Publications

Total E&P Indonesie (TEPI) currently produce ±1600 MMSCFD of gas from 5 major gas fields, Tunu, Sisi-Nubi, South Mahakam, Peciko and Tambora. Excluding South Mahakam and Sisi-Nubi, all other fields are mature and in declining production. On some very sensitive gas wells, liquid loading problem, the inability to continuously lift liquid from the borehole has been observed. The accumulated liquid increases hydrostatic pressure and eventually stop the well production. As a solution, TEPI introduced a “Foam Assisted Lift (FAL)” technology in 2011 as a pilot phase, which continued in 2012-2013 on more wells part of the FAL trials. The principle of FAL is to generate bubbles to reduce hydrostatic pressure, through surfactant injection from surface to down-hole using capillary string (CS) set under specific well intervention arrangement. Starting from the pilot phase, TEPI has developed and improved several robust down-hole equipments, operation, as well as the selection criteria of candidate wells. TEPI has defined the selection method and criteria of good FAL candidates based on the following factors, good productivity (defined as Porosity x Net pay thickness), good offload response, condensate and liquid ratio less than 60%, and bottom hole shut in pressure higher than 1000 psi. The new selection criteria was fully implemented in the 2015 campaign, and resulted in improved production in 10 wells. FAL is considered as proven technology to maintain production stability of very sensitive gas wells. Keywords: Capillary string, liquid loading, foam assisted lift, selection criteria