The Diagenesis Study Of Weizhou Formation In X Oil Field In We's Weizhou Sag And The Control Of Reservoir Physical Properties

In order to study the diagenesis and evolution characteristics of X oil field in WE's Weizhou sag,It can guide the exploration and development of X oil field and even the Beibuwan Basin in the future.Based on the data of fluid inclusion temperature,vitrinite reflectance,sporopollen color,mudstone pyrolysis,mass spectrometry and chromatograph,X-diffraction,electron scan microscopy,electron probe,thin sheet and cast sheet under microscope,the petrographic characteristics of clastic rocks and diagenesis of various sand and mudstone are studied and the diagenesis stages are divided.The reservoir physical characteristics and main diagenesis influencing factors of X oil field in WE's Weizhou Sag are studied systematically.The results show that:W?reservoir is rich in lithic quartz sandstone,which contains polycrystalline quartz.The polycrystalline quartz has strong rigidity and anti-compaction ability,which can protect the pores formed in the reservoir.In this paper,the current diagenetic stage division of China's oil and gas industry is refined,subdividing the A stage of the intermediate diagenetic stage into four micro-periods of A₁¹?A₁²?A₂¹and A₂²,which is helpful to study the effect of diagenesis on reservoir physical properties in more detail.The physical properties of the W?reservoir in X oilfield are good,and the medium-porosity and ultra-high permeability reservoirs are developed in the micro-period A₁²the intermediate diagenetic stage.