Certain aspects and features of the present invention are directed to an isolation assembly that can be disposed in a wellbore through a fluid-producing formation. The isolation assembly can include one joint of a tubing section, at least two inflow control devices, and an isolation element. The joint of the tubing section can include at least two ports. Each inflow control device can be coupled to the tubing section at a respective port. The isolation element can be positioned between the inflow control devices. The isolation element can be configured to fluidly isolate the ports from each other.