Abstract: A flow arrangement (10, 12) for use in a well through one or more underground reservoirs, and where the arrangement (10, 12) is designed to throttle radially inflowing reservoir fluids produced through an inflow portion of the production tubing in the well, the production tubing in and along this inflow portion being provided with one or more arrangements (10, 12). Such an arrangement (10, 12) is designed to effect a relatively stable and predictable fluid pressure drop at any stable fluid flow rate in the course of the production period of the well, and where said fluid pressure drop will exhibit the smallest possible degree of susceptibility to influence by differences in the viscosity and/or any changes in the viscosity of the inflowing reservoir fluids during the production period.