RESEARCH AND APPLICATION PROSPECT OF RISERLESS MUD RECOVERY DRILLING TECHNIQUE

Riserless mud recovery(RMR) technology is a top-hole drilling system that uses Subsea Pump Module located at seabed to return fluid and cuttings from hole annulus to drilling ship via Mud Return Line. RMR technology has resolved the problems in deepwater drilling,drilled top-hole of deepwater safely and obtained a wide range of commercial applications at abroad. At present,RMR has been developed from shallow water RMR to deepwater and ultra-deepwater RMR. At the same time,the Controlled Mud Pressure (CMP) system of AGR Co. based on RMR system combined with Subsea BOP and conventional marine riser were used to drill rest section of well besides top-hole. CMP has the advantages of dual gradient drilling and managed pressure drilling. Practice showed that the drilling cost of RMR technique was lower, and the drilling speed of deepwater drilling was faster, it had a large potential market and advantage in exploitation of deepwater oil and gas in China in the future.