古城区块煤岩压裂裂缝扩展规律实验研究

发布时间：2018-06-14 08:04

本文选题：古城区块 + 地质特征　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：煤层气是与煤炭伴生的一种清洁能源气体,以甲烷为主要成分赋存在煤层中,其中90%左右是吸附于煤基质孔隙裂隙表面,10%左右游离于孔隙裂隙之间。我国煤层气资源储量约为36.8万亿立方米,位居世界第三位,与天然气的储量相当。煤层气作为一种新兴的非常重要的非常规天然气,越来越受到重视。然而华北油田煤层气公司在沁水盆地的煤层气开发效果并不理想,压裂施工效果有好有坏。因此就需要在煤岩破裂力学机制、适应性的压裂施工工艺参数以及缝网发展控制因素等方面进行更深入的研究。本文以沁水盆地古城区块的煤层气水力压裂改造工程为背景,在收集区块基础资料、开展煤岩结构及力学特性实验研究的基础上,综合煤岩结构及力学特性分析、三轴水力压裂物理模拟实验等手段,研究分析古城区块煤层气产层力学特性,原始地应力,煤岩压裂裂缝扩展规律及裂缝起裂扩展主要影响因素。实验表明,煤岩天然裂缝和割理发育,直接影响水力压裂裂缝起裂方向及裂缝形态,并大大减弱地应力对压裂裂缝的影响效果;射孔沟通了射孔眼之间的孔隙、裂隙,孔眼附近应力场发生改变,压裂裂缝优先选择天然裂缝和割理面方向起裂,并相互沟通;地应力对煤岩压裂裂缝的影响效果更复杂,大大区别于常规储层,根据常规储层所建立模型得出的地应力影响规律不能适应于煤储层。最后,在物理模拟实验结果分析基础上,结合现场施工情况,对古城区块煤层压裂裂缝起裂扩展主控因素进行了总结分析,研究结果为古城区块水力压裂施工参数优化设计提供了一定的基础理论依据。
[Abstract]:Coal bed methane (CBM) is a kind of clean energy gas associated with coal. Methane is the main component in coal bed, 90% of which is adsorbed on the surface of pore fissure of coal matrix, about 10% of which is free between pores and fissures. The reserves of coalbed methane in China are about 36.8 trillion cubic meters, ranking third in the world and equivalent to the reserves of natural gas. As a new and very important unconventional natural gas, coalbed methane (CBM) has been paid more and more attention. However, the coalbed methane development effect of Huabei Oilfield Coalbed methane Company in Qinshui Basin is not ideal, and the fracturing effect is good and bad. Therefore, it is necessary to further study the fracture mechanics mechanism of coal and rock, the parameters of adaptive fracturing process and the controlling factors of fracture network development. Based on the hydraulic fracturing engineering of coalbed methane in the ancient urban block of Qinshui Basin, this paper, on the basis of collecting the basic data of the block and carrying out the experimental study on the structure and mechanical properties of coal and rock, synthesizes the analysis of the structure and mechanical properties of coal and rock. By means of physical simulation experiment of triaxial hydraulic fracturing, the mechanical characteristics, original ground stress, fracture propagation law of coal and rock fracturing and the main factors affecting fracture initiation in Gucheng block are studied and analyzed. The experiment shows that the natural fracture and cleat development of coal and rock directly affect the fracture initiation direction and fracture morphology of hydraulic fracturing fracture, and greatly weaken the effect of in-situ stress on fracturing fracture. The stress field in the vicinity of the pore is changed, the fracturing fracture preferentially chooses the natural fracture and the fracture plane to start the fracture, and communicates with each other, the effect of in-situ stress on the fracture of coal and rock fracturing is more complicated, and it is greatly different from the conventional reservoir. According to the model established by conventional reservoir, the law of ground stress influence can not be adapted to coal reservoir. Finally, on the basis of the analysis of the results of the physical simulation experiments and combined with the field operation, the main control factors of fracture initiation and expansion of coal seam in Gucheng block are summarized and analyzed. The results provide some basic theoretical basis for the optimization design of hydraulic fracturing operation parameters in Gucheng block.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE377

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