Evaluation of oil shows in Middle-Miocene at block 02 of cuu long basin based on some of well data

Abstract

Up to now, reservoir system in Cuu Long basin have been known including Pre-Tertiary fracture basement, sandstone of lower-Oligocene formation (Porosity from 12 to 16%, permeability from 1 to 250 mD), sandstone of upper-Oligocene formation (Porosity from 12 to 21%, permeability from 2 to 26 mD), sandstone of lower-Miocene formation (Porosity from 14 to 28%, permeability from 1 to 1300 mD). However, the result of evaluation of analysis of data at block 02 is very good oil shows in sandstone of middle-Miocene formation, the gas oil ratios of this oil is from medium to high, predominantly light oil and hydrocacbon have not changed yet. The result of analysis of core samples and petrophysis data of sandstone of middle-Miocene is that porosity is from <10 to 31% and permeability is from 100 to 3066 mD. Following geology structure and combining data of seismic, petrology, stratigraphic and geochemical source rock indicated oil of middle-Miocene was relative with lower-Oligocene and upper-Oligocene. These rocks contain abundant of organic matters that could produce hydrocarbon well. Then, hydrocarbon migrated and accumulated into fold traps in lower and middle-Miocene. Proven reserves 1P (P50) of two reservoir sets BII .2.20 và BII .1.10 is 70.7 MMbbl and proven plus probable reserves 2P(P50) of two reservoirs BII .2.20 và BII .2.30 is 73.11 MMbbl. Discovering oil and gas in middle-Miocene at block 02 openes up new target in exploration of oil and gas field in margin zones of Cuu Long basin.