DAN-SQUID®  2-Phase  Steam Distribution System

EN-FAB® Inc. is the exclusive worldwide licensee to market, manufacture and service an innovative Two-Phase Steam Distribution System, developed by Shell Oil Company.

In Thermal Enhanced Oil Recovery (TEOR) projects, high quality two-phase steam is injected into hydrocarbon bearing formations to increase production. If it is necessary to distribute this steam to individual injection wells, the problem arises in dividing the main flow into the individual flows while maintaining the same ratio between vapor and water in the individual flows.

The above problem will be more significant when large co-generation plants are installed. The co-generation plants will produce both electricity and the steam required for the TEOR projects. These plants will be centralized and the initial steam flow will be large and must be divided into the individual flows for various injection wells.

The DAN-SQUID® system has been extensively used at Shell's steam flood operation at the Kern River fields in Bakersfield, California.

In the past, it was assumed that steam quality was equally distributed throughout the steam distribution system and was nearly equal to that of what was discharged at the Steam Generator(s), other than some minor thermal insulation loss. In more recent times, this has been proven to be a false assumption. The splitting of two-phase flow streams is the source of the problem. When branching (splitting) a two-phase flow, the vapor phase and liquid phase have a tendency to split disproportionately except under ideal conditions.

This disproportionate phase splitting becomes increasingly pronounced when the difference in mass rate between the branch splits increases. This effect is reduced by following the “good practice” of arranging piping tee's in the “dead end” configuration but does not eliminate the phenomena. The problem is further exasperated when even minor geographical elevation differences exist between the steam injection wellheads. The wells at lower elevation invariably receive a disproportionately higher content of the liquid phase as compared to the steam injectors at higher elevation which receive a greater component of the vapor phase. The problem can be minimized by the use of mechanical splitters like the DAN-SQUID®

The system provides means for splitting a vapor-liquid stream into multiple individual streams which have substantially the same vapor-liquid ratio. The system uses an inlet static mixer to thoroughly mix liquid and distribute it throughout the vapor. The thoroughly mixed vapor-liquid is introduced into the top of a closed vertical cylindrical vessel. This patented vertical vessel with a central inlet in the top is provided with a plurality of outlets which extend radially out from the sidewall of the vessel. These outlets are equally spaced around the circumference of the vessel. As the mixture passes into the vessel it strikes an especially designer diverter element which forces the mixture outwardly through the individual outlets. The flow in each outlet is normally controlled by metering valves for the individual wells.