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In recent years, a large number of light oil and gas reservoirs have been discovered in the paleogene sand sub-section of the northern belt of the Dongying Sag, and their oil and gas phase characteristics and reservoir formation patterns still lack in-depth understanding. Through the study of oil and gas geochemistry, fluid inclusion, and burial history-thermal evolution history, combined with crude oil cracking experimental products and oil and gas PPT simulation in the deep reservoir of the four lower sub-sections of sand, the deep oil and gas genesis, phase evolution and reservoir formation mode in this area are discussed. The results show that with the increase of the degree of cracking of crude oil, the critical condensation temperature gradually decreases. At higher pressures (20 MPa), the cleavage of the heavy hydrocarbon gas group was inhibited, the molar fraction of methane in the fluid composition decreased, and the critical condensation pressure of the fluid envelope decreased with nonlinear fluctuations. The characteristics of natural gas composition and carbon isotope show that the mirror plastoid reflectivity (R) of natural gas maturity parameter is between 0.9% and 1.5%, and the natural gas samples detected are the mixed causes of crude oil cracking gas and kerogen degradation gas. The absolute content of amantane and steroid detected in crude oil indicates that the deep crude oil samples detected are in a highly mature state, but are still in the early stages of cracking, and the crude oil cracking gas is moved upwards by the off-site crude oil cracking of the deep depression. The simulation of burial history, thermal evolution history and the uniform temperature of fluid inclusions in the reservoir show that there are mainly two stages of oil and gas injection in the sub-reservoir of the FS2 wellsha four sub-sections, namely crude oil (including kerogen degradation gas) charge at the end of the sand three-stage sedimentation stage and crude oil cracking gas injection from the deep reservoir in the early sedimentation of the Minghua Formation. Late high-maturity crude oil crack gas filling caused evaporative fractionation and gas washing, which was an important reason for the formation of deep light reservoirs in the region, and eventually secondary unsaturated condensate gas reservoirs and volatile reservoirs were formed [ABSTRACT FROM AUTHOR]

Thiadiamondoids are commonly found in crude oil. Because of their unique molecular structure and formation process, the thiadiamondoids are widely used in petroleum industry. The research progress and existing problems in identification, formation mechanism, thermal stability and application in oil and gas fields were summarized systematically. The results show that there are mainly two formation mechanisms of thiadiamondoids at present in crude oil, including hydrocarbon evolution of source rocks and thermochemical sulfate reduction(TSR)process, the first one can generate the initial small amount thiadiamondoids in crude oil, and TSR process can further form large amount thiadiamondoids; the higher the number of cages are, the higher the thermal stability of thiadiamondoids is, and the thermal cracking can occur in the high thermal maturity; thiadiamondoids are enriched with the enhancement of TSR process, thus can be regarded as reliable molecular markers of TSR process; δ34S values of thiadiamondoids can be changed by TSR process, which can reflect the genetic type of TSR process; the initial content and δ34S value of thiadiamondoids in crude oil without TSR process represent the characteristics of original source rocks, and can be applied to the division of crude oil group. According to the current research status, the specific formation mechanism and detailed thermal stability limit of thiadiamondoids are not clear; when the contents of thiadiamondoids are used to identify TSR process, it is necessary to combine sulfur isotope and other parameters; the study on thiadiamondoids is mainly focused on identification of TSR process, but the application on oil-oil and oil-source correlations needs to be further strengthened. [ABSTRACT FROM AUTHOR]

To meet the requirement of training engineering practice ability and innovation ability of undergraduate and graduate students, and to meet the requirement of discipline construction and the development of scientific research, unified laboratory system for teaching and scientific research in oil and gas migration and accumulation was explored and constructed. The laboratory aimed to integrate the functions of professional teaching and research, and made a reasonable planning on the basis of tlie target,then built a multi-level experiment innovation platform,and perfected the operating systems. The practice result showed that the platform has promoted the students' autonomous learning ability, practical ability,innovation ability and team cooperation spirit,and improved the scientific research level of tlie research team of resource exploration engineering scientific discipline,advanced development of the discipline "resources exploration engineering". [ABSTRACT FROM AUTHOR]