The Reservoir Comprehensive Evaluation Of Fuyu Oil Layer In Aobaota And Putaohua Area Of Daqing Oilfield

The Songliao Basin is one of the largest petroliferous basins in China.Daqing placanticline is located in the northern part of the Songliao Basin.It is a secondary tectonic unit in the central depression and the most important middle oil accumulation system in the Songliao Basin.In the Daqing placanticline,Putaohua and Aobaota are two third tectonic units;Fuyu Oil Layer have access to industrial oil flow,with high development potential.The influencing factors of the Fuyu reservoir mainly include sedimentary facies,reservoir characteristics,regional structures,etc.So it is necessary to research them for guiding oil and gas exploration and development.Fuyu Oil Layer was divided into FⅠand FⅡ,and established some longitudinal and transversal stratigraphic correlation sections,so completed the division and contrast of formation in the region,and draw the top structure map according hierarchical data.Delta front subfacies and delta plain facies are mainly developed in Fuyu Oil Layer in the research area,and shallow lake subfacies are developed locally.Delta front subfacies mainly include subaqueous distributary channel,frontal sheet sand,and subsea interdistributary bay.Delta plain facies mainly include distributary channel,natural levee,crevasse splay and interdistributary bay.The sand body in the delta plain facies is the most important oil-bearing reservoir.The reservoir physical properties of the Fuyu Oil Layer is low-porosity,low-permeability and extra-low-permeability.The types of main sandstone is feldspar lithic sandstone,secondly is lithic feldspar sandstone.The compositional maturity is Low but textural maturity is high.Combining the standard of reservoir classification,subaqueous distributary channel and distributary channel belong to class Ⅰand class Ⅱ reservoir,and interchannel class Ⅲ reservoir.As a whole,the reservoir physical property of FⅠis better than FⅡ.The main diagenetic effects include compaction,cementation,dissolution and denudation.Study shows that compaction and cementation can play a destructive role in reservoir physical property,while dissolution can play a constructive role in that.Based on the above analysis,favorable exploration zone in Fuyu Oil Layer were forcasted and provided a favorable basis for further exp loration and development.The class Ⅰreservoir in Putaohua area are more than in Aobaota area.The classⅡreservoir distribute both Putaohua and Aobaota area.