Experimental Analysis and Research on Selective Water Control of Capillary Fluid in Tight Gas Reservoirs
Taking the dense sandstone core in Linxing area as the research object,a potential suitable type of stable gas and water control capillary fluid system was optimized through orthogonal experiments.The quantitative relationship between system performance parameters,construction process parameters,and stable gas and water control effect was established.The system formula was optimized based on the evaluation criteria of stable gas and water control effect.According to the characteristics of Tight gas formation,combined with the mechanism of Fuzzy-ball Fluid stabilizing gas and controlling water,the breakthrough pressure gradient parameter is introduced to evaluate the change of formation gas and liquid two-phase flow capacity before and after the plugging of cashmere fluid.The experimental results indicate that there are differences in the degree of change in total porosity,effective porosity,and movable porosity of cashmere fluid,which is related to the performance of Fuzzy-ball Fluid under different formulations.The range of changes in total porosity,effective porosity,and movable porosity is 40.53%～59.63%,35.42%～44.81%,and 55.08%～64.75%,respectively.According to the strength of the system's stable air and water control,three types of capillary stable air and water flow systems were optimized,and the optimized capillary stable air and water control fluid system achieved a water control rate of over 70%.At the same time,after injecting three types of strength capillary stable gas and water control systems into the formation,the gas phase breakthrough pressure gradient was controlled to increase by 12.50%～22.22%,and the water phase breakthrough pressure gradient increased by 77.76%～79.01%.The optimized capillary fluid system has the characteristics of significantly reducing water production and maintaining gas production capacity with small disturbance,which can achieve the effect of stable gas and water control.
tight gasstable gas and water controlvelvet fluidorthogonal experimentoptimization
NETL
NSTL
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