Multilateral Well Technology Leaps into Future

Transformation of current technology is under way as Saudi Aramco aims to make producer wells reach more extensively than ever into oil bearing formations through Extreme Reservoir Contact (ERC) wells. This technology entails a quantum leap forward in multilateral drilling.

Multilateral wells, already in use across the Kingdom, tie-in several lateral branches to a vertical or horizontal main well, significantly increasing well productivity and hydrocarbon recovery. At present, the number of laterals per well is limited to four or five due to the mechanical control lines each lateral feed requires. Soon, thanks to advances made by the EXPEC Advanced Research Center (ARC), that number could increase tenfold and much higher.

"We envision 50 to 100 laterals per well to efficiently drain the reservoir and maximize economic recovery," said Muhammad M. Saggaf, manager of EXPEC ARC. "The main challenges we face are communication and power supply," he added.

Technology involving wireless telemetry and subterranean, self-contained power supplies are the constituents of the ERC well. A control module replaces the bulky hydraulic control lines, sending commands to valves and sensors, thus triggering the laterals that feed into the well. As for the actuation system, constant fluid flow from the well turns a downhole generator turbine, which converts mechanical motion into electrical power essential to the process.

The downhole power generation module resolves yet another problem. "Electrical connections between the main wellbore and each lateral are habitual trouble spots," said Nabeel S. Habib, chief technologist, Production Technology Team, "but the new technology ensures long-term operational integrity."

The new ERC technology could conceivably allow an unlimited number of "intelligent" laterals, which if properly designed, can lead to an almost linear hike in productivity and accessing previously difficult-to-reach reservoir zones.

EXPEC ARC's Production Technology Team leads this major effort which is expected to have considerable impact not only for Saudi Aramco, but for the oil industry worldwide.