Experimental Simulation And Optimization Of Water Huff-puff In A Tight Sandstone Reservoir

Currently,the tight reservoir has become the focus of the world oil and gas exploration and development.The fractures formed by volume fracturing have an important influence for the exploitation of tight reservoirs.Conventional water flooding is a common development method which usually causes water's break through and has a low recovery level.But water huff-puff can use fractures for imbibition,replacing oil from small channels to large channels and fractures.Therefore,it is important to research the water huff-puff development efforts and sensitivity factors of tight sandstone reservoirs.This paper had carried out experiments to study the influence of fractures on water flooding and water huff-puff before and after fracturing and choose the appropriate development method for a tight sandstone reservoir.Then a series of experiments had conducted to test different influences of temperature,wettability,permeability,pressure,injection speed and soak time on the oil recovery of water huff-puff.Subsequently,a theoretical model of water huff-puff had built to conduct sensitivities analysis for water volume in one injection cycle,injection speed,soak time and production rate which were chose by the injection-production parameters research status at home and abroad and the actual experiences,the optimization parameters were also chose for this model by orthogonal optimal design.At last,the optimization parameters were used to perform four cycles of water huff-puff and the result had validated the development effect of it.The research results of this paper provide experimental and theoretical basis for the development of tight sandstone reservoir and have some reference for other development methods which also use capillary imbibition to produce oil.