Research Status and Development Prospect of Wellbore Integrity in China

Abstract

Summary As the exploration and development of oil and gas move into increasingly challenging locations and harsher environments, well integrity becomes more difficult to maintain. High temperatures, pressures, and corrosion can all contribute to wellbore integrity failure. Such failures can have significant financial and environmental consequences, including gas leakage and fluid spills. In this paper, we review the development and technical advancements of wellbore integrity research both in China and abroad and look forward to the development direction of wellbore integrity in China. We provide basic background knowledge for those interested in wellbore integrity and also share the progress and development direction of integrity research for wellbore integrity researchers. Through research and analysis, some conclusions can be drawn. Countries around the world are actively studying wellbore integrity and have developed a large number of standards, especially the United States and Norway, which have the most standards. The most common way to analyze wellbore integrity is to first divide the entire wellbore into different wellbore barrier units according to different standards, such as ISO 16530-1, and then study risk factors and integrity management measures in different units. Mainstream research is mostly carried out around the integrity of casing, cement, and tubing, and many achievements have been made, but the study of packer and downhole safety valve is still on the way. Wellbore integrity risk assessment aims to quantify potential risks and establish risk levels to support decision-making for on-site wellbore integrity control. This is achieved by identifying factors affecting wellbore integrity, establishing an evaluation index system and processing evaluation indicators to determine failure probability and impact consequences. The resulting risk value can be divided into different areas using the “as low as reasonably practicable principle” or a risk matrix graph. However, due to the complexity of the factors involved and the subjectivity of risk classification rules, there are still challenges in promoting the evaluation model and reducing errors in the evaluation results. China should actively promote interdisciplinary integration and respond to the call for “dual carbon goals” to break through the current bottleneck in wellbore integrity research. This can be achieved by promoting the development of quantitative wellbore integrity risk assessment methods, developing supporting evaluation software based on big data, and by tackling the integrity challenges faced by different types of wells and promoting the development of wellbore integrity discipline.