Abstract and Introduction
Mangala is a large oilfield in northwestern India containing significant volumes of moderately viscous paraffinic crude oil. The base field development plan is a hot waterflood, but due to the adverse mobility ratio between injected water and in situ oil, large volumes of water will be produced overlife along with the oil. As a result, the Operator has been examining EOR options since the field discovery in 2004, with aqueous-based chemical processes being the preferred way forward.
Oil production began in August 2009, quickly followed by startup of the water injection system in January 2010. Currently, the field is producing 125,000 bopd with injection of 140,000 bwpd. Since the Operator envisages early field-scale implementation of chemical EOR, a closely-spaced eight-well polymer-ASP flood pilot was constructed during 2010. Pilot water injection began in December 2010, less than a year after the field-scale waterflood startup.
The foundation for the analyses of any EOR pilot is appropriate reservoir characterization, and all efforts are being made to ensure that right data is collected in the Mangala EOR pilot. A key aspect of the reservoir characterization program involves multi-well pulse tests which are described in this article.