KNUUD was the first High Pressure and High Temperature (HPHT) field development well embarked by PETRONAS and first in Malaysia. Learning from experience of HPHT operators in the North Sea,a detailed focus on life cycle well integrity aspect has been thoroughly emphasized throughout the well delivery phase. Initial requirement for heavy brine (16.5 ppg), which led to heavy wall production casing and high probability of tubing leak where the worst case scenarios studied in deep detail.

An extreme underbalance completion philosophy was implemented for the first time in PETRONAS. Complex processes of identifying cost effective solutions for HPHT safety critical equipment, covering the initial scoping, completing, perforating and well testing, sourcing, preparation, quality assurance and installation was systematically followed. An in-depth investigation and philosophy of managing annulus pressure build-up were also performed as part of the lifecycle integrity assurance process.

Various validation works were successfully carried out to assure the identified solutions such as V1validation (API 14L/ISO 16070) for Flow Control Equipment (4.75" Tubing Hanger Plugand 4.313", 4.188" & 4.000" Top No Go Landing Nipple's Plug), ISO 13679 CAL-IV teston completion tubing connection, API validation (API RP 19B Section IV Perforation Testing) for 2-7/8" HMX charges with maximum 6,000 psi underbalanced approach.

The well was successfully installed while recording the following significant implementation milestones for operations in Malaysia;

  1. Underbalance completion approach with freshwater instead of heavy brine (6,000 psi UB).

  2. Implementation of Vam 21 connection for 5 ½" production tubing according to ISO 13679, Connection Application Level: IV (CAL-IV).

  3. Implementation of V1 rated 15,000 psi Flow Control Equipment according to API 14L/ ISO 16070.

  4. Implementation of 15,000 psi Coiled Tubing Conveyed Perforation with deployment system& wireless depth correlation system.

  5. Implementation of annulus pressure builds up (APB) passive management with nitrogen cushion.

The comprehensive thought process and extensive efforts put in the planning stage have opened doors for significant value creation for the well delivery process. Early engagement with service providers and unique contracting approach have enabled sufficient due diligence for competitive technical solutions as well as to bring in necessary expertise to the region.

The well was successfully delivered to meet all of its objectives, producing from layers close to 16,000ft beneath the seabed. The complex process, obstacles and experiences in overcoming the challenges have indeed pioneered a confident path for future application of its kind within Malaysia and Asia Pacific region.

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