Abstract: The siltstone reservoir has many vertical small layers. Well productivity is affected by sand blocking. Based on the existing productivity model of inclined vertical well, the permeability of screen pipe, annulus filling layer, squeeze filling layer and reservoir are described in detail, and the formula of skin coefficient of mechanical sand control is improved. The blocking law of sand control system is analyzed through laboratory experiments. It is considered that with the increase of displacement volume number and displacement flow, the plugging of sand control system intensifies and the maximum permeability decreases by 40%. Reservoir particles enter the casing and block the annulus gravel and sand control screen, resulting in a sharp increase in skin factor and a decrease in production capacity of more than 80%. Expanding the squeeze packing radius can block particles away from the wellbore and help to maintain oil well productivity. Through the optimization analysis of the filling radius of layered sand control wells, it is found that expanding the filling radius in medium and low permeability can improve the interlayer production effect. The filling parameters of sand control wells in typical blocks are optimized, and the filling radius of S4 layer with low permeability is expanded. With the measures, the oil well fluid volume remains stable, and the daily oil production increases by 9.56 t.

Key words: fine siltstone reservoir, blockage rules, productivity analy, layered sand control, optimized filling radius, interlayer contradiction