Correlation of Surface and Subsurface Geological Data Approach to Determine Depositional Facies of Bekasap Formation in Sungai Kuning, Rokan Hulu Riau - Indonesia

Abstract

Abstract. Reservoir rocks are exposed in Eastern part of the study area which one of
major reservoir of oil and gas field founded in Sungai Kuning, Rokan Hulu, Riau.
Surface and subsurface lithological data should be correlated to identify the
connectivity because it has an impact and affects the productivity of hydrocarbons. This
study focuses on the understanding of depositional facies by correlating surface and
subsurface data in Central Sumatra Basin. The methods used was by obtaining surface
geological data, micropaleontology and petrography laboratory analysis, characterize
depositional facies and geological structure analysis. The subsurface geological data
acquired from core and wireline log data of MDL-31Well X Field, such as analysis of
lithofacies, electrofacies and depositional facies. So, by the conclusion, there are four
facies associations which are Distributary Mouth Bars, Tidal Channel, Upper (fluvial)
- Middle Estuarine, and Lower (tidal) Estuarine Channel. From integrated analysis,
reservoir lithology on surface and subsurface having similar lithological characteristics
and interpreted to be deposited in same depositional environment.