A system and a method for controlling the flow of fluid in a branched well from a reservoir (29), the system including a completed main well (27) having at least one uncompleted branch well (25), an annulus (24) defined between the reservoir (29) and a production pipe (1) of the completed main well (27) and at least two successive swell packers or constrictors (26) defining at least one longitudinal section of the main well (27) and within which at least one branch well (25) is arranged, and including at least one autonomous valve (2) arranged in the longitudinal section of the main well (27) defined between the two successive swell packers or constrictors (26). The uncompleted branch wells (25) are provided to increase the drainage area, i.e., maximum reservoir contact (MRC).