Abstract
Discovered in 1944 and placed on production in 1952, the Minas Field has produced 4.25 billion barrels of oil to date (47% recovery). Current production average is 126 MBOPD with 5,200 MBWPD. This huge volume of water needs to be managed effectively because its potential environmental impact and water handling cost. These two reasons triggered the need of extensive water management program.
The water management programs in Minas are divided on surface and subsurface strategy. The surface strategy emphasizes more on avoiding any environmental impact. Starting on late 1995 "Zero Water Discharge" program was implemented by means of re-injecting all of produced water from all 6 (six) gathering stations. The subsurface activities emphasize on reducing water production, which is unavoidable process in oil industry. In early 2000, the subsurface strategy of limited open sand perforation was implemented and is able to flattening oil production decline while also reducing water production significantly.
This paper describes the strategy of the Minas Operating Unit (OU) on surface and subsurface activities on continuing its effort on handling its produced water while also attaining zero water discharge to the environment as part of its water management program.
Surface activities are included monitoring produced water in each gathering system, stream water and sediment, quality of injection water and shallow ground water, as well as improving water injection equipment. Ensuring no subsurface water injection leaking to ground water by conducting surveillance, improving injectivity, reducing water production, and effort on water injection reduction to productive zone are the current subsurface activities.
All the above effort have added tangible and intangible value to Minas operation. Tangible value came from reduction in operating cost by $ 14.6 million in year 2001 by reducing 800 MBWPD. Preserving our environment for future generations is the highest value (intangible) of this program.
