弱凝胶化热敏颗粒封堵剂的制备及性能评价OA

To address the technical problems of poor retention ability,low plugging strength,and easy water dilution of plugging agents in large-vug plugging for fractured-cavity reservoirs in the Tahe Oilfield,a terpolymer gel AAD was synthesized using acrylamide(AM),2-acrylamido-2-methylpropanesulfonic acid(AMPS),and diallyldimethylammonium chloride(DMDAAC)as monomers.A composite system of weakly gelatinized thermosensitive particle plugging agent was constructed,and its temperature resistance,salt tolerance,water dilution resistance,compressive strength,and plugging performance were systematically evaluated.The results show that the composite system exhibits excellent temperature resistance,salt tolerance,and water dilution resistance.The optimized formula is adding 0.2%(w)polymer AAD in 8%(w)bentonite+15%(w)S95 slag powder+2%(w)cement+75%(w)simulated formation water system.This system can maintain favorable viscosity and stability at 130℃and 20×104 mg/L salinity,with an adjustable curing time of 1-5 h.The compressive strength after curing reaches 3.3 MPa,and the system shows excellent plugging effect on large vugs and fractures with a breakthrough pressure higher than 2.23 MPa.This study can provide technical support for deep plugging in fractured-cavity reservoirs.