基于仿生结构诱导的裂缝防御机理及高时效自修复固井水泥体系的研究

The integrity and durability of oil well are critical for the safety mining of petroleum. However, the failure of interlayer isolation caused by cracking of cement sheath will lead to inter-porosity flow between formations, which severely threaten the cementing security. Recent researches were restricted to achieve the crack prevention in limited area and the closure of underground cracks. Therefore, it is of great prospect and economic significance to establish a comprehensive system, which can defense cracks in a wide range and induce effective self-healing. In this project, we explore the mechanism of micro-seismic structure by inducing the energy dissipation structure of oil well cement in a wide range; The crystallization activator is prepared by molecular designing, which prevents cement from totally hydrating, thus provides necessary conditions for the self-healing based on capillary crystalline. The deposition mechanism of the bionic structure of self-healing products is systematically studied and the multilayered tendon structured sodium alginate modified with carbon nanotube is introduced to achieve self-healing from structure to function. Our researches provide theoretical guidance and technical support for the development of self-healing cement system without manual intervention, so as to realize the high efficiency and intelligence of cementing technology.

油井的完整性和耐久性对石油的安全开采至关重要，然而固井水泥环开裂所造成的层间封隔失效，将导致井下地层流体窜流，严重威胁固井安全。目前研究仅限于解决小区域裂缝防御及井下裂缝的闭合，因此建立大范围的裂缝防御及高时效自修复体系极具经济意义和研究前景。本项目通过探究大范围能量耗散型裂缝防御结构的诱导，揭示油井水泥微观抗裂机理；基于分子调控制备渗透结晶活化剂，以延迟体系中部分水泥的水化，奠定裂缝渗透结晶自愈的反应基础；通过引入以碳纳米管为主体的海藻酸钠多层仿肌腱结构有机质，揭示自愈产物仿生沉积机理，彻底实现从结构到功能的自修复。该研究将为无需人工干预的自愈固井水泥体系的开发提供理论指导和技术保障，从而实现固井技术的高效智能化发展。

油井的完整性和耐久性对石油的安全开采至关重要，然而固井水泥环开裂所造成的层间封隔失效，将导致井下地层流体窜流，严重威胁固井安全。目前研究仅限于解决小区域裂缝防御及井下裂缝的闭合，因此建立大范围的裂缝防御及高时效自修复体系极具经济意义和研究前景。本项目研究了高分散性纳米尺度增韧剂，解决了纳米颗粒在水泥水化过程中的团聚难题，突破了作用范围限制，提高了其增韧效率；基于分子调控制备渗透结晶活化剂，延迟体系中部分水泥的水化，实现分级水化及后期裂缝的高效修复；构建海藻酸钠多层仿肌腱结构有机质，揭示自愈产物仿生沉积机理，提高自修复区的结构完整性。该研究将为无需人工干预的自愈固井水泥体系的开发提供理论指导和技术保障，从而实现固井技术的高效智能化发展。