耐高温海水基压裂液用聚合物研制及性能研究OA

To meet the requirements for hydraulic fracturing of deep and ultra-deep offshore oil and gas wells while ensuring the thermal stability and proppant-carrying capacity of fracturing fluids,a high-temperature and high-salinity hydrophobic associative polymer,TH-200,was synthesized using acrylamide,acrylic acid,2-acrylamido-2-methylpropanesulfonic acid,and the hydrophobic monomer DM.The structure of polymer TH-200 was characterized by infrared spectroscopy,proton nuclear magnetic resonance spectroscopy,and thermogravimetric analysis,and its main performance as a fracturing fluid thickener was further evaluated.The results show that polymer TH-200 is a quaternary copolymer with excellent thermal stability.It exhibits a viscosity increase rate of 92%in seawater,indicating good viscosity enhancement and salt resistance,and is therefore suitable for high-mineralization environments such as seawater.The critical intermolecular association mass fraction is approximately 0.25%.Molecular dynamics simulations revel that as the AMPS monomer concentration increases,the gyration radius of polymer segments significantly improves,with minimal influence from temperature and mineralization.0.1%polymer solution prepared in seawater achieves a drag reduction rate of up to 78%.The seawater-based fracturing fluid formulated with 1.0%polymer TH-200,0.5%chelating regulator,and 1.0%organic zirconium cross linking agent maintains a viscosity of 110 mPa·s after shearing at 200 ℃ and 100 s−1 for 90 minutes.These results demonstrate favorable delayed cross linking performance,excellent thermal and shear resistance and outstanding proppant-carrying capabilities,meeting the demands for fracturing operations in offshore reservoirs at200 ℃.