The Lematang Block in South Central Sumatra have an estimated total reserve of 330 BCF, the expected production life of 10 years is of substantial importance to MEDCO the fields operator. Wells in this field contain 32% CO2, 100-ppm H2S, BHP of 10,500-psi and BHT 408 degF and are therefore categorized as HPHT gas wells. The initial two wells were completed by the previous operator using 22Cr tubular material and 13 Chrome based material accessories. However, operational difficulties from material deterioration were identified. Optimization of the completions durability with the consideration of the economics of the completions was of paramount concern when selecting the materials and the completion tool designs.