Study On Productivity Prediction Model For Jinshan Tight Sandstone Gas Reservoir Fracturing Well

The tight sandstone gas reservoir in Jinshan gas field has the characteristics of low porosity,low permeability and low gas saturation.The natural production capacity of gas wells is low,and the industrial airflow must be obtained by fracturing.In the previous 34 fracturing wells,the average sand compliance rate of is 92.7%.On the whole,the success rate of fracturing operations in Jinshan gas field is relatively high,and the difficulty of the operation is relatively small,but the increase production effect of the fracturing is poor.Therefore,the production capacity of Jinshan gas field gas well after fracturing should be studied.In this paper,water sensitivity test,salt sensitivity experiment,alkali sensitivity test,acid sensitivity test,fracturing fluid lock and injury experiment,start pressure gradient experiment,stress sensitive experiment were carried out.The relationship between the starting pressure gradient and permeability were obtained,so does the relationship between the stress sensitive coefficient and permeability.And then the three-dimensional gas and water two-phase mathematical model considering the start pressure gradient,gravity,stress sensitivity and crack failure is established,and the numerical solution method of the model is given.The dynamic fitting and productivity prediction after fracturing are carried out by using Eclipse software.Taking JIN1 well as an example,the influence of permeability,porosity,gas saturation,starting pressure gradient,stress sensitivity,crack length and diversion capacity is analyzed.The research results of this paper have a certain guiding significance for predicting the fracturing production capacity of Jinshan gas field.