Accumulation Models of the Oil Pools of Block XXI of Tamsag Basin in Mongolia

Abstract

This document explains different tectonic styles and sedimentary fillings give rise to the different accumulation combinations and accumulation models between the south and the north frogs of East Subsag of South Buir Sag. The Tsagaantsav Formation oil pools, subject to the rupture of the fault-period tectonic layers, has developed multiple types of traps including reverse fault blocks, fault noses and drag anticlines. They are close to the oil-generating sags, in the indicator areas of hydrocarbon migration where hydrocarbon pools, particularly tectonic-controlled pools, are easily formed. The lithology and physical property play an important controlling role over the formation of oil pools with complicated oil-water distribution relationship. The constant and the late active ruptures as longitudinal hydrocarbon migration pathways, together with the sedimentary sands of multiple genesis types, have given shape to the multi-formation lithologic, lithologic-tectonic or tectonic accumulation combinations.