Research On Tectonic Characteristics And Regularity Of Forming Reservoir In Wangji Oilfield

On the bases of regarding tectonic geology,stratigraphy,basin structure analysis as the theory instruction, starting from the analysis of the regional structure background,sedimentary characteristics and the results of previous researches,and make full use of seismic,well logging,oil testing and other relevant data in study area,based on the analysis of seismic data interpretation, division and correlation of reservoirs,structure map and tectonic style,analyzing the structural characteristics of Wangji Oilfield.Wangji Oilfield is a nose structure with graben combined features which is cut off by some NE trending faults, the main local structure is fault block,secondary folds do not develop.Influenced by the regional extension,the structural styles in WangJi area are extensional tectonic style,with strike slip tectonic characteristics.NE-SW trending extensional stress play an major role before the 2nd member of hetaoyuan formation deposit,tectonic deformation affected by the activities of Tanghe-Liyuan faults,Tanghe-Liyuan faults are mainly normal faults with a left lateral slip component,upper plate tectonic deformation caused by fault activity,during the deposition of the 3rd member of hetaoyuan formation,the nose structure start to take shape.From the sedimentary period of the 2nd member of hetaoyuan formation to the end depositional stage of LiaoZhuang Formation,the tectonic stresses field take changes,mainly in the NW-SE extension. Affected by the oblique extension, Miyang-Liyuan faults are mainly normal faults, with a right lateral slip component,fault activity causes upper plate tectonic deformation and take modification to the previous structures.At the end deposition period of Liao Zhuang Formation,regional uplifting takes place, NW-SE trending extensional stress lead upper plate of the boundary fault to fault block tilting,normal faults developed,stratum suffered strong erosion,early structural traps are remodeled and formed complex nose structure and fault block.The accumulation model of Wangji oilfield takes Biyang sag center as oil source, the nose for channel, the delta sand body as reservoir, the cope of river bay mud and closed fault as overlying strata.The favorable sites of Wangji Oilfield one is a favorable tectonic area,another is adjacent to fault with good overlying strata should be the favorable position. These parts should be in the wings of Wangji graben and mainly in the east.