Establishment Of Horizontal Well Testing Model Of Stress Sensitive Reservoir Considering The Influence Of Bound Water

The characteristics of Sulige gas field are known for low permeability and density,strong stress sensitivity and complex influence of bound water,which bring difficulty in developing.Based on the relationship between the stress sensitivity of the reservoir and bound water saturation,the horizontal well test model considering the influence of bound water is established,and the application analysis is carried out.First,the core samples of the Sulige gas field are selected to carry out stress sensitivity experiments under variable bound water saturation.It is found that the bound water saturation affects the stress sensitivity of the core,the greater the bound water saturation,the stronger the stress sensitivity of the core.The empirical formula of permeability related to the bound water is obtained according to the experimental data.After that,the permeability equation is taken into the horizontal well seepage equation,and the transient percolation function and Laplace transform are applied to deduce the horizontal well flow equation with the upper and lower closed boundary in the horizontal infinite stress sensitive reservoir,then the numerical inverse is carried out and the typical well test curves are compiled by MATLAB.Finally,2 Sulige horizontal wells are taken as examples,the reservoir parameters are retrieved and analyzed by using the well test model.The results show that the horizontal well with large water production is more sensitive to stress sensitivity,and reasonable pressure is suggested for developing.The horizontal well testing model of stress sensitive reservoir under the condition of bound water has a certain guiding significance for reasonable development of tight sandstone gas reservoir.