The Late Tectonic Movement Affects Hydrocarbon Reservoir Of Paleogene Saline Lacustrine Lake Deposit In The Western Qaidam Basin

Since half century,based on the theories of continental oil generation and multiple hydrocarbon accumulation zones,a batch of large and medium sized oil-gas fields like Daqing Field and Bohai gulf Field was discovered.These theories also guide to get the knowledge of late tectonic for accumulation,and developed greatly in recent years.The knowledge has obtained considerable development,but still staying in qualitative research stage.In fact,it is difficult to answer and proved that the power and process and pattern of the late tectonic movement on hydrocarbon accumulation,so the basic theoretical research in its infancy.In response to these increasingly complex exploration targets,Hu J Y academicians called for breaking tradition can transcend past and petroleum geological theory need a breakthrough.Qaidam Basin,as a typical product of Himalayan movement,is a hydrocarbon-rich salty inland plateau lake,within which not only developed in the late Himalayan experienced a significant uplift of the world's rare late hero Ridge tectonic belt also includes North Queensland fault zone and three Himalayan slope area of early movement has been formed for the construction of the sedimentary rocks in the late hydrocarbon accumulation studies provide a unique condition,through targeted research studies,regardless of the exploration areas expand or develop into possession of the theory are of great significance.Regard above as cutting point,we especially studied the model of Basin movement caused by late tectonic movements.And mainly analyzes the seismic data imaging of Pn-wave from structural physical simulation and latest three-component digital seismic network and mobile broadband digital seismic station records.At the same time,we pointed out some new understandings of Kunlun Mountain oblique extrusion and continuous marginal uplift and intrabasinal compression setting according to the regional cross-section analyzing.We also defined the evolutionary process of paleoclimate from dry heat to dry-cold and continuous basin salinization.By quantitatively evaluating hydrocarbon generation and petroleum accumulation effect under late tectonic movements,the results showed that firstly,on the basis of the gold tubes-autoclave pyrolysis experiments which reside in the international leading level.The hydrocarbon generation material,mainly born in late tectonic movement,commonly found immature-low high performance oil generation and relatively narrow window of exhaust hydrocarbon,Ro<0.8% get the maximum yield of Hydrocarbons conversion.Main oil window of this source rock is from 0.47-1.3.the peak of oil generation is around 0.7%,and a little earlier than the lacustrine organic matter.The yield is 1.15-4.58 times,comparing with freshwater lake source rock.Then,using the nation's leading represent dynamically,depositional new model of saline lacustrine basin braided river delta and single particle theoretical model has been successfully constructed.In the meantime,we point out the dynamic effect of saline environment helps fine grain carry long distance.Finally,after conducting the porous medium and rock reaction kinetics research,we defines two effect respectively is negative effects of saline environment,negative effect of reservoir characters and permeability of clastic rock reservoir affected by saline environment and porosity-increasing effect affected by generated dispersivity intercrystal porosity has been defined.After completing the evaluation of the hydrocarbon migration and accumulation effect affected by late tectonic movement.Firstly,we defined Paleogene hydrocarbon in Southwestern Qaidam has trait of multi-stage hydrocarbon expulsion and multi-domain distribution.Secondly,we created a new pattern of multi-stage superposed nappe structure and longitudinal default elicitation effect and available hydrocarbon supply,therefore,the conventional wisdom of early accumulation and late adjustment has changed.The new pattern of fault and unconformity remote migration and a wider range by mudstone,partial sealing by pitch and composite enrichment of multiple media has been created.Finally,we created the new perspective of oil and gas driven by super pressure and continuous distribution nearly source,in consequence,those traditional cognition of narrow phase belt and lacking sand body and compact reservoir and difficult to accumulation had broke through.In conclusion,the late tectonic movement stage is the main growth stage and complete period of Basin in our country.It is also the main formation stage and reorientation episodes of hydrocarbon reservoir.Therefore,this research has important academic and practical value for hydrocarbon accumulation.Original fundamental geology research of hydrocarbon formation and sand body controlled by late tectonic movement has the important meaning for development of salty inland plateau lake geological theory.It has made a major breakthrough in the exploration of Kunbei and Yingdong and Zhahaquan oil field.These theories also provide an important direction for the exploration of similar petroliferous basins.