Mechanism and Characteristics Analysis of Water-Producing Tight Gas Well in Daning-Jixian Block

There is generally no unified gas-water interface in tight sandstone gas reservoirs. The micro-scale reservoir is dominated by gas-water mixed storage. On the macro scale, there are small lens-shaped water bodies or water retention in low parts controlled by structure affected by transverse heterogeneity of sand bodies, which leads to the simultaneous production of gas and water in the whole life cycle of gas Wells and affects the productivity of gas wells in the long run. At present, the average water-gas ratio of Daning-Jixian block is 1.7 m3/10,000 m3, and the impact of water production on gas well productivity is serious and increasing year by year. Based on core water sensitivity, stress sensitivity and nuclear magnetic resonance experiments. This paper evaluated the relationship between reservoir water sensitivity, stress sensitivity and mobile water saturation and gas well water production, and explored the water production mechanism of gas well and the influence of various factors in different production stages. The results show that the water sensitivity is mainly affected by the content of clay minerals, and the higher the content of clay minerals, the greater the initial water production. The higher the stress sensitivity is, the higher the water production will be. The higher the movable water saturation is, the larger the total cycle water production is and the higher the cumulative water production is. By clarifying the mechanism and characteristics of water production, it has significant guiding significance for the formulation of production countermeasures and productivity improvement of water producing gas Wells.