PTTEP Operations Overview

Reserves at the Year-end 2020 (not including Oman Block 61) Sustained reserve life at over 5 years target MMBOE 1,800 Reserves Life* 2020 by Geography 1,647 1,622 Domestic International 10 Years 1,622 507 548 1,074 47% 1,200 1,028 7 Years 50% 53% 351 50% 600 1,140 1,074 677 2018 2019 2020 Proved (P1) Probable (P2) 5-Year Average Proved Reserves Replacement Ratio (RRR) 2018 0.7x 2019 1.5X 2020 1.5X P1 P1 + P2 2020 by Product Type Gas Liquid 1,622 1,074 31% 27% 69% 73% P1 P1 + P2 • Based on total production of natural gas, condensate, and crude oil (including LPG) of 422 KBOED for the year ended December 31, 2020 Figures include reserves from equity method 30 80 PTTEP Energy Partner of Choice

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