一种新型无固相钻井液抗高温增黏剂OA

The Ordovician buried-hill reservoir in Liaohe Oilfield exhibits a challenging high-temperature(200℃at reservoir center)and low-pressure(pressure coefficient 1.01～1.06)environment characteristic of typical high-temperature,low-pressure oil/gas reservoirs.To achieve formation protection,a solids-free water based drilling fluid was prioritized,with tackifier selection being critical.Through molecular structure optimization,a novel high-temperature/salt-resistant tackifier was developed using four monomers:N-vinylpyrrolidone(NVP),2-acrylamido-2-methylpropane sulfonic acid(AMPS),N,N-diethylacrylamide(DEAA),and 1-(3-sulfopropyl)-2-vinylpyridinium hydroxide inner salt.The synthesis employed N,N'-methylene bisacrylamide as crosslinker with potassium persulfate and sodium bisulfite as redox initiators.FTIR and TGA analysis confirmed successful polymerization,demonstrating superior thermal stability with 296.66℃initial decomposition temperature and only 45.96%mass loss during degradation phase,outperforming commercial HE300.The fluid achieved remarkable rheological performance with 722 consistency coefficient(K)at 0.5%concentration.Laboratory evaluations verified exceptional thermal stability up to 220℃and saturated salt tolerance.Field applications demonstrated excellent viscosity-enhancing performance and robust durability of this novel tackifier,providing vital technical support for buried-hill reservoir development and high-temperature formation drilling operations.