Prediction Of The Ordovician Fractured Carbonate Reservoirs In Tarim Basin

Fractured carbonate reservoir prediction has been a difficult issue.It has no satisfactory solution so far,despite years of research.Article select the east Lungu area of Tarim basin as research object to carry out fractured carbonate reservoir prediction.It has been proved that oil&gas accumulation is controlled by faults in the study area.The major pore space include cracks,caverns and holes with the characteristics of burial depth and heterogeneity.It is not easy to predict fractured carbonate reservoir because seismic signal is weak and seismic resolution is lower due to denudation of the top Ordovician.With the exploration and production, it is becoming increasingly difficult to provide more and more favorable area for drilling targets. Therefore, the application of crack identification techniques to predict the development of cracks in the plane of the degree of occurrence, size and connectivity, is important for the next well deployment and improving success rate of drilling.The paper,firstly,study and analysis rock characteristics, sedimentary facies and geophysical response characteristics of the main reservoir space in detail based on the previous research results,and then predict crack distribution,connectivity and favorable zone with geological origin crack prediction method, supplemented by pre-stack AVA attribute analysis and coherent body. Major results as follow:(1) Summed up the east Lungu carbonate reservoir type, geological characteristics and controlling factors based on the reservoir rock, sedimentary facies.(2) Summarize well logging response and built identification mode according to changes the regularity of various well log.(3) Building geologic model to forward seismogram synthesis,and analyzing seismic response and summarizing the identification mode of seismic response,based on the analysis the geologic feature of different reservoir bed.(4) Predict and analysis reservior distribution and connectivity with geologic origin method,AVA and coherent imaging.Get a suit of effective and practical method for Ordovician carbonate rock in the east of Lungu area.The methods in this papers have been applied to some oil and gas fields,the results prove that it is effective and practical.