BOREHOLE CLEANING TECHNOLOGY FOR MEGA-EXTENDED-REACH WELLS AT LIUHUA FIELD IN SOUTH CHINA SEA

To monitor the hole-cleaning condition and provide guidance during drilling,A new approach is proposed to monitor the hole cleaning condition and calculate the height and position of cuttings bed in extended-reach-wells.This approach was used to calculate and analysis the case of Liuhua 11-1-17 B3 ERW4 well.The calculation coincided with the actual conditions well,which showed that the approach in this study was workable and valuable in drilling engineering.At the same time,the study result indicated that cutting-beds with different heights existed during all drilling phases and the segment where the hole size was ?444.5 mm and the hole inclination was more than 45 degree had the highest cuttings-bed and became the most difficult segment for cuttings transport.The approach is simple and applied,thus providing guidance for field operation.