Use of variable-control valves enables enhanced reservoir management process in western Kuwait fields.
Jon Rawding and Michael R. Konopczynski, WellDynamics, Inc.; B. S. Al Matar, Kuwait Oil Co.
This article describes the philosophy and design of an intelligent-well installation in a water-dumpflood well in Kuwait and data analysis. The article determines that the reservoir-management capabilities of intelligent wells can lead to significant value in terms of reservoir management in this application. Dumpflooding, the method by which fluids from one formation are allowed to flow into another formation, has been used for several years in Kuwait as a means of providing reservoir-pressure support. Typically, a well is drilled to penetrate both a prolific aquifer and an oil-producing reservoir. Under the right conditions, and with a higher pressure aquifer, significant quantities of water will flow from the aquifer to the oil reservoir. As production from the oil reservoirs matures, this uncontrolled method of pressure support has led to several reservoir-management challenges, including difficulties with flood-front control, water breakthrough, conformance management and the inability to quantify the crossflow rate in each well.
With declining oil reservoir pressure, the pressure differential between the aquifer and the oil reservoir has increased, leading to destabilization of the aquifer reservoir clastic matrix from excessive drawdown and high flowrates during perforating operations. In early 2007, a West Kuwait well was completed as a controlled dumpflood well using intelligent well technology. Water from the Zubair aquifer formation flows to the Minagish Oolite oil formation in a controlled and monitored dumpflood process. Using a variable Interval Control Valve (ICV), the amount of injection fluid is regulated, while permanent downhole monitoring devices transmit pressure data to surface, enabling evaluation of the flowrate. The intelligent well also permits “soft starts” of the dumpflood to avoid borehole destabilization. The methods described in this article may be considered for improved reservoir management on a field-wide basis wherever dumpflooding is used for pressure maintenance.
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This article was adapted from a professional society paper for which World Oil was granted the right to print one time only. Therefore, to review the article, you should refer to the actual World Oil magazine in which it originally appeared.
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