Fluid Variations and Their Controls Along the ACG Complex - Impacts on Development and Production

The fluids along the supergiant ACG complex show significant variations which can be attributed to the effects of intra reservoir processes. In particular evidence of biodegration has been observed within the shallower reservoirs of the Balakhany. This has been measured in elevated Pristane to Phytane ratios, declined wax content and elevated total acid number. Some of the Pererviv and deeper reservoirs appear to have also suffered from biodegradation but have been subsequently charged to mask the effect. The deepest reservoirs are unaffected by biodegradation and have high wax contents and low acid values. Understanding the variations in wax and acid number is critical for the effective production and transportation of these fluids. BP have embarked in an extensive geochemical study in order to monitor the physical changes in the fluid across the structures, and the processes responsible for these changes. This study has been targeted to maximize production and effective transportation of the fluid across the BTC pipeline.