The Comprehensive Evaluation Of Hydrocarbon Preservation Units In Modifying-type Basins Of Sea Facies In South China

The marine sedimentary basin of the Mesozoic and Paleozoic has not been exit in southern China, the basic property of tectonics-sediment entity of nowadays survival is the polycycle of congruence tectonic reworking type residual basin. Now, the marine basins, characterized by the powerful mountain building within continents and the departing interactions between mountains and basins in the Yanshan-Himalayas period, losing their prior primary characters and with the present tectonic framework in a state of pieces, are the re structured overlapping multi-cycle basins. Through the exploration of recent 10 years, it has been proved that holding fast to the key point of "the oil and gas preserving conditions", the paper defined clearly the concept of "Hydrocarbon Preservation Unit" which has the essence of the concepts of "wholly preserved system" and "oil and gas bearing system". HPU is in fact a researching system of reservoir forming, focusing on the preservation conditions. The concept can be applied to the oil and gas bearing basin (or depression) where the structures are complex, the water systems are active, and the faults are common. By the study of HPU, oil and gas explorations can be guided under the concept.The whole exist closure preservation condition can be described (inversion) under the studies of the tectonic movement , the time of the reservoir formed, the region cap rock preservation condition and the hydrogeological conditions, reservoir organic aspect, fluid nature and physical chemistry characteristics, we can estimate whether the petroleum preserve until today. The whole closure system, the trap and the oil gas-bearing goal formation form 3 basic integrant pan of oil gas-bearing preservation unit. On the basis of the study on five oil gas-bearing field in southern marine facies, the oil gas preservation unit and the non-preserved unit based on the division by region cap rock, hydrocarbon source validity and whether exists oil gas-bearing system.: As the standard of the relations between the coverage cap rock constructs and the oil gas-bearing system, the author has divided the oil system into four styles: the continuing, the reconstruction(contains deposition reconstruction and structure reconstruction), the maintenance and the remaining (subdivides disintegration to be remaining and structure dismemberment).The author take the basin structure evolution as the main clue, according to the factors of oil gas preservation unit integrant part, region cap rock, sufficient hydrocarbon source, reservoir, trap, the formation and the distribution of the nowadays oil gas-bearing system can be known. The whole exist closure preservation condition can be described (inversion) under the studies of the tectonic movement , the time of the reservoir formed, the region cap rock preservation condition and the hydrogeological conditions, reservoir organic aspect, fluid nature and physical chemistry characteristics. The evaluation of oil gas-bearing preservation unit is under studies of the cap rock, magmatic activity in the geological condition and the oil gas...