Study On Water Injection Interval Division And Allocation Method Of The Gao Taizi Reservoir In The Western Part Of Central Ice By Wang Xin

The main oil layers in Daqing oilfield basically enter the period of ultra high water cut,collective presentation,high water cut,low oil recovery,complex distribution of residual oil,low efficiency and ineffective circulation of water injection,layer division developme nt difficulty and so on.In view of the current development characteristics of the high platform in the west of Daqing,the water injection layer is the main object of study.According to the distribution law of the remaining oil and the status of the section division,the dynamic analys is of the water injection well is carried out and the corresponding comprehensive adjustment is made.According to the three static criteria of small layer number,permeability variatio n coefficient and sandstone thickness,the adaptability of the existing layer divisio n method is evaluated,and the new subdivision interval adjustment boundary is given in combination with the dynamic parameters of the variation coefficient of water injection intensity.On the basis of multidisciplinary achievements,such as reservoir numerical simulation results,the water injection layer is raised and controlled,and the water cut boundary and pressure limit of the lifting control are given.The reasonable value of pressure recovery rate is given,and the reasonable control water amount under different conditions is calculated to form the chart of water control.It is concluded that the control property of the water injection well is affected by the surrounding connection,the water cut in the surrounding production well and the formatio n pressure,and the control property of the water injection well and the 7 kinds of adjustment countermeasures are determined.When the bottom hole pressure is fixed,the formatio n pressure is best in the range of 8.7MPa~10.67 MPa and the yield is the highes t,and the water content is in the range of 80%~90%.The layer division standard is that the layer section is 94.7%,the layer number is less than 7,the layer is less than 7,the layer of the sandstone is less than 8m,and the thickness less than 8m is 94.2%;the variation coefficient of the water absorption strength of the layer is <0.9,and the variation coefficient of the layer water absorption strength of the layer is <0.9.The velocity of formation pressure recovery should not be recovered from the angle of controlling the water cut.More than 0.3MPa/a;through the unit thickness water extraction to calculate the single wel 's reasonable water withdrawal,it is concluded that there are 67 wells in the whole area,and 101 layers need to adjust the water injection volume.After the adjustment of water injection volume,it was predicted that the comprehensive water cut was 97.56% in December 2019 and 0.25% lower than that in the whole area.The daily production oil 617.9t was not adjusted to 21.7t.