Publications

The condensate banking can be detected in certain gas reservoir/field. This evidence is also discovered in “M” gas field which is consist of several structure i.e.: “M” structure, “D” structure, etc. The “M” structure were found by drilling an exploration well (M-1) in 1980’s and start to develop since October 2009 by drilling an apprasisal well (M-2) near the M-1 well. The DST was performed in this well including the PBU test which programed to shut-in the well for more than 7 days which was the first time ever in this area and gave a radius of investigation of more 200 meter throught out the reservoir which was given a better impact to the proven continget resources calculation. The condensate banking phenomena is observed from M-2 well after running the DST analysis result which can be derived from the derivative plot analysis. It is also found in several well in “D” structure from the DST data analysis and evaluation. After all, the occurrence of condensate banking will have an impact to the production performance and recovery in the development phase of this field. This formation of liquid banking in the reservoir of gas production well can cause a severe loss of well productivity and low gas recovery of the well/field. When this happens in the gas production well, three regions will be formed in the vicinity reservoir surrounding the well, i.e.: • Outer Region: it is away from the wellbore, which has the initial liquid saturation, • Intermediate Region: there is a rapid liquid saturation increase which is associate with the gas relative permeability decreasing. • Inner Region: which is closer to the wellbore, where the liquid saturation reaches a critical value. This paper will discussed this phenomena based on the DST/well test data analysis and evaluation from several well case study in “M” field/structure.