Publications

CiticSeram Energy Limited (CSEL) plans to drill several appraisal wells in Lofin area after the discovery of Lofin-1 and the second upcoming well will be a vertical well which is LOFIN-2 to reach Manusela Fractured Limestone to a depth of 17,800’ MD. Through learning from the problems encountered and research performed on the first well (LOFIN-1), we will see how improvements in cost savings could be achieved by using the high technology of pointing the trajectory, that is the Rotary Steerable System (RSS). Several tortuosity deviation analysis have also been successfully done using the “Novel Tortuosity Method”. During drilling operations of the previous well, LOFIN-1, there were several trajectory deviations due to formation dipping which led to high tortuosity and other problems such as micro dogleg due to the trajectory corrected by Downhole Motor. Because of the inability of maintaining the vertical trajectory due to this dipping, a sliding method by using Downhole Motor (DHM) would be required to correct it. The sliding might have been a solution for hole trajectory correction, but another problem appeared. When the sliding technique is performed, the drillstring (Top Drive) will not do a rotation and the only rotation that occurred is at the Bit which is generated from DHM itself by using mud circulation. As a result, the hole pattern will not be as smooth as expected. Therefore, extra time is required to do the back reaming operation. Referring to this problem, the usage of RSS will give benefits in terms of smoother borehole by eliminating sliding. In LOFIN-2, DHM was used in 12¼” hole section, and RSS has performed a significant role in drilling