Publications

Liquid loading is a common issue in the production of mature gas wells in lower pressure reservoirs that have gone below dew point pressure or have active water from an aquifer. With additional hydrostatic head inside the tubing column, the well’s energy will eventually become insufficient to lift all fluid to surface. A common solution to this issue is production of the well in an intermittent fashion with cyclic shut-in/build-up and placed-on-production (SIBU-POP). This method is oppressing liquid to depleted reservoirs and accumulating gas at the tubing’s upper section by gravity. Since this method only lifts a small volume of liquid and is more efficient in wells with multiple formations that produce commingled, offloading is a potential alternative to displace more liquid. Switching the well to atmospheric pressure will allow maximum drawdown to lift more liquid and enable stable flow for a certain period. By reaching stable flow, offloading will prolong the well’s producible lifetime and give greater incremental production than SIBU-POP activities. The Peciko gas field has been on production for approximately 25 years, offloading activities have become more frequent with time as the number of weak liquid-loaded wells increase. To obtain selective offload in mature gas field with long historical offload activities, a proper offloading database equipped with strong statistical and analytical tools is needed. An offloading database will utilize programming language to automatically store all the parameters prior, during, and post offloading activities to calculate instantaneous gain and recovered gas volume. Historical instantaneous gain and well parameters were then used for further statistical and engineering review to identify key wells and define offloading strategy. This digitization approach enables selective offload candidates in Peciko field and has increased instantaneous production of 4.5 MMscfd with 1.7 BSCF cumulative incremental in 2019. However, offloading does in some respect require greater coordination and integration than SIBU-POP programs, offloading activities require additional resources such as manpower, utility boat, etc. need to be planned and executed properly to maximize gain.