A multi-scale approach to characterize and analyze the effect of temperature and pressure on the life well integrity of oil well cements

油气生产在北美能源资源中扮演着重要的角色，这一点可以从油气钻井数量上看出来，在过去的10年里，油气钻井数量一直在显著增加。井固井是井的一个关键方面，原因有三：(1)在井筒内的各种含水、气和含油地层之间提供水力隔离；(2)为套管提供足够的支撑（如防开裂、防屈曲等）；(3)提供外套管防腐保护。井水泥可以采用复杂的混合设计，以承受温度和压力方面的恶劣条件。在高温高压下，井眼水泥的物理和化学行为发生了显著变化。此外，温度和压力会影响控制开裂风险的机械性能（例如粘度和韧性）。不幸的是，在公开文献中，关于温度和压力对油井水泥行为影响的数据非常有限。通过汇集国际专家，拟议的研究项目将采用基于多尺度技术的创新和综合方法来实现以下目标：**(1)表征温度和压力对井固井行为的影响；**(2)为了更好地了解温度和压力对加拿大使用的井固井耐久性的影响；**(3)建立评价井水泥浆环长期耐久性的工程模型；**(4)建立一种新的测试方法，用于自动表征水泥浆体微观结构的机械和化学特性。**通过提高目前对油井水泥的认识，该项目将：(i)推进目前的油井水泥护套做法；（ii）减少水污染的风险；（iii）改善加拿大环境和资源的保护。******

The oil and gas production plays a major role in the North American energy resources as shown by the number of hydrocarbon boreholes which has been increasing impressively in the last 10 years. Well cements is a critical aspect of a well for 3 reasons: (1) provide hydraulic isolation between various water, gas, and oil bearing formations within the wellbore; (2) provide adequate support for the casing (e.g., cracking, buckling prevention, etc.); (3) provide external casing corrosion protection. Well cements can have complex mix designs to withstand severe conditions in term of temperature and pressure. The physical and chemical behaviour of well cements changes significantly at high temperature and pressure. Furthermore, temperature and pressure affect the mechanical properties (e.g., viscosity and toughness) which govern the risk of cracking. Unfortunately, the data available in open literature on the effect of temperature and pressure on the behaviour of oil well cements is quite limited. By bringing together international experts, the proposed research project will employ an innovative and comprehensive approach based on multi-scale techniques to achieve the following objectives: **(1) To characterize the effect of temperature and pressure on the behaviour of well cements; **(2) To better understand the effect of temperatures and pressures on the durability of well cements employed in Canada;**(3) To develop an engineering model for assessing the long term durability of well cement sheaths; **(4) To set-up a new test methodology for automatically characterizing mechanical and chemical properties of the microstructure of a cement paste. **By improving the current knowledge on oil well cements, the project will: (i) advance the current practise for well cement sheaths; (ii) reduce the risk of water contamination; (iii) improve the preservation of the Canadian environment and resources.******