Hydrocarbons in the basement of the South China Sea (Vietnam) shelf and structural-tectonic model of their formation

Abstract

Research of genesis of hydrocarbon accumulations located within pre-Cenozoic basement of the South China Sea shelf (Vietnam) presented. Formation of hydrocarbon deposits is confined to the protrusive massifs of granites that have undergone structural and tectonic processing at the stage of prototectonics and postmagmatic tectonics. The totality of post-structure-forming processes led to a change in the viscosity properties of rocks, to their tectonic and material heterogeneity and stratification and, as a consequence, to vertical and lateral redistribution in space with the formation of granite protrusions. The mechanisms of formation of voids and oil and gas traps within the protrusions are considered. Based on the similarity of the geochemical characteristics and biomarker parameters of the oils and organic matter in the Oligocene-Miocene sediments and in the basement rocks, a conclusion has been made about the organic nature of the oils in the basement of the shelf of the South China Sea (Vietnam). Possible mechanisms of migration and accumulation of hydrocarbons in basement rocks are considered. It is confirmed that the formation of hydrocarbon deposits occurred due to lateral and downward migration of hydrocarbons through the contact area from the Oligocene-Miocene source rocks into crystalline massifs — into voids and increased fracture zone in the protrusions.

Strategic management of human resources in modern conditions: a case study

“…Next, we shall analyse the training of personnel at Surgutneftegaz PJSC in 2017-2018 (Table 2). The number of employees taking part in training events at Surgutneftegaz PJSC in 2017-2018 increased by 2.3 thousand people, the share of employees taking part in training events in the total number of personnel increased by 2.2 percentage points, although in comparison with PJSC Rosseti and JSC Rosseti Tyumen it is much loweronly a third of employees annually improve their level of professional knowledge (Kerimov et al, 2019).…”

Cretaceous-Cenozoic Hydrocarbon Systems of the Eastern Arctic Seas

“…Formation of the gas or oil and gas accumulations is possible under the condition of prevalence of the kerogen type III in the composition of the producing rocks. Based on the results of modeling formation of the gas accumulations is expected in the central and southern parts of the Laptev Sea irrespective of the type of the kerogen in this part of the section [5].…”

“…Nevertheless, some general and quite simplified vision of distribution of the water areas, where existence of optimal conditions for preservation of the deposits is possible, can be obtained from the data in relation to a rather scarce grid of seismic observations and paleogeographic reconstructions performed as the reviews [6].…”

Postmagmatic tectonics of basement granites of the Far Eastern seas of Russia

“…It is currently accepted [1][2][3][4] that two main features are characteristic for granite massifs: formation of dome structures and intensive structural processing of rocks. The study of postmagmatic granite structural geology within various regions of Eurasia (the Caucasus, Tien Shan, Gobi Altai, Baltic Shield, the bases of the Far Eastern seas, etc.…”

“…Resulting from the above processes, a significant part of the granite bodies volume is converted into a cataclosed mass. Considering the variety of scales and forms of structural processing of rocks, a feature of granites is the disintegration at the level of mineral grains and their communities, which is associated with their composition and primary structure and which reflects the rheological exclusivity of granites relative to other base rocks [2]. Upon entering the base, the granite bodies do not become its passive components, but are advanced, sometimes following a significant (tens and hundreds of millions of years) time interval after crystallization and cooling, to higher horizons of the earth's crust relative to the primary occurrence and form dome structures expressed in the surface of the base and deposits of the overlapping cover.…”