Publications

Nilam is one of major fields operated by VICO Indonesia under the Sanga Sanga Production Sharing Contract (PSC) which has been producing for over 43 years. Today, Nilam has reached a mature stage of its life where most of reservoirs are much depleted from their initial pore-pressure condition with an average recovery factor of 68%. Drilling is the main development contribution to sustain Nilam production, however the downturn of oil & gas industry in 2015 due to low oil price had great impact on development drilling program. As a result, after 2015, Nilam field decline rate increased from 12% into 30% in yearly average. In order to adapt with the situation, the development strategies shifted to aggressive rigless program in existing wells to arrest production decline. By the time,remaining potential zones are locked in the depleted zone or low permeability reservoir, which lead to less productivity and lower chance of success for commercial flow. As the result, VICO team began to step out from conventional review to unlock potential zones candidates in existing wells using detailed integrated reservoir assessment. This paper will describe several success strategies which have been applied to identify additional reservoir opportunities in existing wells since the last 3 years. The strategies are, chasing remaining by passed zones from old wells, unlocking potential reserve from un-prognosed zones and shallow potential and applying cement packer methods to rejuvenate old wells. The application of these strategies has already contributed 3.8 Bcf and 164 thousands of barrel oil to Nilam production with success ratio 79% in average. In summary, these strategies have successfully unlocking hydrocarbon potential and maximizing recoverable reserve in existing wells which resulted in extend the field life.