The Prediction On The Remaining Oil Distribution Of Ng5²⁺³ Unit In The West Part Of The 7^th Block In Gudong Oilfield

Ng5²⁺³ unit in the west part of the 7th Block in Gudong Oilfield belongs to sandstone reservoir of fluvial facies.It has already been developed for more than 30years until March 2015.Average single well's water content ratio has reached up to98.4%and is in the stage of extra-high water containing.Through high producing degree of reservoir,high water containing of production wells,complexity and high fragment of remaining oil distribution and unclear understanding of affecting factors of remaining oil and so on,it increases difficulty in exploiting the remaining oil and enhancing oil recovery.Based on the analysis of reservoir dynamic and static data,the first step is to do the development dynamic analysis,including the development stage division,development status research,the laws of development analysis,the evaluation of development effect and recovery ratio prediction,and have a detailed understanding of the production and development history.By the means of reservoir numerical simulation,it focuses on the study of the angle of reservoir architecture controlling the remaining oil,reveals the distribution of remaining oil in the plane and vertical in study area at March 2015,clarifies how reservoir architecture controls the formation and distribution of remaining oil,summaries laws and main control factors of remaining oil distribution and then puts forward the targeted technical measures for guiding the next step of development and adjustment for realizing efficient development of reservoir.According to geological research,reservoir engineering analysis and the result of reservoir numerical simulation,the study suggests that the natural energy of the reservoir in study area is sufficient.Early development shows that average single well production is high without water.Well group 4 has the best development effect and the highest recovery degree,which has a further potential for development.It highlights how the plane permeability,horizontal rhythm,reservoir architecture,well type and technical measures control remaining oil distribution.Influenced by intraformational interbeds,the remaining oil is enriched in upper layer.In the retention area which well spacing is large and is controlled by reservoir architecture,the remaining oil is enriched.