Study On Fine Structure Interpretation Of Lower Minghuazhen Formation In Southern Liubei Oilfield Of Raoyang Sag

After more than half a century of exploration and development,now the progress of increasing production is slow and difficult on the main oil production layer of Raoyang Sag.According to the field test data of oil production,the oil and gas resources in Neogene are shallow and the reservoirs permeability are good.Therefore,in order to increase production steadily and increase proven reserves,it is necessary to shift exploration targets to shallow Neogene reservoirs.Among them,the exploration and development level on Lower Minghuazhen Formation is relatively low,and there are still some problems.For example,the division of sequence stratigraphic units in the target layer is not precise enough,the scale of fault distribution is not clear and so on.Therefore,it is necessary to study the fine structure,find out the position of hidden traps,and find out the rules of reservoir distribution to guide the forecast of favorable targets.In this paper,the high resolution sequence stratigraphy is guidance,using the method of well seismic combination to combine logging data and seismic data,unify the divisions in depth and time domains,and establish a more accurate and reasonable stratigraphic framework.Four secondary cycles were divided in Lower Minghuazhen Formation in the study area.Through the Section Interpretation Technology,Horizontal Slice Technology,Horizon Automatic Tracing Technology and 3D Visualization Technology,fine interpretation of each cycle interface and identification of some faults of four or above level can be made.Combining the Ant-tracking Technology,Curvature Technology,Coherence Technology,Fault Dip And Azimuth Detection and Fault Edge Detection Technology,faults of lower level can be interpreted,to make the interpretation results more consistent with objective rules and ensuring the reasonableness of interpretation results.Based on the acoustic log and the result of horizon interpretation,the velocity model is made to make the time-depth transformation,so that we can get each structure plane of layer interface in depth domain and establish the structural model to guide the analysis of the structural characteristics and the tectonic evolution.By studying the relationships with fault plane,fault activity,fault sealing,fault combination feature of plane and section within the known reservoirs,the oil and gas accumulation pattern of Lower Minghuazhen Formation in study area has been obtained,and the favorable target positions are predicted.Based on the factors and criterions that can be used to predict the favorable target positions,It is predicted that within the structure model,the left part of block 8 and the right part of block 9 have great potential for oil and gas resources in the third and fourth secondary cycle of Lower Minghuazhen Formation.