Abstract
Managed Pressure Drilling (MPD) has been widely considered as the best alternative for many drilling-related problems such as stuck pipe, lost circulation, excessive mud cost and narrow operating windows in deepwater environments. Looking for these benefits, many oil rigs has been rigged up with the MPD system, mainly because drilling engineering is emerging to even more challenging environments with the depletion of the current oil reserves. An example of that is the recent exploration of the Brazilian pre-salt fields in Santos Basin located 200km away from coast, in over 2100m water depth and up to 7000m below sea level.
Composed by huge carbonate reservoirs, the challenge to drill this porous formation has overcame the challenge to drill the two thousands meters of salt. Due to the heterogeneity of this type of formation, vugs and natural fractures are often encountered, resulting in severe or total losses experiences. Pressurized Mud Cap Drilling (PMCD) is one of MPD variations applied in situations when high rate of lost circulation occurs and can also been described as the non-return drilling method. This paper addresses a discussion regarding well control issues, application, fluid selection and safety considerations using PMCD and also the difference on the equipment alignment among this technique and others MPD methods.
