Synthesis and Performance Evaluation of a Novel Heat and Salt-Resistant Gel Plugging Agent

Tahe oil field is a typical fissure cave carbonate reservoir with a temperature of up to 120 similar to 140 degrees C and a total salinity of formation water of (20 similar to 25) x 10(4) mg/L. In this paper, AM/AMPS was selected as the polymer, 1, 5-dihydroxy naphthol as the cross-linking agent, and polypropylene fiber as the system stabilizer to synthesize a novel gel plugging agent independently; the gel has good thermal stability at a high temperature of 130 degrees C and increased salinity of 20 x 10(4) mg/L, and has a dense and relatively stable three-dimensional network structure under a scanning electron microscope. The performance evaluation of the gel plugging agent indicated that: the gel dehydration rate increased gradually with the increase in temperature and salinity, making it suitable for reservoirs with temperatures below 140 degrees C and formation water salinity below 250,000 mg/L; the viscosity of the gel bulk was 125.3 mPa.s, the post-gelatinizing viscosity was 42,800 mPa.s, and the gelatinizing time at 120 degrees C, 130 degrees C and 140 degrees C was 10-20 h, 8-18 h, and 7-16 h, respectively.

Automated summary

This study successfully synthesized a gel plugging agent with good thermal stability and high salinity adaptability, suitable for reservoirs with high temperatures and high salinity such as the Tahe oil field.