An analytical solution to simulate the effect of cement/formation stiffness on well integrity evaluation in carbon sequestration projects

Abstract

Cement Sheath integrity has been gain more attention due to the increase of carbon sequestration activities in the recent years. Sealing ability of cement sheath can be lost because mechanical disruption in the CO 2 injection wells. Cement sheath mechanical failure can occur in the CO 2 injection wells. This paper proposes an analytical solution to address this issue. Cement sheath and formation rock stiffness are considered in the proposed model to simulate the cement sheath sealing ability on different depth of the formation. Both mechanical properties of cement and formations are evaluated and analyzed. Real field example is also provided. Young's modulus of cement sheath is identified as a major factor that affects the sealing ability of cement sheath. The sealing ability of cement sheath in shale formation is better than that in sandstone formation. Weak cement has better sealing ability than strong cement. The critical failure point lies at the top of sandstone formation. This model can also be used to design and optimize the cement system of new CO 2 injection wells in carbon sequestration projects.

Improving Phenology Representation of Deciduous Forests in the Community Land Model: Evaluation and Modification Using Long‐Term Observations in China

“…Experiments under a controlled environment indicated that additional chill accumulation before leaf unfolding dates may decrease the heat requirement (Couvillon and Erez, 1985; H. Wang et al., 2020). Therefore, the involvement of such a negative relationship between heat requirement and chill accumulation was regarded to be more reasonable and can improve model performance in simulating leaf unfolding dates (Chuine et al., 1999; Darbyshire et al., 2016; Y. H. Fu, Piao, et al., 2014; Y. H. Fu et al., 2015; B. Li et al., 2015). The alternating CU1 model remains a large deviation in some subtropical forests, possibly because those species have a small chilling requirement, which would lead to an earlier leaf unfolding date and might be at greater risk from early frost damage (Murray et al., 1989).…”

“…The phenological model is a feasible and effective method for assessing relationships between phenology and climate and predicting phenological changes under varied climatic and anthropogenic scenarios (B. Li et al., 2015; Zhao et al., 2013). Underlying mechanistic processes governing phenological events are empirically represented via statistical relationships in the phenological model (Piao et al., 2019).…”

Analytical Perspectives on Cement Sheath Integrity: A Comprehensive Review of Theoretical Research

“…Li et al 71 investigated the influence of cement sheath and formation stiffness on cement sheath sealing capacity based on anisotropic stress. The cement sheath/formation stiffness ratio was used to describe the impact of formation stiffness on cement sheath sealing.…”

Suggestions on the Development of Environmental Monitoring Technology of CO2 Geological Storage and Leakage under the Background of China’s “Double-Carbon” Strategy

“…In the process of CO 2 geological storage, with the passage of time, on the one hand, the weak acid produced by CO 2 dissolution corrodes the casing and annulus. On the other hand, the temperature and pressure conditions change due to CO 2 injection, which makes the casing or cement sheath plastically deform and destroys the integrity of the wellbore [28,29].…”