Fluid-Pulse Technology Boosts Oil Recovery

Abstract

Technology Update A unique fluid-pulse technology has generated impressive increases in ultimate oil recovery in applications in North and South America and the Middle East. Developed in Alberta, Canada, the fluid-pulse technology has proved its ability to recover oil previously left behind in fields thought to be depleted or uneconomical—potentially billions of barrels globally. In addition to driving the phenomenal growth of the Alberta oil sands, Canada’s oil industry has developed a depth and breadth of experience in some of the world’s harshest conditions. Those harsh conditions often create opportunities for new technologies to show their capabilities to a largely cautious industry. A recent report by the United States Energy Information Administration notes that the US imported about 45% of the 18.8 million B/D of crude oil and petroleum products it consumed in 2011. Although dependence on foreign petroleum has declined since peaking in 2005, the quest is still on for ways to increase domestic production and reduce reliance on imports. Fluid-pulse technology is one way to revive oil fields by recovering more barrels, flattening decline curves, and reducing production costs. Pulsating Injection Stream While waterflooding techniques have been used for secondary oil recovery since the 1920s, fluid-pulse injection optimization brings much higher efficiency to these methods. With most US production growth over the next 2 years predicted to come from tight rock plays in North Dakota and Texas, the fluid-pulse technology is uniquely suited to this type of tight formation, as well as being effective under many other challenging conditions. A downhole tool works with conventional surface equipment and is installed into injection wells to transform the normally steady rate of injection to a pulsating injection stream with typically 10 or more pulses per minute (Figs. 1a, 1b, and 1c). Similar to the idea of kinking a garden hose, precise amounts of energy are repeatedly built up and released by the tool. The pulses add acceleration and momentum to the injected fluid, forcing it into the reservoirs’ nooks and crannies and more impermeable rock at speeds of up to 100 m/s. This enables the injection fluid to enter pore spaces that have remained untouched. The result is a much better sweep of the oil toward the surrounding producing wells. Case Studies A small independent operator in Alberta implemented the technology with six tools in the relatively tight Viking formation in December 2010. This is a mature waterflood in sandstone with average porosity of approximately 9% and permeability ranging from 0 to 50 md. In this light oil project, production increased from the offset producers by 69 BOPD, or 52% above the base decline trend.