ONGC has recently become the first E&P Company in India to execute Under Balance Drilling. Drilling Services, Mumbai region has implemented Under-Balanced Drilling (UBD) pilot project in the Heera and Mumbai High fields. Drilling was initiated using base oil which was replaced by produced fluid as the drilling proceeded. Average ECD of 4.1 MWE was achieved during drilling of first well and which was further reduced to 3.9 MWE in second well. Lower completion was run and packer was set in flowing conditions in both wells.
Designing under balanced drilling process in which produced fluid was to be stored and circulated for drilling that also on an offshore rig was a colossal task. Each project activity was planned and executed with exhaustive deliberations. With full support from each of the many stake holders, project was designed and built to the execution stage. A Hazard Identification (HAZID) analysis for identification of Hazards was carried out through independent facilitator and all the observations of the HAZID were closed.
Team Drilling Services – Mumbai along with active stake-holders have completed two wells of the Under Balance drilling project with determined efforts in planning & execution, and paved the way for drilling and assessing depleted reservoirs simultaneously.