Foams have proved to be efficient at temporarily blocking high-conductivity layers and improving gas-injection conformance and sweep efficiency in predominantly matrix reservoir systems, at least in laboratory and field pilot tests. However, their successful use in naturally fractured reservoirs has yet to be fully demonstrated. This paper presents the evaluation process and the successful results for two foam-enhanced-oil-recovery (EOR) field pilots.
Introduction
The Recetor area corresponds to the northern extension of the larger Cupiagua field, which is 115 km northeast of Bogotá in the foothills of the Eastern Mountain chain in Colombia. The main reservoir is the Mirador formation, a quartzarenite with matrix porosities between 3 and 9% and permeabilities in the range of 0.01 to 10 md, located below 13,000-ft true vertical depth subsea.
In the Recetor area, the fracture corridors are confirmed to play an important role both in well productivity/injectivity and in interwell connectivity and gas channeling between gas injectors and oil producers.
