Perpustakaan Digital ITB

One of the largest natural gas fields in Indonesia is Natuna gas field. There is a tremendous gas deposit laying on the reservoir of natuna field, estimated to have over 200 TSCF, making Natuna the largest gas reserve in South East Asia. The produced gas from Natuna is composed predominantly of CO2 (71%), and contains 28% CH4 and also 1% other gas. This large value of CO2 can be utilized to Enhance Oil Recovery or Enhance Coal Bed Methane Recovery. Despite the large potential of Natuna gas field, the utilization of this resource is quite small since the dominant gas is CO2 so it needed to be separated first. The idea of this study is to directly utilize raw natuna gas as injected fluid to enhance coal bed methane recovery. The recovery of coal bed methane is quite small since it is affected by the coal seam pressure and diffusion rate that makes the available gas in the reservoir can’t be fully recovered. By injecting gas to the coal seam, the trapped gas on the reservoir can be liberated. Commonly, the injected gas is CO2. The injection of the injected gas might increase methane recovery while reducing gas emissions. This study will show the utilization of Natuna Raw Gas to increase the recovery of Coal Bed Methane and compare to the common injected gas for enhancing coal bed methane recovery which is CO2 considering technical and economic evaluation aspects. In the work presented here, the net present value is used to do the economic evaluation to optimize the economics of the project.