| Fan delta facies reservoir is a kind of very important oil and gas reservoir,which has always been the focus of many scholars and researchers.At present,the domestic research on fan delta facies reservoirs is relatively low,especially the research on fan delta front reservoirs is less,which is difficult to meet the needs of such reservoirs in the actual production and development process.The fan delta front sand body is close to the source area and the sedimentary thickness is large.The vertical multi-stage channel sand bodies are cut and superimposed with each other,and the interlayer is extremely developed,resulting in strong heterogeneity within the reservoir,resulting in uneven water cut rising law of single well and increasingly prominent production contradictions,which seriously restricts the accurate tapping of remaining oil.Therefore,it is urgent to carry out fine research work on interlayers,clarify the causes and spatial distribution of interlayers,and provide reference for the study of remaining oil distribution in fan delta front reservoirs and the precise tapping of remaining oil and enhanced oil recovery.In this paper,the Z oil group of oilfield B in Pearl River Mouth Basin is taken as an example.Based on the data of core,logging,seismic and experimental analysis,the fine stratigraphic division and correlation of the target layer are carried out.The types of sedimentary system and sedimentary microfacies are sorted out.The type of configuration unit,the superposition connection relationship of configuration elements and the quantitative scale of fan delta front are studied.The three-dimensional geological model of interlayer is established,and the spatial distribution law of interlayer is clarified.Finally,the influence of interlayer distribution on remaining oil is analyzed.The research shows that the Z oil group of oilfield B in the study area belongs to the fan delta front deposition,which mainly develops underwater distributary channel,mouth bar,underwater distributary channel and front sheet sand sedimentary microfacies.The sand bodies are the most developed in the period of Z-2 sand group and Z-3 sand group.In the vertical direction,the multi-stage channel sand bodies are cut and superimposed each other,and the sand body range in the period of Z-1 sand group is gradually reduced.Through the observation and analysis of coring wells and previous research results,the interlayer in the study area are divided into two types: argillaceous interlayer and physical interlayer.The logging identification standards of the interlayer are summarized,and the causes of different types of interlayers are analyzed.Based on the PETREL geological modeling software,the three-dimensional geological model of the interlayer in the study area was established on the basis of the previous research by the method of phasecontrolled modeling,and the spatial distribution characteristics of the interlayer were described.Combined with the numerical simulation prediction results,it is considered that the remaining oil in the Z oil group of the oilfield B in the study area is mainly concentrated in the eastern part near the fault,and is distributed in a strip on the plane,and is controlled by the distribution of the interlayer in the longitudinal direction,which is characterized by ’eave-oil’ and ’roof-oil’. |
