Biomarker analysis on carbonate reef reservoir using GC/GC-MS method.

Carbonate reservoirs have a very important role in oil and gas production in the world and generally, it comes from reef carbonates. Many were found in the Silur-Devonian, Cretaceous, and Neogene well. The majority of the carbonate reservoir rock has been facing changes in the primary pores because of the diagenesis processes. The diagenetic process causes some changes in the composition of the organic material inside the rock. Therefore, during the diagenetic process physical, chemical, and microbiological. In this paper, the hopane series biomarker analysis was used on the reef carbonate samples at several boreholes, namely B1-2, B3, and B4-5 in the Tikehau area, Tuamotu Islands in order to prove the presence of hydrocarbons and the effect of diagenesis. The gas chromatogram experiment results show a smooth and "gaussian" trend line due to the presence of iso- and anteiso-alkanes in the C25-C35 range. Except that, the stable configuration of the hopane biomarker is 17(H)α, 21(H)β. Then it can be concluded that the reef carbonate has undergone a maturation process due to high temperatures, namely the initial diagenesis process with the presence of abundant non-aromatic hydrocarbon compounds and n-alkane compounds from the area. [ABSTRACT FROM AUTHOR]