К ВОПРОСУ О ПРИРОДЕ И МЕХАНИЗМЕ ФОРМИРОВАНИЯ ЗАЛЕЖЕЙ УГЛЕВОДОРОДОВ НА ШЕЛЬФЕ ВЬЕТНАМА

Abstract

The paper presents the results of the study of main factors determining conditions of formation and distribution of oil and gas deposits within the Cenozoic sedimentary cover and Precenozoic granite basement of the Vietnam shelf. The structural and tectonic model of the Kyulong basin constructed by the authors allows to reveal the conditions of formation of regional and local structures in the sedimentary cover containing hydrocarbon deposits; mechanisms of hydrocarbon traps emergence and hollow space (collectors); genesis of hydrocarbons, including the hydrocarbons existed in the basement rocks; the possible mechanism of migration and accumulation of hydrocarbons in the basement rocks. The traps which are real or potential reservoirs of hydrocarbons in the body of a crystal socle are widely developed. The structural and tectonic processes in the basement itself resulted in the development of positive morfostructures (domes, protrusions) the cores of which are made of disintegrated (granulated) rocks of a crystalline cap. In order to reconstruct the chronothermobaric conditions of occurrence and evolution of hydrocarbon generation centers and to restore the conditions of formation and distribution patterns of oil and gas accumulations on the shelf of Vietnam, three-dimensional modeling of generation and accumulation hydrocarbon systems was performed using the basin modeling technology and PetroMod software (Schlumberger, Ltd, USA). Studies of hydrocarbon biomarkers of oil fields in the Kyulong basin, including those located in the crystalline basement have shown the similarity of biomarker parameters of oil and organic matter, which demonstrates the organic nature of the oil fields of the basement on the shelf of Vietnam