In long horizontal wells, early water or gas may breakthrough into the wellbore due to imbalanced production profile caused by heel-toe effect, reservoir heterogeneity or fracture existing. Once coning occurs, oil production may be severely decreased due to limited flow contribution from the other regions. Inflow control devices (ICD) are usually installed to maintain the flow across production zones uniformly by creating an additional ICD pressure differential which cancels out the imbalanced production profile. This will lower startup production, however, unwanted fluids from breaking through are significant delayed, and total oil production is maximized. Unfortunately, once low viscosity fluid (water/gas) does break through, they will take over the well, significantly reducing oil production.

In this paper, a novel autonomous inflow control device (AICD) design is proposed based on the combination of nozzle-based ICD and water swelling rubber (WSR). The WSR installed in the nozzle swells once water breakthrough occurs, and the swell increment will be adjusted automatically according to water content, thus changing the minimum flow area and flow resistance rating (FRR) of the device. This autonomous function enables the well to continue producing oil for a longer time while limiting water. To highlight the excellent performance of the novel design, three other designs (nozzle-based, helical channel, and tube-type) with a same FRR of 0.8 were compared, with fluid property sensitivity, and structural parameter optimization researched. The results show that the device has a good performance for both oil producing and water restricting, which enables the well to continue producing oil for a longer time, and maximizing the total production.

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