Publications

The Handil field is a mature oil and gas field developed since 1975, located in Mahakam Delta, East Kalimantan, Indonesia. Handil shallow reservoirs are accumulated between depth 200–1500 mTVDSS and characterized by strong aquifer support, unconsolidated permeable sandstone reservoirs with poorly sorted grain size. The wells completion requires sand control to mitigate sand production and is supported by gas lift. Gravel pack completion as sand control has been developed since 2005, with 39 wells drilled as of 2017. Gravel pack wells contribute to ~40% of total Handil field production. Several PLT and single zone tests indicate that 30% of completed zones have significant productivity impairment due to suspected fines migration. The potential of each plugged zone is low (PI < 0.5stbd/psi), with PI is only ~15% of the open hole productivity. In order to recover the remaining potential and optimize current Handil production, clay-inhibiting organic acid stimulation has been selected to dissolve fines in the critical near wellbore matrix using Hydrofluoric system and applicable for HCL sensitive formations. This paper presents successful pilot application of acid treatment starting from the concept of chemical, job procedure, challenges and constraints. Two trial jobs have been performed with encouraging results in complex job. The pilot test yielded total oil production up to 900 BOPD (4000BLPD) instantaneous gain with ~80% improvement on productivity by reducing skin from >100 to 5. On the first job, the chemical created emulsion content which was not compatible with fluid on Oil Water Treatment Unit (OWTU). Demulsifier treatment on the surface successfully diluted the emulsion. Some adjustments on chemical composition have been applied on the second job, which successfully removed the emulsion. Following the success story of this treatment on plugged gravel pack zones, more jobs are planned in Handil to improve productivity of the existing zones.