WorldOil

In situ combustion delivers results

At Balol and Santhal heavy oil fields in the Cambay Basin, India, high mobility contrast between viscous oil and water resulted in low primary recovery, and subsequent artificial lift caused high production of water rather than oil. To increase oil production, the operator implemented in situ combustion, a thermal Enhanced Oil Recovery (EOR) process. The technique involves ignition in the well and injection of air to sustain a flame front that travels from the injection well to production wells. In this process, a small quantity of in situ oil burns (rapidly oxidizes), producing carbon dioxide, water vapor and heat, which lowers the oil’s viscosity, increases its mobility and displaces it toward the surrounding producers. ONGC Mehsana implemented in situ combustion on a commercial scale in 1997 at Balol and Santhal Fields. The technology has given the fields new life, tripling the oil recovery factor.