Researching On The Distribution Of Reservoir Sand Body Of The 3-4 Section Of The 72 Block Of Gudao Oilfield

The upper section of the Guantao formation in the Gudao oilfield is the main stratigraphic layers containing oil and gas,which has huge exploitation potential.According to the previous regional geological research,it can be determined that the 3-4 section of the upper section of Guantao formation is meandering river sedimentary facies.Due to the factors such as the rapidly changing of sedimentary facies,fluvial facies reservoir become complex,sand body longitudinal and horizontal distribution are unstable.Figuring out the problem of the spatial distribution of fluvial facies reservoir sand body is conducive to the improvement of oilfield development potential and also convenient for the exploration and development of oilfield.Therefore,studing the regularities of distribution of sand bodies in the target layer is necessary,which prepares for the oil deposit description of reservoir geological modeling,and is sufficiently significant.Using geological and well logging data to divide single well sedimentary microfacies and stratigraphic unit,and establish the isochronous stratigraphic framework;study on the distribution law of sand body plane and the distribution pattern of sedimentary microfacies in meandering river,describe the microstructure morphology of the top surface of sand body;focus research on geometry forms and distribution regularities of the main reservoir sand body,and establish three-dimensional geological model.Divide the target layer into two sand groups,nine small layers,then the results show that the stratigraphic distribution is relatively stable and the stratum is relatively flat;reservoir sand body in this research area is consist of river course,natural levee,crevasse splay,river floodplain microfacies,among that riverbed facies is the main sand body;the distribution of sand body is affected by microfacies and paleo geomorphology,it has strong directivity,and vertically and horizontally changes a lot,but the main sand body distribute steadily;the establishment of fine geological model has made a prediction on the favorable areas,and laid the foundation for numerical simulation.