An extra-heavy-crude-oil field in Venezuela has been developed by use of multilateral wells. After the initial single-lateral wells were brought on production, an opportunity was identified to change the development program to multilateral wells to increase production rates. The geometry of multilateral wells was designed to fit the actual sand distribution and depositional environment. Various forms of multilateral wells were drilled. The result was an increase in individual well production rates that is nearly proportional to the effective lateral length connected to the wellbore. The costs were lower than possible with single-lateral wells of the equivalent length.