Characteristic of AMPS-Based Self-Healing Material and the Effect on the Properties of Oil Well Cement Slurry

The self-healing cement used in oil wells aims to provide long-term interlayer isolation by enabling the cement system to repair itself. This paper compared the absorption properties of 2-acrylamido-2-methyl propanesulfonic acid (AMPS)-based superabsorbent polymer (SAP) and acrylic acid (AA)-based SAP in water and cement slurry filtrate. The effect of cement slurry filtrate on the water absorption properties of the two SAPs was evaluated. The results showed that the calcium ions in the cement slurry would crosslink with the carboxyl groups in the AA-SAP, increasing the crosslink density and greatly reducing its absorption rate in water. Compared to AA-SAP, AMPS-SAP is more suitable for oil well cement slurries. AMPS-SAP can help reduce the fluid loss of cement slurry. The addition of 0.4% AMPS-SAP in cement slurry results in a 64 mL decrease in fluid loss. The properties (rheological properties, thickening time, and compressive strength) of cement slurry meet the requirements for well cementing construction.