层页岩的关键力学性质,得到了其强度参数及形变模量的变化规律。结果表明:深层页岩在力学强度、抗形变破坏能力、破裂方式等方面与浅层页岩有显著差异,深度增加时,页岩强度逐渐提高,脆性表现逐渐变差,压裂改造难度也显著提升;绝大多数岩石力学参数均随围压的升高而得到强化,围压、密度等是影响深层页岩力学表现的关键因素;深层页岩力学性质的改变对压裂裂缝起裂、转向等力学行为均具有明显影响,深层页岩的造缝能力随赋存深度的增加而逐渐降低。研究成果可为深层页岩油气藏的评价和钻完井实践提供重要参考和理论依据。
The occurrence depth has a significant effect on the rock mechanical properties of shale reservoir.The deformation and failure mechanism of deep shale was studied to obtain the law of the effect of occurrence depth on the rock mechanical parameters and provide crucial basic parameters for shale oil and gas development.Rock mechanics experiments were conducted with shale rock samples at different depths to analyze the key mechanical properties of deep shale were analyzed and obtain the variation law of its strength parameters and deformation modulus.The results showed that deep shale was significantly different from shallow shale in terms of mechanical strength,resistance to deformation and failure,and fracture mode.With the increase of depth,the strength of the shale gradually increases and the brittleness gradually deteriorates,leading to more difficulties in fracturing stimulation.Most rock mechanical parameters were strengthened with the increase of confining pressure.Confining pressure,density,etc.are the key factors affecting the mechanical performance of deep shale.Changes in the mechanical properties of deep shale greatly affect the initiation,turning and other mechanical behavior of fracturing fractures.The fracture generation capability of deep shale gradually decreases with the increase of the occurrence depth.The research results provide important reference and theoretical basis for the evaluation of deep shale reservoirs and the practice of drilling and completion.
作者
李庆辉
李少轩
刘伟洲
Li Qinghui;Li Shaoxuan;Liu Weizhou(Shenzhen Qianhai Energy Technology Development Co.,Ltd.,Shenzhen,Guangdong 518000,China;Xidian University,Xi′an,Shaanxi 710126,China;PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2021年第3期130-138,共9页
Special Oil & Gas Reservoirs
基金
中海石油(中国)有限公司“十三五”重点项目“南海西部油田上产2000万方关键技术研究”(CNOOC-KJ 135 ZDXM 38 ZJ)。
关键词
页岩气
岩石力学
储层改造
破裂方式
裂缝扩展
深层页岩
shale gas
rock mechanics
reservoir stimulation
fracture mode
fracture propagation
deep shale