Research On The Relation Of Stress Evolution And Hydrocarbon Migration-Accumulation In Dongying Depression

Taking the complex fault-block group of Dongying Depression as study carrier, the depression stress field, fluid potential field model and hydrocarbon migration-accumulation model under the control of stress field's evolution are estabalished using finite element theory, which can guide the exploration and development of complex fault-block oil reservoir theoretically.Used the multi-disciplinary theories and methods,especially computer technology, stratigraphy, seismic well logging, reservoir engineering and stress field evolution, fluid migration potential field to reveal the Dongying depression's reservoir characteristics, formation mechanism and distribution pattern.This study does numerical simulation research of the hydrocarbon migration-accumulation in the Dongying Depression depression using the theory of stress evolution.The finite element model of stress field in Dongying depression of oil-generating organic matter filling period is established through the paleo-stress recovery, the results of simulation show that: during the late Cenozoic of Ed, under the influence of the Dongying screen movement in the Himalayan tectonic activity,oil and gas were filled on a large-scale for the first time ,the study area located in the right-hand pressure torsion stress field, which macro-controlled the oil and gas migration.This research establishes the potential field model of fluid flow from the end of the Ed to Es3 section and the current vertical fluid flow potential model, reveals the spatial distribution and evolution pattern of the fluid flow potential field since the end of the deposition of the Ed; establishs the present fluid flow potential model with depth trend, points out current fluid migration trends, which are of great significance for oil-gas forecasting and exploration and development of oilfield.The stress performed differently in different geological periods: played a leading role in the the strong tectonic activity period and supporting role in the calm tectonic activity period . The stress field of Dongying depression during oil-filling period controlled of the current oil and gas spread directly.Established the Dongying Depression-forming pattern of complex fault block oil reservoir, proposed a study on the control of a complex fault zone fault block oil reservoir, parallel faults and associated fault-controlled fault block oil reservoir, as well as the lithology of the formation of fault block within the reservoirs.Establishment of complex fault blocks Dongying accumulation model: faults control complex fault block oil reservoir; parallel and associated faults control fault block oil reservoir; lithologic reservoir are formed within block.Revived the paleo-stress and simulated the stress of the period of the end of the Ed sedimentary and Ng sedimentary, its distribution pattern shows that the study area Lijin, Niuzhuang, Minfeng sub-depression stress values higher, and in the central sub-depression segmentation fault belt, the region near the fault and its associated backbone fault, the stress value is low; the same tectonic belt, the deep-seated stress value is high, shallow stress value is low, the stress in the fault junctions easy to extremely low values of oil and gas migration.The advantage of the hydrocarbon migration-accumulation place, which has been confirmed that the current exploration and development.The numerical simulation showed that the low potential zone corresponding to the stress field in low stress areas, are the advantages of oil and gas migration reservoir sites.