Study On The Law Of Water Intrusion In Fracture-porosity Reservoir

In the development of fractures,active water bodies,and water intrusion in fracture-porosity reservoirs,in smaller pore throats,under the action of strong capillary forces,fluids are prone to osmotic action,resulting in actual development of water-sealed gas.It has a great influence on production,so it is necessary to carry out in-depth understanding of the theoretical techniques and achievements related to water intrusion law,and carry out experimental theoretical research on the permeability and influencing factors of fracture-porosity reservoirs,and carry out crack-pore type.Microscopic numerical simulation of reservoir seepage mechanism;further establishment of numerical simulation of macroscopic water intrusion considering the effects of seepage and large-scale cracks,analysis of factors such as gas production rate,well placement,gas well opening and other factors affecting fracture-porosity reservoirs The development impact of this study,the following results are recognized:(1)Using nuclear magnetic resonance technology to determine the pore size distribution of the core,through the MRI nuclear magnetic imaging technology,you use the visualized infiltration experimental device to study the distribution and migration of formation water in the core.The results show that in the initial stage of infiltration,small pores are first filled quickly by water,and then the medium pore water content is gradually increased.The increase of macroporous water content leads to an increase in water saturation and a significant decrease in core permeability,which is the main reason for the decrease in permeability.(2)A set of experimental methods for unsteady seepage evaluation was established.The results show that the fracture permeability and matrix permeability decrease greatly,and the fracture permeability decreases between 70 and 80%.The matrix permeability The decline is between 60% and 70%;(3)Using finite element software to establish a mathematical model of microscopic pore-throat gas-water infiltration simulation,and analyze the gas flow characteristics during the water saturation process of crack wall.The results show that the small pore throat connected by the crack is wetted by the formation water,and the osmotic effect is obvious.At the same time,a large amount of water-sealed gas is formed,which reduces the final mining effect of the gas reservoir;(4)On the basis of the numerical simulator,analyze the influence of water phase to matrix wave characteristics during water intrusion and evaluate the influence of water intrusion on matrix storage.The results show that the bottom water is more likely to break along the crack under the large production pressure difference.The closer the vertical well position is to the crack location,the easier the bottom water is along the crack.When the degree of opening exceeds a certain value,the straight well is more likely to invade the water;the high inclination crack is also easy.Cause the bottom water to invade.