Accuracy of Condensate to gas ratio (CGR) based on fluid sampling analyses.

Abstract

ABSTRACT

Accuracy of condensate to the gas ratio (CGR) is one of the most significant issues in the petroleum industry. In this study, Ormen Lange field was the case study for checking the accuracy of CGR based on fluid samples from different fluid sampling methods. By analyzing the cleanup test data of nine development wells which were provided by EXPRO from 2007 to 2009, the CGR of each development well was corrected with regards to the total volume correction factor (TVCF) of intended development well. In addition, corrected CGRs were normalized based on missing gas volume of stoke tank oil from cleanup test process due to the missing gas development wells. Hence, by checking the validity of average normalized CGR from the cleanup test with actual production data, liquid and gas phases of test separator sample (cleanup test sample) were recombined together with validated normalized CGR by PVT.SIM software. Consequently, this study showed that the measured CGRs of collected samples by MDT method needed further investigation due to the fact that the average relative error of CGRs from MDT samples was approximately 40% as compared to the average CGR of DST and test separator samples (cleanup test sample). Besides, this significant relative error can result in possible consequences for planning and fluid modelling.