As the world's population continues to grow, the energy demand is forecasted to increase directly proportional by 52% in between 2010 to 2035 (OPEC, 2013). With the oil prices predicted to be stable in the long run and expected to be as high as $165 per barrel by 2035, the search for more oil continues (OPEC, 2013). An estimation of 70% world's oil and gas production originates from mature fields with recovery at an average of 35% worldwide (Hull, 2012). This proves that there are still opportunities to recover more through enhanced primary, secondary or tertiary recovery in creating further hydrocarbon flow of a mature field.
Lower reserve with high operating and field redevelopment cost for a tertiary recovery program has deteriorate the economics for a mature field. Developing tertiary recovery for a mature field requires major modification at surface and sub-surface. Leaving the operators with the challenge to maximize recovery under current operating conditions and limited work scope of a primary recovery mainly through artificial lift method such as gas lift in oil wells.
Gas lift has been part of the primary oil recovery ever since the 1800s and the effectiveness has proven to aid the acceleration of oil recovery in a well for centuries (Gas Lift: Wikipedia, 2014). Deterioration in surface equipment and sub-surface well completion condition in a mature field, such as worsening well integrity with leaks and holes, inaccurate production metering, instability of gas compressor availability and efficiency, has resultant in the ineffective of gas lift distribution and injection downhole.
Despite the challenges faced, through prudent technical analysis and effective execution at site, the production of D-field in Malaysia has managed to increase up to 8,000 bbl/d (barrel of oil per day) instantaneously merely through production and gas lift optimization exercise.
This paper will run through the challenges faced and the technical analysis conducted in overcoming the handicap at site. This has led to the successful implementation/formulation of production philosophy and strategy to overcome challenges under different production scenarios, resulting an instantaneous production gain of some 30%. To some extent the production has been sustained and the decline arrested.