页岩脆性的表征方法及主控因素

Characterization method and main controlling factors of shale brittleness

王乔 李虎 刘廷 李志刚 董玉洁 蒋炳坤2

吉林大学博物馆，吉林 长春 130000 中国石油塔里木油田分公司，新疆 库尔勒 841000 中国石油新疆油田分公司油气储运公司，新疆 昌吉 831100

Jilin University Museum, Changchun 130000, China Tarim Oilfield Company, PetroChina, Korla 841000, China Oil and Gas Storage and Transportation Branch, Xinjiang Oilfield Company, PetroChina, Changji 831100, China

页岩脆性的表征在工程“甜点”优选以及勘探风险评估等方面具有重要的指导意义，文中对国内外近年来的页岩脆性表征方法和主要控制因素进行了综合分析和探讨。研究表明：页岩脆性评价方法主要基于岩石的应力￣应变关系和脆性矿物。脆性主控因素分为内在因素和外在因素，内在因素包括脆性矿物、有机质的成熟度、天然裂缝、层理、孔隙度、吸附作用，外部因素包括埋深以及水平地应力差，这些因素控制着岩石的应力￣应变关系，以及强度、能量、弹性模量等力学性质。文中提出未来应开发裂缝演化的动态可视化技术，搭建多种地质因素的数学评价模型，确定脆￣延性转换带的埋深界限，采用新型环保的无水压裂介质等建议。

The characterization of shale brittleness is of great significance to the optimization of engineering "sweet spot" and the risk assessment of exploration. In this paper, shale brittleness characterization methods and main control factors in China and abroad in recent years were comprehensively analyzed and discussed. The results show that the evaluation method of shale brittleness is mainly based on the stress-strain relationship of rock and brittle minerals. The main controlling factors of brittleness are internal factors and external factors. The internal factors include brittle minerals, organic matter and maturity, natural fractures, bedding, porosity and adsorption, while the external factors include burial depth and horizontal stress difference. These factors control the stress-strain relationship, as well as mechanical properties such as strength, energy, and elastic modulus. Some suggestions were put forward, such as developing dynamic visualization technology of fracture evolution, building mathematical evaluation model of various geological factors, defining the lower limit of burial depth of brittle-ductile transition zone, and adopting new environmental protection anhydrous fracturing media.

10.6056/dkyqt202004010