The Tectonic Characteristics Research Of HuangJinDai Oil Field In Bohaiwan Basin

HuangJinDai oil field has the type feature of complex downfaulted basin,affected by strike-slip motion,disrupts of district are complexity.Local structure with block of low amplitude,small area and fault nose structure.Oil and gas play are controlled by tectonic factor.So it is of great significance to determine fault characteristics and to analyze its relation with oil and water distribution.HuangJinDai oil field located in southern abyssopelagic zone of the eastern depression of LiaoHe basin,distribution to the northeast on the whole.With the dividing line of ErJieGou fault and JiaZhangSi fault,it can be divided into the western new slope belt,the central HuangJinDai fractured anticlinal structural belt and the eastern JiaZhangSi slope belt from the west to the east. The ShaHeJie formation and DongYing formation is rich in oil and gas,they have rich tectonic style and are the target stratum of this study.This article adopts the theory and method of structural geology.Using the seismic data, from the perspective of the tectonic characteristics,do a detailed study of tectonic characteristics,fracture characteristics,tectonic evolution process and the micro structure of the target stratum.Through this research,we achieved the following results and understanding:(1)This area has experienced the extensional stress field and the shear stress field in Paleogene,and the shear stress field was derived tension stress field and extrusion stress field which two directions perpendicular to each other.So with the complex stress field,this area developed abundant structural styles.We thought,the extensional stress field of early S3 formed the ErJieGou fault;The period of weaker stress field of later S3 and S1 formed the JiaZhangSi fault,with a extensional tectonic action of northwest-southeast;In the strong stress field of D period,due to the right-hand torsional stress field derived from east-west tension stress field and south-north compression stress field,formed the two direction of the fault,are the strike-slip tectonic deformation system,the maximum principal stress direction is nearly east-west,characterized structural deformation characteristics by right-lateral strike-slip of north-east,east-west extrusion and the extend of north-south,with longitudinal fold development;at the same time,as a bound of structural belt,ErJieGou fault make a change of the direction of the local stress field. Considering the change of regional stress field and tectonic belt,the influence of boundary of tectonic deformation superposition and complex deposit tectonic conditions are the reasons of the phenomenon of complex structure.(2)Tectonic evolution characteristics has an important control to the development of hydrocarbon source rock,reservoir and cover rock,and the movement,the assemble and the conserve of oil and gas.The major fault activity strongly in the period of S3,control the development of HuangJinDai deep zone.The environment of the middle submember of the third member of the ShaHeJie formation is lake deposition,developed pure and thick mudstone, is the major hydrocarbon source rocks. In the later S3,the area uplift,lost the period of S2,parallel unconformity with the overlying strata.The reservoir physical property are be good improved near the unconformity surface.The S1 period is steady,slow formation sedimentation,extensive development of fan delta sedimentary system in this region,with better properties,are the major reservoir of this distinct.DongYing period for strong strike-slip period in this area,at the same time is also a large amount of hydrocarbon expulsion period of hydrocarbon source rocks.The fault developed in the S3 period actived again.Channels for vertical migration of oil and gas due to the communication with hydrocabon source rocks.The new fault became the channel which oil and gas send from the reservoir of S1 to that of D.Bucking folds formation has a relative elevation difference.Powered for lateral migration of oil and gas.The direction of the high point is the advantage direction of the oil and gas migration.The tectonic setting,fault stop activities at the end of D.From oil and gas migration path towards a provide shelter for oil-gas accumulation.Complex fracture system and strata fold made structural trap very developed,provided gathering place for oil and gas.The reservoir of S1 developed few fault.Mainly for the anticline traps.S3 and D are mainly fault nose trap and fault block traps.