Sequence Stratigraphy And Subtle Pool Exploratory For Palaeogene In Hui Zhou Depression

Huizhou Depression is a very complicated depression, in the background of extensional stress basins, after lots of structural actives, characteristics of faults is extensional and transtension. It trained architecture of depressions and bulges interstratified in the district. Huizhou Depression is one of Paleogene important oil-generatied depression in the Zhuyi trap. Wenchang group has good hydrocarbon potential, that hydrocarbon reservoir of deep layer was been found and the main oil and gas shows included this Depression. Depression tectonic layers present faulted depression, the basement with more depression, Paleogene it includes 13 small sag, Segmentation more apparent. From composite half-graben or half-graben system, the whole sag was divided into five half-graben system.Begin with the whole Hui zhou depression, the structure controlling the depositional system, and the applications of the principle and theory of sequence stratigraphy, the article analyses the function of the basin-controlled fault to the sequence architecture, the function of the lateral transfer zone to the provenance orientation and the function of the paleostructure and the paleotopograhy to the sands distribution , discusses sequence stratigraphy model and distributed and evoluting rule of the depositional systems and in sequence strata shelf in downfaulted basin. Depart from macro petroleum geology conditions, the article analyses s the basic condition formed subtle trap in Hui zhou depression . Analyses the reservoirs distribution by integrated utilizing generated condition of reservoir and predicts the advantageous subtle traps, provides a theoretical and scientific basis to the subtle reservoir exploration in Hui zhou depression .Based on the integrated analysis of cores, well logging, seismic data and other basic data, the sequence stratigraphy and the depositional systems of Paleogene of Hui zhou Depression are studied. The sequence of Paleogene is one 1st order sequence, and which can be divided ulteriorly into three long-term base-level cycles (2st order sequence) and 7 intermediate-term base-level cycles (3st order sequence). The sequence stratigraphic framework was established.Based on the analysis log and seismic facies shows and core information, to determine Paleogene depositional system types of this area, and distribution characteristics. Established faulted and fault sag period models of a half-graben as the basic unit of the Depression, Analysis various affection factors of the depositional systems and development.Huizhou Depression Paleogene faulted structure is transtensoinal sideway screen expression rift structure. Cenozoic originated five big tectonic movement, tectonic movement not only transformed the sedimentary environment, and decided to a new deposition form. Tectonic movements is the main factors of affecting the continental basin sequence evolution ,It directly determines formation and consumption of sedimentary basin accommodation, structure of screen time, the cyclical, Pulse-based direct control the sequence of cycles and sequence evolution of the internal development stage. In Hui zhou depression construction control sedimentary perform inaspects: as tectonic uplift movement, caused late strata of Wen chang and Enping group serious erosion, sedimentation existing relatively limited; regional tectonic movement, caused district sedimentary features can be roughly divided into three sections ,Hui xi half-graben, Hui dong,Huibei,Hui nan half-graben,Luxi half-graben, sedimentary characteristics of regional differences. Manifested in the Wenchang internal Depression period stretching direction, and En ping second grade the largest lake extensive face relocated . Structural adjustment area control source systems is also quite noticeable.studying Huizhou Depression, summed up the six common types of subtle trap in the pull-apart basin, Comprehensive analysis of the source bed reservoir and overlying formation, forecasted the favorable zone of subtle reservoir in Hui zhou Sag. hidden reservoir. Point out Huizhou 26 low-lying surrounding, Huizhou 10 low-lying, and Xijiang 24 and 30 low-lying is the focus of further exploration.