Designing and delivering a successful completion in a subsea high-rate gas deepwater environment is a great challenge in upstream field development. The complete paper covers the sand-control design and execution techniques applied to four high-rate gas wells in the operator’s Block H development in the deepwater region of Sabah offshore Malaysia in 2020 and 2021.
Field Background
PTTEP’s Block H gas development is a multifield phased subsea development designed to deliver gas to Petronas’ floating liquefied natural gas (FLNG) project known as PFLNG2. The Block H field is in the South China Sea in water depths between 1150 and 1400 m. The first phase (Phase 1A) of the project was executed in four wells between the Rotan (three wells) and Buluh (one well) fields in the midsection of the Block H development.
The reservoirs completed in Phase 1A were deepwater slope turbidite sands deposited during the Late Miocene and contain high net-to-gross reservoirs. Based on evidence from sonic logs and rock-mechanics testing performed on rotary side-wall cores and fullbore cores, all targeted reservoirs required robust sand control.
Openhole gravel packing (OHGP) was chosen as the recommended sand-control technique for the high-rate gas application, and the four wells were drilled nearly vertically, with high water standoff height as a mitigation against early water coning.
