Study On Fault Development Characteristics Of Diannan 8 Well Area In Donghaihaizi Depression

This paper selected the Dinan8 Areas of Dongdaohaizi Depression as the research object,based on seismic data,guide by structural geology theory,from the aspects of structural analysis,and use a combination of structural geology,seismic geology and so on,and used the tectonic interpretation of seismic sections in the study area and the surface geological investigation,combiningprevious research results,analysis the structuraLCharacteristics,fracture developmental features,structural styles and trap characteristics of the whole research areas.Further clarifies the relationship between structure and oil or gas.And obtained the following main results:(1)Combining regional evolution characteristicand previous research results,preliminarily suggests that research area experienced three structural movements in geologic history:Hercynian period,Indosinian period,Yanshan period.The compress-torsional faults forming Permian-Triassic period controlled the structural framework which could summarize the depression between two uplifts,and the compress-torsional faults in the depression mostly extend to source rock in Permian even in carboniferous,and this kind of faults are favorable hydrocarbon migration paths.(2)Controlled by the Kelamaili right spinning torsion stress,there are series of Hercynian period-Indosinian period left spinning torsion faults developing at northern slope of Dongdaohaizi Depression.Controlled by this type of faults,there are developing 4 rows of compress-torsional fault belts from south to north which scales were reducing gradually at Permian system of Dinan8 areas.(3)With the rise of theKalamaili Mountain,there are several NE compress-torsional faults belt that emerged,and those faults connect with Dishuiquan faults with acute angle,anDFormed a series of fault-noses or fault-block trap in Dian8 areas which formed by the intersection between the mainly compress-torsional fault and secondary fault.(4)Permian is the main objective of the study area layer system,among them,the reservoir types of Wutonggou group is primarily fault-block type,and its characteristics of reservoir including nose-shaped uplifts controlling migration,fault blocks controlling accumulation,fracture and high-quality sand controlling production.(5)Through comparing the crucial hydrocarbon reservoir forming stages of Wutonggou group in Permian and structural feature nowadays,we find that the nose-shaped uplifts developed continuously,theresevior condition is more favorable,so this is the favorable region of oil and gas exploration in next step.