Volumetric estimation and OOIP calculation of the Ronier4 block of Ronier oilfield in the Bongor basin, Chad

Abstract

Ronier oilfield is located in the Bongor basin, lies to the southeast of Chad Lake in Africa is about 300 km from the southeast of capital N’djamena. The Bongor Basin is located at the crossing part of the Central Africa rift zone and the West Africa rift zone. Is a Mesozoic-Cenozoic rift basin developing the effects of Central Africa Shear zone? The successive discovery of well Ronier 1 in 2007 and well Ronier 4 in 2008 has indicated that they have a potential for commercial exploitation. The reservoir is a braided river delta front facies sediment with a proportion of 78% of sand and 22% of shale. In the actual work, Stochastic Gaussian Simulation algorithm under the phase control based on the collocated co-Kriging is adopted and the models of porosity, permeability and saturation are established. The porosity distributed mainly between 17 to 27%, and 19% on average. Due to the higher logging interpreting oil saturation, 60–72%, which conflicts with the irreducible water saturation of core obtained in the laboratory, a conservative value of 60% was used as the oil saturation of the OOIP calculation this time. The geological models were created this time mainly for Block Ronier 4, which include: KublaI-1, KublaI-2, Mimosa I and Mimosa II. The Original Oil in Place is 321 MMSTB, while the Gas Initial in Place is 514 MSTCF will be developed.