Multiport Flow Selectors Optimise Oil and Gas Production Testing

By Coos van Minnen, April 3, 2013

Using multiport flow selectors (MPFS) in oil and gas applications improves production testing and reservoir management. MPFS facilitate cost-effective and compact selection and diversion of fluids from individual wells for testing, without disrupting the production from all other wells.

Testing of constituent flows is a crucial part of the production process. Oil, water, brine, condensate, gas, and other fluids must be monitored and measured regularly. Historically, wells were connected to a complex piping network. One manifold connects all well stop production. A second manifold connects the well selected for testing to a shared multi-phase flow meter or separator plus single phase flow meter set. While this conventional approach uses common valves, actuators, and piping components–it is more expensive and electrically complex than a multiport system.

Figure 1 illustrates a typical well test manifold. During normal operation, all the wells are connected to the common production and test lines. For instance, if  Well 1 needs to be tested, close valve “B” and open valve “C”.  The flow of Well 1 is then directed to the test facility while all other wells would continue to the production line.

Regardless of the test technology, individual well flow must be diverted for testing. Typical onshore oil and gas production has wells scattered over a large area, such that it is not practical to manually open and close the manifold on/off valves. The oilfield may be in remote deserts, deep jungles, or in sub-zero environments such that local 24x7 human intervention means additional infrastructure. Any scattered network of  wells  requires high investment during the green field stage of the project (CAPEX) and more maintenance (OPEX) during the operation stage. The initial CAPEX and future OPEX has a positive correlation with the spread and accessibility of the field. Consequently, the flow diversion is usually automated.

In offshore fields, it is important for platform equipment to be as light and small as practical so that the platform is less costly to construct, operate, and maintain. Developers are continually looking for technologies that make off shore platforms more economical. Compared with onshore fields, manual operations on remote platforms are more expensive.

Using a multiport flow selector

A comparison of Figures 1and 2 shows how the complex network of piping can be minimized by using a MPFS. As illustrated in figure 2 many elements like valves, control points and wiring of the conventional system can be reduced or even eliminated by implementing the MPFS system. MPFS directs multiple wells to a single production flow stream and one well in to the test system at the same time.

 Design
A multiport flow selector typically has eight inlet and two outlet connections. INLETS-Seven inlets connect to seven wells, while of ten the 8th connection is used as a parking location for the select or plug. This allows for an observation port for temporary maintenance, flushing and allows production of all seven wells if the test system is offline. The internal plug diverts one well’s fluid stream to the test