Precise Depict Of Reservoir Permeability Systems And Prediction Of Fluid Distribution In Gaoshiti-Moxi Area

Longwangmiao formation in middle-sichuan basin acient uplift has been put into attention for a long time,which can basically attributed to its multiple,vast,high quality source rock interlayered with high porosity carbonate and vast,stable acient uplift.Additionnally the prospecting well,GS-1 has discovered the gas layers of Longwangmiao formation in the year 2011,and the fact that multiple prospecting wells had a gas production over a million cubic metre per day.All of these facts established the found of Anyue gas field,which attracted more and more researchers pay attention to the formation in this area.Anyue gas field,located in the east,high level part of middle-sichuan basin acient uplift,is the gas abundant region of this area.The gas contain layers mainly within a nose-shaped-uplift located in Leshan-Longnusi acient uplift.This part of Longwangmiao formation is basically a carbonate platform above a shallow sea shelf.Lithology is dolarenite dolomites,fine-grained dolomite and micritic dolomite.Subphacies are mainly basin phacies and ramp phacies.Microphacies are mainly pellet phacies,interbeach phacies,evaporation lagoon facies and evaporation tidal flat phacies.Vast pellet circling around the Leshan-Longnusi acient uplift,which is the mainly fluid container in this area,and equipped with a good porosity and permeability.In this research,based on tha data provided by South-West China Branch Office of CNPC,we reached following goals:(1)Formed the pattern of sesmic attributes forecast,found the sensitive characterization parameters,via the comparison between the actual data and AVO forward modeling data.(2)Found the parameters of prediction to reservoir permeability systems and the gas abundant region via rock physics analysis and forward modeling.(3)Predicted the distribution of fluid via the AVO fluid discrimination technology and tested the result.The results of this research are as follows:(1)The reservoir layers of reservoir permeability systems are mainly located in upper part of the Longwangmiao formation,as thick as 20 to 65 metres,according to the prediction.The core part of them is around the wells of MX-12,MX-9,MX-13,MX-10,MX-19,MX-8,MX-18,MX-205,MX-11,and MX-202.The thickest part located around the well MX-16,which as thick as over 40 metres in total.(2)The high quality reservoir has a thickness of 10 to 40 metres in total and located around the wells of MX-8,MX19,MX-17,MX204,MX-11,MX-16,and MX-107.The result of prediction has been tested and the result fits well with the well logging data.(3)The gas of research region has a good continuity and a clear boundry betweeen the gas and the water.Gas region mainly located in the region of wells MX-47,MX-13,MX-12,MX-8,MX-17,MX-10,and MX-16.The result has been tested and fits well with actual well logging data.