BRIGE: Characterizing the Rheological and Microstructural Evolution of Oil Well Cement Slurries under Elevated Temperature and Pressure Conditions

BRIGE：表征高温和压力条件下油井水泥浆的流变和微观结构演变

• 批准号: 1342377
• 负责人: Shiho Kawashima
• 金额: $ 17.18万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1342377&HistoricalAwards=false
• 关键词: BRIGE; Characterizing; Rheological; Microstructural; Evolution

Background:Insufficient zonal isolation, or sealing, is a prevalent issue in oil wells, from which many safety, economic, and environmental concerns can arise. And the origin of failure can be traced back to the placement of the fresh oil well cement slurry. During a critical period called transition time, the slurry is static and evolving from a near-Newtonian fluid to a viscoelastic solid due to the progression of cement hydration. If it does not either rapidly develop sufficient static gel strength or set, gas from adjacent geological formations will penetrate the material. This makes the slurry extremely susceptible to gas migration, which can result in permanent fluid channels in the well and compromise the sealing performance of the eventual cement sheath structure. Technical Description:The objective of the proposed work is to characterize the rheological properties of oil well cement slurries considered to be critical in achieving proper zonal isolation, namely gelation. This will entail measuring the dynamic flow properties under large and rapid deformation and the linear viscoelastic properties at rest. All rheological tests will be performed with rigorous attention to the effects of elevated temperatures and pressures to simulate down-hole conditions, and shear history to simulate different pumping conditions. The approach will be to implement complementary shear and extensional rheological techniques that place the sample under dynamic and quasi-static loading to monitor the evolution of rate of gelation and magnitude of static gel strength over the simulated cementing period. And an important complement to the rheology will be to monitor changes in the crystalline phases and pore network of the material, which will help provide insight into flow behavior and sealing performance. This will be done through synchrotron x-ray diffraction and x-ray tomographic microscopy for real-time, in-situ microstructural characterization. Broader Signficance and Importance:As a complex fluid that is continuously evolving, the thermomechanics and time- and shear-dependent flow behavior of fresh cement-based materials presents a challenging characterization problem. And the specific area of oil well cementing is a particularly good example of an application where understanding the fresh-state and early-age properties under severe conditions is critical. The proposed activities will improve understanding of the performance of oil well cement slurries during placement, which can help in the development of effective mix design methodologies and models. Ultimately, this can improve zonal isolation to increase production and safety, and reduce the negative environmental impact of oil well operations. Further, the experimental methodology proposed and developed in the study can potentially be extended to all types of cement-based systems for a wide array of applications. Broadening Participation of Underrepresented Groups in Engineering:An important component of the proposed work is the broadening participation plan, which will focus on supporting women in engineering through direct involvement in research activities at the pre-college, undergraduate, and graduate level. By engaging female students in the proposed research, the PI will present them with the opportunity to impact the field and subsequently give them the confidence and desire to pursue academia or advanced industry careers in engineering and science. And through various outreach programs coordinated by the Office of Outreach Programs and local chapter of Society of Women Engineers at Columbia University, the PI will participate as a guest speaker to present the proposed work and run hands-on lab demonstrations on rheology. This will serve as a means to convey the interdisciplinary nature of her field, invoke interest and recruit students. Further, the PI will encourage her own students to participate in outreach programs so that they, themselves, can go on to serve as role models. As a product of such programs herself, the PI firmly believes that such trickle down approaches are effective.This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.

背景：层间隔离或密封不足是油井中普遍存在的问题，由此引发了许多安全、经济和环境问题。破坏的原因可以追溯到新鲜油井水泥浆的放置。在一个称为过渡时间的关键时期，由于水泥水化的进展，水泥浆是静态的，并且从近牛顿流体演变为粘弹性固体。如果它不能迅速发展出足够的静态凝胶强度或凝固，邻近地质构造的气体就会渗透到材料中。这使得泥浆极易受到气体运移的影响，这可能导致井中永久的流体通道，并影响最终水泥环结构的密封性能。技术描述：所提议的工作的目的是表征油井水泥浆的流变特性，这些特性被认为是实现适当的层间隔离（即凝胶化）的关键。这将需要测量大而快速变形下的动态流动特性和静止时的线性粘弹性特性。所有流变测试都将严格关注高温和高压的影响，以模拟井下条件，以及模拟不同泵送条件的剪切历史。该方法将采用互补的剪切和拉伸流变学技术，将样品置于动态和准静态载荷下，以监测模拟固井期间凝胶速率和静态凝胶强度的变化。流变学的一个重要补充将是监测材料的结晶相和孔隙网络的变化，这将有助于深入了解流动行为和密封性能。这将通过同步加速器x射线衍射和x射线层析显微镜进行实时、原位微结构表征。更广泛的意义和重要性：作为一种不断演变的复杂流体，新水泥基材料的热力学和随时间和剪切的流动行为是一个具有挑战性的表征问题。油井固井的特定区域是一个很好的应用实例，在该应用中，了解恶劣条件下的新鲜状态和早期性质至关重要。拟议的活动将提高对油井水泥浆在投放过程中的性能的理解，这有助于开发有效的混合设计方法和模型。最终，这可以改善层间隔离，提高产量和安全性，并减少油井作业对环境的负面影响。此外，在研究中提出和发展的实验方法可以潜在地扩展到所有类型的水泥基系统，用于广泛的应用。扩大工程领域代表性不足群体的参与：拟议工作的一个重要组成部分是扩大参与计划，该计划将侧重于通过直接参与大学预科、本科和研究生阶段的研究活动来支持工程领域的女性。通过让女学生参与拟议的研究，PI将为她们提供影响该领域的机会，并随后赋予她们在工程和科学领域追求学术界或高级行业职业的信心和愿望。通过外联项目办公室和哥伦比亚大学女工程师协会当地分会协调的各种外联项目，PI将作为客座演讲者参与介绍拟议的工作，并在流变学方面进行动手实验室演示。这将作为一种手段来传达她的领域的跨学科性质，唤起兴趣和招收学生。此外，PI将鼓励她自己的学生参加外展项目，这样他们自己就可以继续作为榜样。作为此类项目的产物，PI坚信这种涓滴式方法是有效的。这项研究是由工程教育和中心部的工程项目扩大参与计划的一部分，即工程项目扩大参与研究启动基金资助的。