Technical Study On Placing Of Well Of Avoiding High-water-cut Producer Layer In Chao 522 Infill Area

Based on well point geologic information of Chao 522 infill area, in this paper it establishes the properties model of permeability, effective thickness, porosity and initial saturation. It adjusts effective thickness and effective node applying sedimentary facies digital returns, which makes digital geologic model match actual oil reservoir comparatively. Considered the effect of dual porosity and dual permeability, the simulation research was done by CMG numerical simulation software, main history macth indexes including geological reserves, total water-cut, single-well water-cut, recovery percent of reserves, pressure. On the basis of meeting the precision history matching required, it analyzes quantitatively the regularities of remaining oil distribution and its influential factor, and studies the effect of oil layer sedimentation characteristics and fracture growing condition on residual oil distribution, and also shows the horizontal and vertical distribution of remaining oil saturation before and after infilling. It make a study of infill well development effect through comparative analysis, expatiates the geofactor and exploitation factor which affect infilling effectiveness. Through analyzing and comparing the effectiveness of every infill readjustment plan, it presents the cause of high-water cut oil layer appeared. Finally it determines the well spacing method of avoiding high-water-cut oil layer. The method is firstly making a fine geologic study, and determines the low limit of adjustable effective thickness of infill well. Then according to the fine study, well spacing is avoided in the area which is under technical criteria. For low permeability fractured oil field, the total guiding ideology of spacing well is that forming line flooding well pattern system along major fracture, determines the condition of sand body expanding and distributing and the direction of fracture growing, lays out infill producer avoiding major fracture direction, then makes a study of numerical simulation. On the ground of numerical modeling data, it analyzes residual oil distribution. For high-water-cut infill well predicted, it should avoid spacing well, while for low-water-cut oil well, it should determine infill or not, combining with dynamic analysis and cumulative injection of connected aged water well. If the cumulative injection is high, it should avoid laying out infill well. It predicts high-water-cut well layer after infilling. On the basis of explaining water-flooded zone with log, combined with sand body sedimentation characteristics and waterflood controlled degree under original well pattern, it determines whether perforate intended zone or not. It should strictly control the size of construction of infill well fracturing, avoid manmade fracture too long, connect natural fracture, and determine the final readjustment plan combined with dynamic analysis.