Research On Classification And Treatment Measures Of Gaotaizi High Water Cut Well In Western Central Area

West Gaotai in the central area was put into operation in 1979.After the implementation of encrypt adjustment in 2009,the well distance has reached 106m.As of December 2019,the comprehensive water cut of the whole area has reached 97.7%,The water content of 40%oil wells reaches over 98%,and the whole block has entered the ultra-high water cut period.Therefore,it is urgent to sort out a complete set of classification methods and treatment measures for high water cut Wells to achieve the purpose of effective water control and efficiency improvement.Based on the above problems,on the basis of block geological modeling and numerical simulation history fitting,this paper proposes a method to calculate the critical water saturation by using the combination of ten standard relative permeability and flow separation equations in Daqing.The curve obtained by data fitting can calculate the critical water saturation under different permeability,and compared with the current water saturation,and then judge the degree of flooding in one oil-water area.The high water cut oil wells are classified according to the degree of flooding.The high water cut oil wells are divided into layer upon layer of high water cut,multi direction high water cut and single direction high water cut oil wells.The sedimentary environment and production characteristics of different types of high water-cut wells are studied from two aspects of static geological factors and dynamic production characteristics.At the same time,the plane and vertical heterogeneous ideal models are established to study the displacement characteristics of oil reservoirs in high water cut period.According to the numerical simulation results,the relationship between the sweep condition in high water cut period and the grid recovery degree and the displacement multiple is given.Potential tapping of different types of wells can be evaluated by residual oil analysis and water flooded degree,and corresponding control measures are put forward.The theoretical analysis of shut-in measures is carried out in homogeneous and heterogeneous multi-layer models to study the shut-in and oil increase mechanism of high water-cut wells.During the four-year period of block measures,for the layer the oil wells of upon layer of high water cut,the hole filling measures after shut-in are adopted,and the oil production is increased by 69.18×10~4 m~3.For the oil wells of multi direction high water cut,water plugging of oil wells and profile control of water wells are used to effectively reduce the liquid683.12×10~4m~3 and reduce the water cut by 0.59 percentage points.For the oil wells of single direction high water cut,the wells with water cut of 98%were treated by fracturing low permeability layers,which effectively improved the reservoir physical properties.The cumulative oil increment was 21.82×10~4m~3,and the water cut was effectively reduced by 0.63percentage points.