Study On Sand Body Connectivity Of S? Formation Of The Middle West-2 Area In South Block Of Lamadian Oilfield

The sand bodies of different periods and different scales of the SIII Formatoin of the Middle West-2 Area in South Block of Lamadian Oilfield are interlaced and stacked,and the distribution of sand bodies and the connection between sand bodies are complicated.After years of water injection development,the oilfield has now entered a period of high water cut.Due to the unclear understanding of the connectivity of sand bodies,the difficulty of mining is increasing.Exploring the connectivity of sand bodies has become an important part of tapping potential oil and improving development results.In this paper,the delta front sand body of the SIII4-7 sand group is taken as the research object,and the sand body connectivity research is carried out.First,using the core and logging data,the stratigraphic division of the target interval is carried out.On this basis,according to the vertical staging of the sand body and the lateral demarcation mark,the identification and division of the single sand body is carried out.Secondly,the sand body is finely characterized,the distribution characteristics of the sand body on the section and the plane are clarified,and the overlapping and contact patterns of the sand body in the vertical and lateral directions are summarized.Then,the sand body connectivity is studied from the lateral,longitudinal and internal aspects.Based on the injection-production data and the inter-well flooding,the lateral contact pattern of the sand body and the sand body connectivity probability model are used to characterize the lateral connectivity of the target layer.The longitudinal connectivity is determined according to the vertical stacking pattern of the sand body and the interlayer interlayer distribution characteristics;the internal connectivity is analyzed by using the in-layer permeability heterogeneity parameter and the interlayer parameters.The relationship between sand body connectivity and remaining oil enrichment is summarized to provide a basis for clarifying the remaining oil distribution.In this paper,the target layer is divided into single sand level,and the sedimentation period is divided by the argillaceous,calcareous and physical interlayers in the vertical direction,and the single sand is identified in the lateral direction by the discontinuous inter-channel deposition and the top surface elevation difference of the sand body.Body boundary.There are four kinds of lateral contact patterns and four vertical contact patterns in the target layer.The vertical overlapping relationship of the sand bodies is mostly vertical separation and cutting,and the lateral contact relationship is mostly docking and cutting..The lateral connectivity is related to the lateral contact pattern of sand bodies,the degree of sand body cutting and the type of sedimentary microfacies;the longitudinal connectivity is related to the vertical overlapping pattern of sand bodies under the control of interlayer interlayer;internal connectivity and unevenness within the layer The degree of plastiness is related to the development of interlayers in sand bodies.According to comprehensive analysis,the sand body connectivity of SIII4+5 layer is relatively poor,while the SIII6+7 layer sand body connectivity is relatively good.There is a certain relationship between the accumulation of remaining oil and the connectivity of the sand body.The remaining oil is greatly affected by the sand body stacking pattern,the interlayer distribution characteristics,the sedimentary microfacies and the internal rhythm pattern of the sand body,usually at the height of the sand body.The parts,the interlayer sealing,the top of the sand body,the side flaps gather,or gather inside the sand body with poor connectivity.