Drilling process optimisation utilizing MWD transmitted downhold drilling data

摘要

MWD technology (Measurement While Drilling) is applied to transmit directional and petrophysical data while drilling. It is enabling technology to drill complex directional well profiles. However, while using downhole data for directional control, the drilling process is still controlled mainly on the basis of traditional surface acquired data such as rotary speed, hook load, rate of penetration etc. The transmission and utilization of downhold drilling process data offer a not yet fully explored potential for drilling process optimization. Modern sensor technology close to the bit can provide not only more accurate data, but also important additional parameter not available at the surface. Examples for value-adding downhole drilling process data are annulus pressure, weight-on-bit, drillstring bending, bit torque, downhole rotary speed and vibration measurements. The simultaneous evalution of downhole and surface data can provide additional drilling process information on drilling hydraulics or drillstring mechanics in the wellbore. The article describes the drilling process data available downhole, provides numberous application examples and concludes with an outlook on future developments in drilling process optimization utilizing realtime downhole data.