STUDY AND APPLICATION OF NEWLY ORGANIC CATIONIC GEL DRILLING FLUID

According to the complex formation complexion of stratum of ZPEB (multi-fault,high temperature,condensing salt),a novel drilling fluid additives-organic positive gel (WPS) is developed through many tests.Results in laboratory showed that organic positive gel (WPS) has good effects in temperature-resisting,salt-resisting,collapse-preventing,lubrication properties and formation protection.The novel drilling fluid system of organic positive gel can be applied in saturation salt solution,stable at 150℃ and the value of durchgriff reversion was more than 80%.The new system was applied as field experiment in 20 wells such as liu (side tracking) 20-2,wen 72-169 and bai 46 etc.In-situ application indicated that the new system had strong dilution shearing property,good cutting carrying capacity,strong inhibition property to shale and strong reservoir protecting ability.