Drilling Technology for Highly Efficient Development of Low Permeability Oil Gas Fields

To develop low permeability oil gas fields efficiently and reach maximum economic profit,drilling technology suitable for these kinds of fields has been studied.By mechanism analysis,lab and field tests,drilling techniques improving drainage area,reservoir drilling rate,drilling efficiency,and reservoir protection and key completion techniques for low permeability reservoirs have been systematically studied.Drilling techniques improving drainage area include five-stage branch wells,radial drilling,fishbone-like horizontal wells,rotary steerable drilling; techniques improving drilling efficiency consist of air drilling,underbalanced drilling and bit design optimization; low permeability sand reservoir protection techniques concentrate around water blocking resistant clay free drilling fluid,new biologic completion fluid and degradable organic salt drilling and completion fluid; completion techniques for low permeability reservoirs include horizontal well stage completion and techniques improving cementation quality.High temperature and pressure resistant wireless MWD,electromagnetic wave measurement device suitable for foam drilling,the near bit deviation and azimuth angle gamma measuring device suitable for thin inter-bed oil gas reservoirs and downhole micro-flow measurement device have been developed.These techniques have obtained good results but there are still some issues needing to be resolved,which is the direction of future research.