Synthesis And Application Of Filtrate Reducers And Retardants With Resistance To High Temperature And Salt For Drilling Fluid

Much higher requirements of drilling fluids are needed for deep drilling process,and oil-based drilling fluids are widely utilized for the sound stability,inhibition,and filtration properties under high temperature conditions.The application of oil-based drilling fluids is limited for costing consideration.In deep drilling,the rheological property control becomes much more important for water-based drilling fluids than that of the oil-based drilling fluids,and the fluid loss must be strictly controlled.The properties of drilling fluids become much more flexible in the complex deep formations,especially under high temperature and high salinity conditions.For the safety and fast drilling of high temperature and deep wells,drilling fluids with ultra high temperature resistant properties are needed to meet the engineering requirements.Drilling fluid addictives should enhance hydration properties of clay particles.The research on the mechanisms of addictives would help molecule structure design for filtrate reducers and polymers.In this paper,the influences of high temperatures on clay particles,addictive properties,and drilling fluid properties,especially on rheological properties and loss rates are analyzed,and the mechanisms of drilling fluid property control are discussed,and principle explanations of high temperature drilling fluid control of this type are also made.Appropriate polymer filtrate reducers,terpolymer inhibition addictives and the compound method are selected for synthons,and experimental comparisons are made with other drilling fluids.Further researches are made on the recipes.In calcium salt based drilling fluid,AV increased form 5 mPa·s to 18 mPa·s before aging,while it increased from 10 mPa·s to 40 mPa·s after aging.In composite base solutions,AV decreased form 40 mPa·s to 18 mPa·s before aging,while it decreased from 18 mPa·s to 11 mPa·s after aging.The rolling of the argillaceous shale recovery rate with the increase of addition.Under 105?,the recovery rate exceeds 90.0% with 0.3% addition,while that is as high as 97.88% with 2.0% addition.Under 220 of hot rolling,the recovery rate is 86.87% with 2.0% additio? n.The drilling fluids are applied in Well A,B and C based on common drilling fluids of the oilfield and laboratory experiments,focusing on the performance of fluid loss resistant and inhibition addictives in the drilling process.Performance of temperature and salt resistant drilling fluids: sulphonate water-based drilling fluids are together used in extreme conditions;the fluids can produce good loss resistance and inhibition,stability under high temperatures,building capacity and stability,good rheological property in deep well intervals,and low overall viscosity and shear.Laboratory experiments provide good technical support and assurance for field experimentation.The products are expected to be widely used in water-based drilling fluids after some later improvements.