Development of an Osmotic Membrane Pressure Actuator for Enhanced Oil & Gas Recovery

The OMPA project aims at developing a membrane suitable for being fitted in a valve which will operate according to an osmotic principle,and which will be able to close down a sidestream in a branched gas/oil well if it starts to produce water. By closing off the water producing sidestream the rest of the well can continue to operate without having to close down. The membrane will thus be permeable to the water, and by permeating into the draw solution on the other side of the membrane, a pressure will bu ild up and the actuator will be triggered to close the valve. This operation will be reversable if needed.

One of the pronounced challenges in sub-sea oil and gas production is to avoid intrusion of water into the oil wells. The production of water is mainly restricted due to the flow line and the topside process capacity. The development of longer and more so phisticated horizontal wells have been the most important step towards better utilization of the reservoir due to increased drainage area which leads to an increased recovery of gas and oil. One of the challenges in exploiting gas and oil wells is often t he heterogeneity of the reservoir which increases the probability of water intrusion. For both gas and oil production the ultimate solution would be to separate out the water from the gas or oil in the wells. Using membrane technology for this purpose ha s been considered in a SINTEF Project initiated by Norsk Hydro back in 2002. In the current project it is proposed to use the same underlying idea for a gas condensate well to avoid having to close down wells if/when some branches starts to produce water and thus avoid expensive subsea operations. The planned activities in the project are to explore theoretically and experimentally the restrictions of a membrane suitable for an activator connected to a valve. Based on this knowledge existing membranes m ay be modified or new efficient membrane materials developed. The partners in the project represent a very strong team which holds comprehensive knowledge and experience within all fields needed for this challenging concept: Membrane material knowledge (N TNU), membrane characterization (ITM-CNR), polymer synthesis (Sintef), instrumentation design (InflowControl), knowledge on gas-oil wells (Statoil). The actuator is based on the principle of pressure retarded osmosis (PRO) where the feed side of the actu ator is the water/oil/condensate flow and the permeate side is a draw solution, i.e. water saturated with salt. A successful development of an OMPA actuator has a large potential for further value creation.