MATCHING TECHNOLOGIES OF MUD LOGGING UNDER GAS DRILLING

Compared with plenty of traditional drilling technologies,gas drilling has obvious advantages in increasing drilling speed,protecting and discovering reservoir.But,this drilling suffers some problems while mud logging,including difficultly forecasting engineering abnormity,identifying cuttings,and determining oil,gas and water layers.In this study,some matching technologies of mud logging under gas drilling are developed,for example,to establish the model to forecast abnormality,to develop the safety-monitoring system,to research the lagged-time calculation software,and to form some evaluation methods for both elemental mud-logging lithological interpretation and gas logging interpretation.These technologies have been applied to many wells in northeastern Sichuan Basin.And their application shows that they can ensure drilling safety,raise oil and gas discovery ratio,and enhance mud-logging quality.