Publications

Langsa TAC, which is located 50 km offshore of East Aceh in water depth of 100m, resumed production at the end of 2004 at around 5000 BOPD. It took only 11 months to have oil in production since the TAC was awarded to the operator, Medco Moeco Langsa Ltd. (50/50 Joint venture of PT Medco Energi International Tbk and Mitsui Oil Exploration Co., Ltd), in January 2004.The operator drilled two new wells and conducted one well workover. The first well was spudded in late July 2004 and the rig was released on the third week of October 2004. The production system consists of three subsea wells, flexible risers and umbilicals plus Floating Production Storage Offloading (FPSO) facility.The reservoir is fractured carbonate formation, which has good productivity (2000-4000 BOPD/well) but due to the large permeability in the fractures with relatively low formation pressure, operator encountered excessive lost circulation during drilling.The reservoir fluids contain gas with high CO2 and H2S, the latter requiring serious attention and caution.In this paper, the authors will introduce the characteristics of Langsa Field and will focus on the method dealing with major lost circulation in the productive horizon by setting a permanent packer with ceramic flapper valve.This method will be applicable to complete wells which encounter extensive lost circulation in the reservoir section. On top of this, the model of the developing marginal field, we believe, will increase the investor interest for challenging development of other marginal fields in Indonesia.