Particle filling based ICD isostatic water control technology used for horizontal wells in limestone reef oilfields

As the development goes, some wells suffer water flooding in limestone reef reservoirs. And in order to improve the quality of water control, the particle filling based ICD isostatic water control technology is developed. In this paper, the structure and working principle of this kind of water control string were introduced. Then, the aperture and installation density of flow limiting valve, the size of filling particle and the filling operation parameters (pump in pressure, pump in flow rate and sand proportion) were calculated and designed. Finally, fresh water injection experiment and field application case of Well X5 were described. The field application shows that two new wells have cumulative oil increment over 2.5×10⁴ m³, and their water cut is 62% lower than that of their neighboring wells. The isostatic water control can be realized to the uttermost while guaranteeing the productivity of oil wells by analyzing comprehensively the relationships between the dimension and the installation density of flow limiting valve, between the size of filling particle and the size of formation sand, and between the filling pressure and the fracturing pressure. In conclusion, this technology is suitable for the water control of horizontal wells in the reservoirs with strong heterogeneity or developed fractures. It is recommended to install flow limiting valves uniformly in horizontal sections. The research results can provide the basis for the design of water control scheme of the reservoirs with strong heterogeneity or developed fractures.