Research and Application of Underwater Anti-dispersion Anti-channeling Cement Slurry Technology

In order to solve the problem that conventional cement slurry in high water-cut is easily eroded and diluted by formation water, resulting in cement dissolution in the water layer, reducing the quality of interfacial cementation and destroying the sealing integrity of cement ring. Based on the electric neutralization, electric double layer compression and colloidal stabilization theory, the underwater anti-dispersion agent was developed to form underwater anti-dispersion anti-channeling cement slurry technology. The cement slurry system can form reversible flocculation structure and maintains the dynamic balance of “flocculation–dissociation”. Furthermore, the system does not separate and disperse in water, and has significant water erosion resistance, allowing it to avoid the “dissolution migration” and “mass exchange” by formation fluid after cementing, to improve the quality of interface cementation. In this paper, the evaluation method of water channeling for cement slurry is constructed. With this method, the underwater anti-dispersion anti-channeling cement slurry and the conventional cement slurry were evaluated comprehensively, indicating that the underwater anti-dispersion anti-channeling cement slurry has an outstanding resistance to water invasion and water channeling. It provides a new technique for cementing and water plugging of wells with high water cut.