RESERVOIR CONTINUITY ANALYSIS UTILYSING GAS CHROMATOGRAPHY FINGERPRINT IN THE ‘S’ OIL FIELD, SOUTH SUMATRA BASIN, SOUTH SUMATRA

• Main Author: AGUS BUDHI NUGROHO, TIDAR
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69611
• Institution: Institut Teknologi Bandung

Problems often faced by the oil field 'S' are the nature of different crude oil physical property in the producing wells. Drilling often met dry hole nearby producing wells, so that field development becomes difficult to plan. The use of fluid geochemistry is useful accompanying the more traditional reservoir geology and production-engineering tools, such as well log and well tests. The result of crude oil chromatogram gives more understanding and complete reservoir characterisation. The chromatography technique can be applied in the early stages of field development as well as in the later stages of the reservoir management. This thesis describes the technique of reservoir characterization using gas chromatography and illustrates the case histories from the ‘S’ field, Musi Platform, South Sumatra Basin in the South Sumatra extension region. From visual perception, the crude oils produced in ‘S’ field have some differences quality including color and viscosity, which generate suspicion of the existence of reservoir continuity problem. To understand this problem, a laboratory research utilizing gas chromatography analysis was applied to clarify the reservoir character. In this study, nine crude oils from 'S' oil field have been analyzed using gas chromatography to identify the reservoir continuity among producing zones at Baturaja Formation reservoir. Data analyses and interpretation distinguish seven crude oil samples (S-D3, SD4, S-04, S-D1, S-D2ST, S-F1 And S-F2) are light oil, while two crude oil samples (S-B2 And SG1) are moderate. These oils were generated from terrestrial source rock comprising of mixed Type II and Type III kerogens. Minor alteration including biodegradation involved in these crude oil samples. Eight crude oils (S-B2, S-D3, S-D4, S-04, S-D1, S-D2ST, S-F1 and S-F2) were slightly evaporated during fractionation, while S-G1 was minor biodegraded. The analyses result of interparaffin between nC9 and nC18 shows that these nine crude oil samples from ‘S’ oil field have a relatively similar fingerprint, indicating the occurrence of fluid communication among the oils. Therefore, it appears that the reservoir in the ‘S’ oil field is interconnected.