In 2004, the large Mangala, Aishwariya, and Bhagyam oilfields were discovered in the remote Barmer Basin of Rajasthan, India. These fields contain light, paraffinic crude oils with a wax appearance temperature approximately 5°C less than reservoir temperature, and in situ viscosities that range from ~8cp to ~250cp. Development plans for these fields are based on hot waterflooding to prevent problems with in situ wax deposition.
This paper discusses a few issues associated with waterflooding viscous oils, presents some viscous oil waterflood results from around the world, and benchmarks the expected performance of the Rajasthan fields to this database. Given that the Rajasthan oils have some properties that may be considered "unusual" and potentially troublesome for waterflooding, and that there is no long-term production data or a history-match of waterflood performance in hand, these benchmarks were considered very important reality checks. In actual fact, fields with similar or much higher viscosities are routinely waterflooded with excellent recoveries in Canada, the USA and elsewhere.