Study On The Law Of Water Drive Development Index Based On Relative Permeability Of Thin And Poor Layers In Xing 6 Area

Xing 6 Area is located in the southeast of Xingbei Development Zone in Daqing Oilfield.After more than 50 years of exploration and development,it has entered the stage of high water cut and ultra-high water cut.The remaining oil in the reservoir is scattered,and it is difficult to increase production.In order to ensure the stable production of the oilfield,the object of water drive development is gradually transformed into thin and poor reservoir.The geological condition of thin and poor reservoir is complex,the development benefit is poor,and the development law of water drive is quite different from that of high permeability reservoir.Therefore,it is necessary to study the variation law of relative permeability curve in different development stages of thin and poor reservoirs,determine the characteristics of composite relative permeability curve of thin and poor reservoirs,establish the development index prediction method based on composite relative permeability curve of thin and poor reservoirs,reveal the water drive development law of thin and poor reservoirs,and provide the basis for the formulation of development planning.According to the actual relative permeability curve of Xing 6 Area,combined with the core micro pore structure parameter data provided by the field,this paper describes the relative permeability curve characteristics of thin and poor reservoirs in different permeability levels and different development stages,clarifies the influence of micro pore structure parameters on the relative permeability curve,and establishes the composite relative permeability method and the prediction method of relative permeability curve at different water cut stages,the main development index calculation method is established,and the production and water cut change law and its influencing factors are analyzed.Combined with the storage and production balance of different blocks and different well patterns in Xingbei Development Zone,the development adjustment countermeasures are formulated.The results show that: with the decrease of permeability,the relative permeability curve changes from concave to straight;the average pore throat radius has the greatest influence on the characteristic parameters of relative permeability;the composite permeability curve of thin and poor reservoir has the characteristics of high irreducible water saturation,large saturation of isopermeability point and narrow span of two-phase flow;compared with Arps method,the calculation accuracy of oil production prediction model based on composite permeability is improved by 1.65%;compared with the water drive law curve method,the calculation accuracy of the water cut prediction model based on composite permeability is improved by 1.79%;at present,the reserve-production ratio of Xing 4-6 line water flooding secondary well pattern and tertiary well pattern is low,the reserve-production ratio of the secondary well pattern of Xing1-3 line water flooding,Xing one injection and one exploitation,Xing 4-6 Area and Xingbei East transition zone is higher;according to the development effect of different well patterns in Xingbei Development Zone,the main development adjustment measures are determined as follows: prevention and treatment of casing damage wells,treatment of low pressure area,strengthening subdivision water injection and fracturing and acidizing of oil and water wells.