CROSS-WELL SEISMIC APPLICATIONS FOR SEISMIC RE-INTERPRETATION AND RE- LOCATION INFILL DRILLING WELL X-30, BUNYU FIELD, EAST KALIMANTAN

摘要

Bunyu Field is oil and gas field that located in the most southeast Bunyu Island, East Kalimantan, Indonesia. Geologically, Bunyu Field located in Tarakan sub-basin, which is part of the Tarakan Basin. Bunyu Field operations were started by Bataafsche Petroleum Maatschappij in 1901 by drilling B-001 to B-016 wells. Starting in 1968, the field was operated by PERTAMIN, which later renamed as PERTAMINA. Oil Production of Bunyu Field reached its peak production at 10,510 bopd in 1959, since 1976 oil production of Bunyu Field starts to decline each year until it reaches around 1,000 bopd in 2009. Oil Production of Bunyu Field then increased to 5,441 bopd in 2010 from L-layer at X-18 well on Bunyu Nibung Block. The success of oil production at X- 18 well encouraged to undertaking the Geology, Geophysics and Reservoir study more intensive, one of which is cross-well seismic acquisitions in 2011 to determine the model structure and sedimentation in Bunyu structure which previously less known because of the limitations quality 3D seismic data that was acquired in 2005. The drilling results of X-28 well in July 2011 did not reached the oil target layers as of other oil wells in Bunyu Nibung Block. This results lead to reinterpret the seismic especially for fault reinterpretation to have a clear boundary between Bunyu Nibung Block as block of oil producer and Bunyu Reuris Block as block of gas producer. Reinterpretation results from cross-well seismic data with 3D seismic data (reprocessing at 2010) showed that there is a major fault that clearly separates Bunyu Nibung Block from Bunyu Reuris Block, as seen from the drilling results of X-28 well. The presence of this fault caused the need to relocation of next drilling well X-30 from its previous location that is lays in fault region. The results of the X-30 drilling wells showed the discovery of multiple hydrocarbon prospects in F, J, M, and N layers. Perforation in N layer produces oil with Qoi 1,655 bopd and gas 0.6 MMscfd.