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Alur Siwah field is located onshore in Block A PSC of PT Medco E&P Malaka, Aceh Province. Six of the ten drilled wells proved significant gas column in Peutu limestone and Tampur dolostone. Well tests indicated gas rates in the range of 0.2 – 42 MMSCFD from selected intervals in both formations. Estimated permeability values from well tests are in range of 0.6 – 3.7 mD. During drilling campaign in 2018 three wells was drilled with total depth around 9,500 ft TVD. AS-9A, AS-11 and AS-12 wells penetrated Peutu Limestone and TD was 213 ft TVD above common GWC. These three wells were completed with open hole and pre-drilled liner, the interval length ranging from 300 to 500 ft-MD. Since Peutu limestone has low permeability the reservoir needs stimulation to increase productivity, maintain gas sales according to GSA (Gas Sales Agreement), and optimize reservoir depletion. Matrix acidizing treatment was applied to remove formation damage. The method was proven successful in previous well at Alur Siwah field in 1990’s. Peutu limestone challenges are high temperature (360 degF), high CO2 (up to 25%), high H2S content (up to 12,000 ppm), long interval open hole section (300-500 ft-MD), and water encroachment risk from water bearing zone. High temperature will accelerate acid reaction, and premature reaction might occur before reaching the reservoir. High CO2 & H2S might cause corrosion at completion string. Penetration into water bearing could cause water encroachment and water loading issue. With proper fluid selection, acid placement method, volume treatment design and execution, matrix acidizing can be applied safely and successfully to stimulate high temperature gas wells which have long interval open hole section completed with pre-drilled liner without water loading issue. This paper covers the application of acid stimulation in Alur Siwah field, well completion, post treatment well performance, best practices and lessons learned.