Research And Application Of Reservoir Protection Technology In Nanpu District 1-1 Block 29

This paper aims at reservoir damage problem of Nanpu District 1-1 Block 29, and carries out a system research of reservoir protection technique and analyses the reservoir characteristics distribution regularity and particularity in Segment East 1 Group Guantao of Nanpu District 1-1 Block 29. Group Guantao is weak- medium velocity sensitivity, weak-medium weak water sensitivity, moderate salt sensitivity, and the critical salinity is 3359-6719 mg/l, medium weak – strong alkali sensitivity, and the critical pH is 7-8.5, medium weak- very strong acid sensitivity. Segment East 1 has no velocity sensitivity, medium- weak water sensitivity, moderate salt sensitivity, and the critical salinity is 3795 mg/l; medium- weak alkali sensitivity and the critical pH is 10.5, and no acid sensitivity.In view of the defects of traditional plugging materials, optimize the JRYBC-2 ultra-low permeability film plugging material and JRYBC-2 can form a dense sealing membrane on the wall rock, thus form protection layer in the periphery of the borehole wall. JRYBC-2 has a little effects on drilling fluid rheological property, has strong plugging ability and obvious effects of sand bed filtration reduction. With 40~60 mesh quartz sand bed the instantaneous saturated depth is 5.5cm, and 6cm in 0.7 MPa after 5min. On this basis by screening agents, determine the KCL film seal low invasive drilling fluid formula: 3%~5% sodium soil slurry + 0.3%~0.6% KPAM + 1.5% ~ 2% SMP-1 + + 1.5%~2% SPNH + 2% low fluorescence sulfonated asphalt + 2% polymeric alcohol +3%~5% KCL + 2%~3% ultra-low permeability film plugging agent + limestone or barite. With this formula the core permeability recovery value for low, medium and high permeability reservoir is over 90% and dynamic filtration is below 8 ml indicating it has good formation protection effect.KCL film plugging low invasion drilling fluid has been applied in Nanpu District 1-1 Block 29, the skin factor of testing for oil was negative, and production wells achieved more than 95% without acidification directly put into production, BOPD was average 25.7t in early operation higher than the design capacity which demonstrating the drilling fluid formula effectively assurance the reservoir protection effect.