Hydrocarbon atmosphere self-healing particles are used for oil well cementing repair after fracturing

With the rapid development of tight and unconventional oil and gas resources, maintaining cement sheath integrity is crucial for ensuring zonal isolation and wellbore safety. Conventional cement systems are prone to cracking under downhole conditions, which compromises their sealing capacity. This study develops novel self-healing particles specifically designed for oil well cement that exhibit excellent thermal stability and expand significantly when exposed to methane. A series of experiments demonstrated that the self-healing mechanism involves two distinct patterns: “single-point expansion” and “spreading adhesion”, which effectively seal cracks under hydrocarbon stimulation. The particles showed good compatibility with cement slurry and common additives, enabling a practical self-healing cement formulation. Field applications in two pilot wells confirmed smooth mixing and trouble-free cementing operations. These findings offer both theoretical insights and technical support for the use of hydrocarbon-responsive self-healing cement systems, thereby enhancing long-term sealing performance in challenging downhole environments.