Abstract:
In order to meet the technical requirements of acid fracturing with long fractures and deep penetration in the Tuoputai Block of the Tahe Oilfield,a high temperature resistant and salt tolerant acid thickener TP-17 was developed to accommodate the high temperature geologic characteristics of Ordovician Formation.With crylamide (AM) as the principle component,the high temperature resistant and salt tolerant monomer 2-methyl-2-acrylamido-sulfonic acid (AMPS) and self-made cationic monomer (X) and maleic anhydrides (MA) as auxiliary components,the quadripolymer TP-17 formed by polymerization.Research results showed that optimal conditions of polymerization was in terms of molar ratios of 5:3:2,i.e.three monomers AM,AMPS and X,which have total mass fraction of 30.0%,with MA mass fraction of 15.0% and initiator mass fraction of 0.4%.The reaction temperature was at 80℃,with concentration of the chelating agent EDTA was 200 mg/L,the reaction time lasted for nine hours,the pH of reaction system was 7.Lab and field test results indicated that TP-17 was an acid thicker with outstanding heat-resistant,salt-resistant,anti-shearing,acid dissolution and compatibility performances.Desirable effects have been observed in acid-fracturing operations of deep carbonate reservoirs.It is considered that the TP-17 is suitable for acid fracturing in fracture-vuggy deep reservoir,with bright prospects of applications.