Pratama Muhammad Andiva, Mahmoud Ahmed Abdulhamid, Elkatatny Salaheldin
College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
ACS Omega. 2023 Feb 21;8(9):8773-8778. doi: 10.1021/acsomega.2c08253. eCollection 2023 Mar 7.
Casing cementing is one of the most crucial operations in the oil well drilling process since it determines the durability and stability of the well throughout its life. Different additives have been mixed into the oil well cement slurry to improve the properties of both the cement slurry and the solidified cement sheath. Graphite is a waste material with a huge potential to be utilized in cementing to improve the properties of the oil well cement and reduce the graphite waste content in the environment. This study intends to analyze the effect of graphite on alteration in properties of the cement compressive and tensile strength, Poisson's ratio, Young's modulus, porosity, and permeability for three days of curing. Based on the trend of the properties during the three days of curing, equations were established to describe the future change in cement properties with time. Two formulas of cement, the base (with no graphite) and graphite-based (with 0.2% by weight of cement graphite) were prepared in this study. The results showed that the graphite successfully increased the compressive strength, tensile strength, and Poisson's ratio of the cement sheath, throughout the curing process. Young's modulus was decreased after the incorporation of graphite which indicates an enhancement in cement resistance to shear forces. The porosity and permeability were also decreased indicating formation of a more densified cement sheath.
套管固井是油井钻井过程中最关键的作业之一，因为它决定了油井在其整个生命周期内的耐久性和稳定性。不同的添加剂已被混入油井水泥浆中，以改善水泥浆和固化水泥环的性能。石墨是一种具有巨大利用潜力的废料，可用于固井，以改善油井水泥的性能，并减少环境中的石墨废料含量。本研究旨在分析石墨对养护三天的水泥抗压强度、抗拉强度、泊松比、杨氏模量、孔隙率和渗透率性能变化的影响。根据养护三天期间性能的变化趋势，建立了描述水泥性能随时间未来变化的方程。本研究制备了两种水泥配方，即基础配方（无石墨）和石墨基配方（水泥重量的0.2%石墨）。结果表明，在整个养护过程中，石墨成功提高了水泥环的抗压强度、抗拉强度和泊松比。加入石墨后，杨氏模量降低，这表明水泥对剪切力的抵抗力增强。孔隙率和渗透率也降低，表明形成了更致密的水泥环。
