HPHT wells are typically associated with high complexity, technically challenging, long duration, high risk and high NPT as many things could go wrong especially when any of the critical nitty- gritty details are overlooked. The complexity is amplified with high risk of losses in carbonate reservoir with high level of contaminants compounded by the requirement of high mud weight above 17 ppg during monsoon season in an offshore environment. The above sums up the challenges an operator had to manage in a groundbreaking HPHT carbonate appraisal well which had successfully pushed the historical envelope of such well category in Central Luconia area, off the coast of Sarawak where one of the new records of the deepest and hottest carbonate HPHT well had been created. This well took almost 4 months to drill with production testing carried out in a safe and efficient manner whereby more than 4000m of vertical interval was covered by 6 hole sections. With the seamless support from host authority, JV partners and all contractors, the well was successfully delivered within the planned duration and cost, despite the extreme challenges brought about by the COVID-19 pandemic. This paper will share the experience of the entire cycle from pre job engineering/planning, execution and key lesson learnt for future exploitations.

Drilling narrow window wells conventionally have been well known to cause major wellbore issues to the Operator in the Gulf of Thailand. Therefore, managed pressure drilling (MPD) has been deployed since several years ago to mitigate the drilling problems. To ensure safety and optimize drilling time, it is necessary to identify the actual pore pressure while drilling wells with narrow marginin order to eliminate kick, ballooning and loss events. The use of automated MPD system to precisely control bottomhole pressure (BHP) during connections combined withthe evaluation of bottom up gas trend while drilling enabled the pore pressure to be predicted accurately in almost real-time condition without the need to stop drilling in the Gulf of Thailand. Thus, the narrow window wells were drilled faster with MPD, which was beneficial for the Operator in the area where the fast factory drilling was necessary to make wells more economical. Furthermore, the use of this new method in effectively determining the actualpore pressure provided solutions to the Operator in mitigating wellbore issues at the same time improving drilling timeafter several years of MPD technology implementations. The estimated pore pressure results acquired with the new methodon several narrow window wells were even comparable to the actual wireline logging measurement results. The objective of this paper is to introduce an effective and efficient method in determining pore pressure (PP) while drilling challenging wells with tight reservoir characteristic by utilizing MPD technology in the Gulf of Thailand. In addition, this paper also describes the drilling strategy, detail procedure and lesson learnedin verifying pore pressure with the new method.