The High Speed Flow Mechanism And Production Prediction Of Volatile Oil Reservoirs In West Africa

Deep water volatile oil reservoirs always maintain the formation pressure during its production.West Africa volatile oil reservoir is a high production reservoir,its percolation characteristic is different from the normal reservoir,and seepage velocity near the well hole is high.The high speed Non-Darcy flow as well as the water production,degassing,sand production and the different well completion methods make the normal productivity formula difficult to forecast the well production.This paper conducts single phase water,single phase oil and oil in bond water as well as oil and gas Non-Darcy flow experiment,conclude single phase and two phase Non-Darcy flow characteristic.And establish the relationship between Non-Darcy coefficient and the permeability,and establish Non-Darcy flow equation.Conclude the oil and gas non-Darcy flow mechanism.Meanwhile,evaluate the influence of the high speed non-Darcy flow and the well completion method,establish the single well prediction production equation which considers the water production,degassing,high speed Non-Darcy flow and sand production.The research shows that critical velocity is lower in the low permeability rock,the influence of the Non-Darcy is higher in lower permeability reservoir,bond water decreases the oil critical velocity,Non-Darcy coefficient increases as the permeability decreases,and gas phase decreases the oil critical velocity in two phase flow.Well production prediction equation,which considers the well water production,degassing,high speed Non-Darcy,sand production is more accurate than the normal production prediction equation,productivity prediction precision can increase 88% by using the new equation.