Petroleum Engineering, China University of Petroleum（EAST CHINA）
This paper analyzed the characteristics of managed pressure drilling (MPD) technology and impact of wellhead back pressure on the wellbore annulus pressure profile, and found that the application of this technology provides room for improvement to the current casing program design. Meanwhile, the equivalent density of drilling fluid in wellbore annulus needs to consider the impact of back pressure. On this basis, established methods of casing program design for top-down design approach and multi-pressure system formation in MPD. Though comparing and analyzing the results of casing program design in MPD and conventional drilling, it can be concluded that: for the top-down design method, each layer of casing can reach a deeper depth, even can reduce the casing level; for the multi-pressure system formation, using wellhead back pressure to make the wellbore annulus pressure profiles bend, so that it can cleverly pass through the complex formation which needs multi-layer intermediate casings in conventional drilling, and then the well structure can be simplified.