Development And Mechanism Analysis Of High Temperature Viscosifier For Deep Buried Hill Reservoir Drilling Fluid

At present, deep reservoir drilling completion fluid cannot meet the needs of hightemperature deep buried hill reservoir drilling engineering and reservoir protectiontechnology, due to its poor anti-temperature capability. The text used high temperatureresistance polymer viscosifier in the clay-free and solid-free drilling fluid as technologicalbreakthrough point. Based on basic theoretical research for high temperature resistancepolymer viscosifier, novel temperature polymer viscosifier, high temperature buried hillreservoir water-based drilling completion fluid system which had a temperature resistancecapacity of more than180℃were eventually developed.On the basis of basic theoretical research to improve the temperature resistance ofpolymer and the optimization design of polymer molecular structure, novel temperatureresistance polymer viscosifier (SDKP) was developed though synthetic optimizationexperiment method. The SDKP was characterized with FT-IR,1H-NMR and UV spectra.Elementary analysis was used in determining polymer composition. GPC measurement wasused to show the weight average molecular weight. Performance evaluation results show thatcompared with similar foreign most representative product（HE300）, SDKP has betterviscosifying, temperature resistance and salt resistance performance, which layed thefoundation for building the high temperature buried hill reservoir drilling completion fluidsystem.Mechanism of novel temperature resistance polymer viscosifier (SDKP) was conducted.ESEM was applied to observe the micro-morphology of viscosifier brine solution. Themechanism of viscosifying and salt tolerance at room temperature was analysed.Hydrophobic polymer molecular chain was analysed though the test of variable temperature 1H-NMR, variable temperature visible spectrophotometer and DSC. Associating viscosifyingmechanism at high temperature was analysed though the high temperature flow test ofpolymer solution and hydrophobic polymer molecular chain. The mechanism oftemperature-resistant mechanism for SDKP was discussed though FT-IR,1H-NMR andElementary analysis of SDKP after high temperature aging.According to the characteristics of the deep ordovician buried hill reservoir, theordovician buried hill reservoir damage mechanism was analysed based on the buried hillreservoir characteristics, sensitivity, water damage analysis. And reservoir protectiontechnical counter measures was proposed. Using novel temperature resistance polymerviscosifier (SDKP) as the key additive, the formulation of high temperature clay-freewater-based drilling fluid (its temperature resistance capacity was up to180℃) and two setsof low clay water-based drilling fluid system (the temperature resistance capacity for1%ofbentonite content of system was up to200℃, the temperature resistance capacity for3%ofbentonite content of system was up to230℃) was developed. The three sets of drilling fluidsystem have good reservoir protection performance, strong ability of carrying rock, saltresistance, inferior soil pollution and inhibition.Finally, the industrial production pilotscale experiment of novel temperature polymerviscosifier were conducted successfully, and have achieved better field application test inMG-H117branch horizontal well section of Liaohe Xinggu buried hill.