Research On Characteristics Of Sedimentary And Petroleum Reservoir Forming Of Es3-Es4 In The Chenguanzhuang Area,Dongying Depression

The Chenguangzhuang area,located in the east of the southern slope of Dongying sag of jiyang depression.Based on the seismic data,log data,well test and production test data,also the theory of sequence stratigraphy,sedimentology and petroleum geology,we finished some studies of sequence stratigraphic framework,sedimentary characterstics and the factors of oil accumulation of Es3-Es4 formation.Finally we get some results below.Es3-Es4 formation of the Chenguanzhuang area is divided into 5 levels of third-class sequence.Based on the sedimentary characteristics of the lake basin in the equitime stratigraphy unit,the third-class sequence is divided into two-layered and three-layered sequence.The former is the structure of transgressive system tract and regressive system tract(T-R).The sandbody overlay is not obvious.But the latter is the structure of lowstand system tract,transgressive system tract and highstand system tract(L-S-T).And there are multistage sandbody overlays in the inner sequence obviously.Sources of the Chenguangzhuang area are mainly from Guangrao uplift in the south and the Qingtuozi uplift in the north-east.The types of sedimentary facies conclude the delta facies and lake facies in the study area.The delta facies can be divided into two subfacies:delta front and prodelta subfacies.And the former include distributary channel and distributary mouthbar microfacies.The lake facies include shore-shallow lake and deep lake subfacies.The Boxing sag in the west and the Niuzhuang sag in the north is the two major source areas,so the oil sources is sufficient.The types of source rocks is mainly include TypeⅠ and Type Ⅱ 1 and it’s evaluated as a good-very good one.The types of sandbody include distributary channel sandbody,distributary mouthbar sandbody,beach-bar sandbody and carbonate sandbody.They can be used as reservoir reserve oil and gas.There are three types of trap in the Chenguanzhuang area:lithologic trap,structural trap and structural-lithologic trap.And some more specific types such as lithologic updip pinching-out trap,fault-nose trap and fault-block trap.There are two big oil-gas migration pathways in the east and west side in the study area.And oil and gas can be transfered to the trap to become reservoirs trough fault,permeability sandstone or fault-permeability sandstone systems.