Abstract:

In view of the issue on the low permeable and low abundance reservoirs being difficult to develop,the deliverability calculation model of different well pattern under the condition of non-Darcy flow law is used to the optimal design of well pattern in low permeable reservoirs.The producing index is taken as the indicator evaluating the producing degree of low permeable reservoir and to provide reference for optimal well pattern design.A certain low permeable reservoir is taken as example,combining with threshold pressure gradient,the relationship among the well pattern,the pressure different between production and injection,deliverability and producing coefficient.Results show because of the existence of threshold pressure gradient in low permeable reservoir,the greater the well spacing is,the more the pressure depleted in overcoming threshold pressure is required and smaller the producing coefficient is.In that reservoir,effective flooding system can not be established under the current condition of 300m well spacing,so the spacing should be shortened.

Key words: low permeability reservoir, non-Darcy flow law, well spacing, threshold pressure gradient, pressure difference between production and injecti