Development and Application of Low-Temperature Anti-Migration and Accelerating-Type Anionic SBR Latex Cement Slurry
摘要
In order to solve the problems of unstable state, long thickening time and low compressive strength under low-temperature conditions when anionic SBR latex is directly applied in oil well cement slurry, the suitable stabilizers and early strength agent were optimized by a amount of experiments. The styrene-butadiene latex was composed of 75% of styrene butadiene latex puree, 3% of the nonionic surfactant NS-1, 0.8% of nonionic surfactant NS-2, and 6% of the soluble glass as well as the addition of a certain amount of preservatives and deionized water, named as BH-G502. The structures of the samples were characterized by laser particle size analysis, Zeta potential analysis and scan electron microscopy (SEM) techniques. The particle size of BH-G502 solution is 50–150 nm, and the zeta potential is − 25 mV. The mechanical stability, salt and temperature resistance of the latex cement slurry which was mixed into the latex BH-G502 were studied. It was shown that the cement slurry with 4–8% of latex BH-G502 has well performance of stability at temperatures of 40–80 °C, and thickening curve of cement slurry was showed right angle thickening. In addition, the BH-G502 was exhibited excellent half-saturation salt resistance properties. The thickening time curve of the slurry which prepared with half-saturated salt water was smooth and rises steeply at right angles. Adding latex to cement slurry not only reduces the cement slurry fluid loss, but also ensures that the latex cement slurry has good overall performance. The cement slurry exhibited excellent combination properties, such as good rheological properties, low fluid loss, zero free liquid, and the compressive strength of the cement stone was more than 14 MPa after curing for 24 h. The Low-temperature anti-migration and Accelerating-type Anionic SBR Latex cement slurry has been applied for 3 wells with high cementing quality.