Experimental Study On Improving Imbibition Recovery Of Tight Reservoir By Composite Fracturing Fluid System

In recent years,with the development and improvement of fracturing fluid technology,guar gum,synthetic polymers,surfactants and other fracturing fluid technology is basically mature,and in the case of specific reservoir needs to be applied.Fracturing fluid main technology diversification of the adaptability of the dense reservoir and the realization of recycling is the next period of time to meet the technical requirements of fracturing fluid and control costs of the decisive factors to meet the low damage,low cost,efficient environmental protection and other technical indicators are still The future development of fracturing fluid,and put forward new ideas on the technical conditions of composite fracturing fluid;put forward new ideas for compound fracturing fluid technology;through the experimental study and constantly improve the performance of surfactant and new fracturing fluid.Through the performance evaluation of surfactants and composite fracturing fluid system,the composite fracturing fluid system which can improve the recovery rate of dense reservoirs is screened and the reservoir adaptability is analyzed.mechanism and main Influencing factors of enhanced oil recovery by compound pressure solution incompact reservoir.Hydrophilic core saturated oil process there is a threshold pressure,can spontaneous seepage drive oil;lipophilic core,the oil phase can be self-absorption,saturation process does not exist threshold pressure;lipophilic core,in the surfactant solution spontaneous infiltration The effect of wetting and non-wet pressure on the wetting phase is gradually decreased,and the capillary force gradually decreases And gravity balance;capillary force caused by oil and water seepage can be divided into three parts: changes in water saturation caused by seepage,permeability changes caused by changes in seepage and wetting caused by seepage;reverse seepage favorable conditions are hydrophilic,low permeability.The spontaneous seepage and expulsion is an important oil recovery mechanism for fractured reservoirs.The mechanism of oil and water displacement between the rock mass is studied systematically.The mechanism of the oil and water displacement between the matrix rock blocks is evaluated by the evaluation of the surfactant Improve the role of the method to improve the infiltration of dense reservoirs and technology to form a rational understanding of the role of capillary seepage based on the development of reservoirs to provide the basis.To improve the permeability of dense reservoirs should not blindly pursue the ultra-low interfacial tension for the purpose of reducing the interfacial tension on the matrix rock seepage oil drive has a two-sided impact.