页岩油气高效开发中的基础理论与关键力学问题

Fundamental Theory and Key Mechanical Problems of Shale Oil Gas Effective Extraction

我国页岩油气开发刚刚起步,许多基础理论和关键科学(力学)问题亟需明确和解决.本文按页岩油气开发的全过程自然地将其分为四个相互关联的科学问题展开介绍和讨论,包括:页岩工程地质力学特征与预测理论,地质力学找到气;多重耦合下的页岩油气安全钻井完井理论,钻井完井够到气;页岩地层动态随机裂缝控制机理与新概念压裂理论,体积压裂释放气;页岩油气多尺度渗流特征与开采理论,解吸运移产出气.本文提出用水力压裂创造页岩传气能力,用气体二次压裂页岩基质来解决气源问题,实现水力压裂创造的页岩传气能力与页岩基质气体供应能力相匹配,避免"断气"现象发生,最终达到页岩气可持续性开采.解决这些关键科学(力学)问题可以为页岩油气高效开发奠定可靠的基础,具有重要的理论意义和应用前景.

The shale oil gas extraction is just beginning in China. Many of fundamental theories and key scientific（mechanical） problems should be clarified and addressed. In this paper, the whole process of shale oil gas extraction was naturally divided into four interrelated sections and discussed in detail： the mechanical characteristics of engineering geology and prediction theory of shale for finding shale oil gas; multiplicity coupling safety and quality well drilling theory for exposing to shale oil gas; dynamic random crack control mechanism for the shale layers and a novel concept hydraulic fracturing theory for gas release; multiscale permeability characteristic and production theory for the shale oil gas transfer. In order to achieve the goal of effective and sustainable extraction, a novel research concept of compatibility between the flow capacity in shale and the gas supply from matrixes was proposed to avoid the ＂no gas supply＂ phenomena. Solving these key fundamental scientific（mechanical） problems could lay a reliable foundation for the efficient extraction of shale oil gas, which is both theoretically and practically significant.