Monitoring Technology of Formation Pressure While Drilling Under High Temperature and High Pressure Based on Gas Logging
Based on the basic principle of gas logging pressure monitoring,the calculation methods of static equiva-lent mud density(ESD)and circulating equivalent mud density(ECD)of drilling fluid under high temperature and high pressure formation are presented.On this basis,monitoring,while drilling,on formation pressure of well under high temperature and high pressure is carried out.It is found that when the bottom-hole pressure difference increases,the gas measurement decreases exponentially,and when the bottom-hole pressure is over-balanced,the gas measurement will not decrease to 0,but maintain a low level.Based on this analysis,the correlation between circulating gas and circulating pressure difference as well as single gas and static pressure difference is established,and the correlation equation between bottom hole pressure difference and gas measurement value is established to e-valuate the formation pressure qualitatively and quantitatively.
gas loggingformation pressuremonitoring while drillinghigh temperature and pressure
国家科技期刊平台
NSTL
万方数据
维普
