Study On Reservoir Characteristics And Diagenesis Of Liuyiduan Of Huachang-Bailian Regain In Beibuwan Basin

Beibu Gulf Basin is an important petroleum-bearing basin and petroleum production base in China.its total oil and gas resources are huge.Developed in the middle-eastern part of the Fushan Sag in the Beibu Gulf,the Bailian Sub-Concave has made its reservoir characteristics diversify due to its complex and changeable structural pattern.In order to provide a reliable basis for the potential of oil and gas deep excavation in this area,this paper studies the relevant reservoir characteristics and diagenesis in this area.While How to effectively evaluate these reservoirs and provide basis for drilling oil has become a difficult problem to overcome.On the basis of referring a large number of related documents and collecting project data as well as studying the microscopic characteristics of reservoirs and analyze their correlation,we studied the characteristics of reservoir diagenesis and divided the diagenetic stage.Liuyiduan reservoir lithology is mainly composed of feldspathic lithic sandstone and lithic sandstone which have a high degree of structural maturity and low compositional maturity.The small amount of lithic quartz sandstone has highly resistant to compaction and has good “hole protection”.effect.The particle size of the reservoir detrital granules is mainly fine-medium sand and poor-medium sort,roundness-degree is sub-edge-secondary and sub-circular,and the thickness of the reservoir is mainly medium-thick.The pores are dominated by secondary pores,accounting for more than 95%.The reservoir sandstone has the pore structure of "mesopore-fine throat-thin throat-more uniform throat-uneven throat-ultra-low-permeation to infiltration".The total content of interstitial materials is3.6%~13.2%.The type of interstitial material is mainly argillaceous and carbonate minerals.The area belongs to the middle-high temperature gradient region.The types of formation pressure are mostly atmospheric pressure,and few wells develop abnormally low pressure and overpressure.The degree of thermal evolution of organic matter is relatively low,Ro is generally less than 1.0%,and the maximum is 1.43%.The diagenesis of clastic rocks of the Huachang area of the Fushan depression is divided into four stages(sub-periods): the early diagenesis of A and B stage as well as the A1 stage and A2 stage in middle diagenesis stage.The reservoir properties are mainly affected by many factors such as the original composition of the sediment,diagenesis,sedimentation and tectonism.The evaluation of reservoirs is the core research in the development of oil and gas and an indispensable part of research.On this basis,the reservoir formation mechanism and diagenetic evolution model were established,and the diagenetic facies were divided.Study the vertical and horizontal distribution discipline and its relationship with reservoir properties which The purpose is to lay a scientific foundation for predicting a powerful reservoir block on the basis of the understanding of the controlling factors of reservoir development.