North Qijia Water Injection For Experimental Study Of Water Quality Limits And Control Measures Of Core Flooding

North Qijia oilfield consists of125water injection wells, open wells68, closes in57wells, in which no water off in53wells, water injection can not meet the demand problemwith injection. In order to solve North Qijia oilfield injection water problems, to carry outwater quality analysis laboratory, core divided into routine analysis experiment, coreflooding experiment, analysis of clay mineral composition, anti-swelling agent screening,prevention and screening scale of chelating agent, deep guide thinning agent selection,chelating agent, stabilizing agent, hydrophobic agent compatibility experiment guide.Factors affecting find alignment north oil field, and gives the North Qijia injection waterquality limits, such as the content of suspended solids, median diameter of suspendedparticle, mineralization degree, determine the actual injection capacity in North Qijiaoilfield, the ground processing technology were improved, there is targeted to takepreventive measures, to explore a new method of low cost increase injection, in order toachieve the improvement of North Qijia oilfield waterflooding. Purpose. Through thestudy to obtain the following understanding:One is to determine the reservoir damage North Qijia oilfield through the analysis:the shale content is higher in the reservoir rock mineral composition, material base of theexistence of formation damage, mainly for the particle migration (sensitivity), acidsensitivity and water sensitivity; injection water quality unqualified; poor compatibilitybetween injected water and formation water, can produce fouling deposits; the salinity ofinjected water is low, easy to cause the expansion of clay minerals in the reservoir,reservoir pore blockage.Two is given by core analysis of reservoir sensitivity evaluation: the reservoir rockshowed weak speed sensitivity or moderate to weak speed sensitivity, between criticalvelocity is between3ml/min～4ml/min; weak sensitivity to medium to weak watersensitive reservoir is. Critical salinity is8000mg/L～10000mg/L; acid sensitivity of thereservoir rock is more serious; alkali sensitivity and alkali sensitivity reservoir is themiddle class.The three was determined by the experiment of injected water additives, includingformulation of chelating agent, stabilizing agent, deep guide hydrophobic agent, reservoirpore protective agent. The four is to experimentally determine the injection water quality limits, boundaries,including suspension injection limit ion content in water...