Awi A-4 Comprehensive Well Evaluation for Successful Well Intervention Program

Abstract

AWI A-4 well has the highest Non-Condensable Gas (NCG) content among other production wells in the Salak field with NCG content 10%-wt. NCG interference study indicated that AWI A-4 has the most substantial connection/interference to several surrounding high NCG wells. AWI A-4 encountered wellbore obstruction (scaling) in 2012, which increased the NCG content of surrounding wells and power plant Unit-4, causing generation loss. Another impact is steam supply reduction by 71.8 kg/s because of maintaining Unit-4 NCG content below its maximum Gas Removal System (GRS) capacity by 2%-wt. Wellbore scale clean out was conducted in 2015 but failed and even plugged the wellbore. A comprehensive evaluation of well AWI A-4 wellbore condition and well characterization was conducted involving a multidisciplinary team (Drilling, Reservoir, Production, Geochemistry) in order to obtain a better understanding of the main cause of well AWI A-4 wellbore plug then develop the proper method to clean the wellbore plug and improve wellbore accessibility. After evaluating well AWI A-4 wellbore condition comprehensively, a new scale clean out program was developed using rotojet Coiled Tubing Unit (CTU) in 2017 which was finally able to improve wellbore accessibility well AWI A-4 including NCG content reduction of surrounding high NCG wells and power plant Unit-4. This successful wellbore accessibility improvement has a positive impact on additional/incremental steam supply by 84.4 kg/s, including other steam supply projects delay and cancellation, so that reduce the company’s operational cost.