Petrophysics and rock physics using VTI model for low permeability and high porosity reservoir in CCS Gundih gas field pilot project, Indonesia

Abstract

A pilot Carbon Capture and Storage (CCS) project in Indonesia is planned to be implemented in Gundih area, Central Java Province in Indonesia. Prior to conducting CO2 injection, reservoir characterisations have to study thoroughly to assure that the reservoir is to meet with CCS standard requirements. The Jepon well in the Gundih fied was proposed as a suitable site for CO2 injection. The decision was made to proceed with a comprehensive site assessment and geological modelling of the Jepon area. This site was selected based on the reason the presence of a potentially suitable reservoir (Ngrayong Sandstone) and primary and secondary seals (Bulu Limestone and Wonocolo claystone). Using logging data, petrophysics and rock physics model are used to evaluate potential of the CO2 injection site. Permeability results from petrophysics calculations and recent injection tests show very small; whilst porosity is relatively high. This can be caused by fractures mostly are not connected. Hence, rock physics for the reservoir is evaluated and modelled as anisotropy or Vertical Tranverse Isotropy (VTI) in which fractures with preferred orientation. Stiffness calculations for VTI medium with different aspect ratio shows consistent with low permeability result.

A review of global carbon capture and storage (CCS) and carbon capture, utilization, and storage (CCUS)

“…To achieve the national CO2 reduction target, the 'Comprehensive National CCS Plan' was established by the National Green Growth Committee in 2010. The reduction target was set at 37% of the BAU in 2030 in June 2015 [22] [26].…”