The Generation Of The Thick Sand Body And Its Great Impaction On The Distribution Of Oil Ang Gas In ? Sand Group Of The Third Member Of Qingshankou Formation,Daqingzijing Area,Jilin

Daqingzijing area is a favorable oil-bearing area in southern Songliao Basin,after years of exploration and development,the understanding is deepening.With the development and diversity of technology as well as the continuous encryption of well net,the previous cognition about sedimentary provenance system,sedimentary facies and hydrocarbon enrichment rules contradict with some new knowledge about this area.These restrict the further exploration for oil and gas.The reservoir of XII sand group in the third member of Qingshankou Formation has the best conditions in this area.The oil-test and mining-test result of a few wells turn out great.Consequently,in order to increase reserves and yield of oil field,it is necessary to clear the cognition of provenance,sedimentary system and reservoir forming pattern.Based on the study of the whole region,this paper focuses on the genesis of the thick sand body and the law of oil and gas accumulation.Based on sedimentology,stratigraphy as the guide,using the data about heavy mineral,core,drilling,logging and 3D seismic interpretation results,this paper analyzes the Vertical Separability of thick and bodies in 5 aspects such as the rhythm of logging curve,thin sandwich and core observation.The result shows that the thick sand body can be separated in vertical direction.Then according to the hierarchical accepted well standards of qians 8 and qian107,the stratigraphic classification on layers of the whole region was done.Therefore,the Sequence stratigraphic framework of XII sand group in the third member of Qingshankou Formation was established.Take the area sedimentology method as the guide,combined with 6 aspects information such as the heavy minerals and mudstone color for analysis.The result shows that the study area was controlled by three provenance system,which include the Northwest Branch of West Tongyu source,southwest Baokang source,Southeast branch of the southern Huaide provenance,Tongyu provenance had the maximum ancient slope,and it was the main source,the weaker one is Huaide while the weakest id Baokang.Through core observation,the main sedimentary facies in this area is Delta and gravity flow facies.Especially by the observation of thick sand body,the paper reckon that the thick sand body has different genetic characteristics,and they are mainly controlled by the differences of provenance system,mainly divided into: Estuary dam-wadi stacked,Estuary dam densely stacked,wadi-Estuary dam densely stacked and staging staked.According to the modern theory of delta sedimentology,the paper analysis the provenance and sedimentary traits,and set up the logging face model,namely delta front facies pattern,of the study area at the mercy of stratigraphic framework.Then,through the sedimentary recognition,the microfacies can be identified,which include underwater distributary channel,estuary dam,sheet sand.Based on these achievement,the paper determined the spread of microfacies in the study area.It shows that the spread characteristics of sandstone in the study area is controlled by the distribution of sedimentary facies,and the thick sand bodies mainly scattered with Tongyu,most Huaide and near souce of Baokang.On the basis of the above work,by using the theory of hydrocarbon accumulation in the region,based on the determined conditions of reservoir,the paper and group anatomy the dense well zone,the result shows that the study area mainly developed Fault lithologic reservoirs,Fault oil and gas reservoirs,Lithologic uplift oil and gas reservoirs and anticline oil and gas reservoirs while the Fault lithologic reservoirs id dominated.Oil source fault is prerequisite for the formation of oil and gas reservoir.The critical period of reservoir formation is the path of the ancient structure of the ancient structure,on which the traps near the most favorable accumulation,effective reservoirs,especially reservoirs with good reservoir properties,are the basis for the formation of oil and gas reservoirs,Under the condition of the development of fault system in this area,the effective blockage of fault is another key factor in hydrocarbon accumulation.