Feasibility Of Hydraulic Fracturing For Liu-1 Formation In Weizhou 11-4N Oilfield

So as to improve low permeability oilfields’developing effects,reservoir fracturing technology is often adopted.According to reservoir properties and stress of layer L1 in Weizhou 11-4N oilfield,combining with the advantages and disadvantages of fracturing technology between horizontal and directional wells,the feasibility analysis on fracturing stimulation is carried out.This study is of great significance to efficient development of low-permeability reservoir.On the basis of reservoir properties and characteristics’analysis during the second stage of Weizhou 11-4N oilfield ODP,rock mechanics and formation stress experiments are used to establish the correlative model of dynamic and static elastic parameters in layer L1.The geostress gradients are obtained in vertical,maximum and minimum horizontal direction.Wells’rock mechanics and geostress profile can be established through experiment and logging parameters,and the maximum horizontal geostress direction,i.e.N125 E-N130E,is determined by imaging logging and formation dip logging.The past result proves that the horizontal water injection wells in Weizhou 11-4N oilfield should not be fractured.In order to meet the 1:1 injection requirement after fracturing,it is suggested that the water injection wells should be injected with formation fracturing pressure.Through qualitative optimization,5 wells to fracture are initially screened out and sorted.Fzzy mathematics method,reservoir engineering method and numerical simulation method are used to evaluate the daily oil production index after fracturing,two wells(well B11H and well B15)are recommended for fracturing.The results show that the second stage of Weizhou 11-4N oilfield has a certain fracturing potential.The cumulative oil rate of two wells after fracturing in the first three years increases by 102000m~3,the oil recovery rate rises to 3.96%,the cumulative oil rate will increase by 11000m~3 in 20 years,and fracturing effect is obvious,which brings about surprising fracturing effects...