From King's Quay to decommissioning: the lifecycle of a Gulf of Mexico production platform

King’s Quay is a young platform. Murphy Oil’s semi-submersible floating production system in Green Canyon Block 433 was installed in February 2022, reached first oil that April, and is still adding wells. No one is preparing a removal application for it, and no service company should be forecasting one.

Yet BSEE’s public record already describes its end. The structure has a decommissioning cost estimate, the lease it sits on has a well and pipeline cost line, and the regulations that will one day govern its removal have been in force since before its hull left the yard. Reading a platform’s whole lifecycle in that record, from lease award to site clearance, is the clearest way to understand where the commercial signals for decommissioning work actually appear, and when.

This piece walks that lifecycle using King’s Quay as the worked example, because the record for it is complete at the front end and still empty at the back. Where it needs precedent for the final stages, it uses the handful of Gulf floaters that BSEE’s structure inventory shows as already removed.

Stage 1: lease, discovery and the obligation that attaches early

Every offshore lifecycle begins with a lease. BSEE’s lease record for Green Canyon 433, lease G35867, shows an effective date of August 1, 2016 and a block water depth of about 1,160 metres. The lease status is recorded as primary term with no expiration date entered.

The obligation to decommission does not wait for the end of that lease. Under 30 CFR 250.1703, a lessee, operating-rights owner or holder of a pipeline right-of-way or a right-of-use and easement must permanently plug all wells, remove all platforms and other facilities, and clear the site once they are no longer useful for operations. The duty exists from the moment the infrastructure exists. What the lifecycle changes is when it becomes due, and what it costs.

That distinction shapes everything that follows. The decommissioning liability of a Gulf platform is created at installation, priced by BSEE within a few years, and paid for at the end. The public record tracks all three moments.

Stage 2: sanction, build and install

King’s Quay was built as a hub. The hull, an Exmar Offshore OPTI-11000 design with four five-sided columns on a ring pontoon, was fabricated by Hyundai Heavy Industries in Ulsan under a contract awarded in 2018, and weighs roughly 11,000 tonnes. The topsides were designed to process 85,000 barrels of oil and 100 million cubic feet of gas per day, according to Murphy’s first-oil announcement, serving the Khaleesi and Mormont fields in Green Canyon 389 and 478 and the Samurai field in Green Canyon 432.

BSEE’s structure inventory records the installation cleanly. The platform appears as structure “A (Kings Quay)” on complex 2710, type SEMI, installed February 22, 2022, in 3,725 feet of water, manned 24 hours, with the removal date and site-clearance date fields empty. That empty pair of fields is the whole story of a platform’s remaining life.

The ownership of the hull was already changing before first oil. Murphy sold its 50 percent interest in the FPS itself to an ArcLight Capital Partners fund in 2021, and by first oil the facility and its export laterals were owned half by an affiliate of Third Coast Infrastructure and half by Ridgewood Energy entities, with Murphy as operator. The lease beneath it tells a similar story of shared exposure: BSEE’s lease-owner record for G35867 lists seven working-interest holders, with Murphy at 14.5 percent alongside Red Willow Offshore, two Ridgewood vehicles, and three entities carrying the Longclaw name.

That matters for decommissioning because the obligation under 250.1703 is joint and several across those parties. The Fieldwood case study shows what happens when it falls back through a chain of former owners. A platform with a private-equity hull owner, an infrastructure-fund co-owner and seven lease partners is a platform whose eventual removal will be a negotiation before it is a tender.

Stage 3: production, and the pipelines that come with it

BSEE’s production record for the structure shows first production in April 2022 and reported production in every month through May 2026, the latest month in the data captured on August 11, 2026. That is 50 producing months.

The subsea network is in the record too. BSEE’s pipeline data lists ten segments tied to the lease, including an 18,460-foot oil line from King’s Quay to a pipeline end termination in Green Canyon 432, approved in October 2021 and hydrotested in March 2022, and an 18,817-foot electric, hydraulic and chemical umbilical to the Green Canyon 389 umbilical termination assembly. Crude leaves the hub through the Cameron Highway or Poseidon systems and gas through the Anaconda gathering system, per the NS Energy project profile.

Each of those segments will one day be a pipeline decommissioning item under 30 CFR 250.1750 to 250.1754, and BSEE has already put a number on the two it counts against this lease: a deterministic pipeline decommissioning cost of about $3.5 million. That number is usually the smaller part of the final package.

Stage 4: the hub keeps growing while the record prices its end

A deepwater floater is rarely a single-field asset. Its economic life is extended by tiebacks, and King’s Quay is in the middle of that phase. Murphy told the market in 2025 that it plans four new development wells and two workovers at King’s Quay during 2025 to 2027, per Offshore Magazine’s summary of the operator’s drilling line-up, and the Longclaw project on Green Canyon 433 itself is a subsea tieback to the hub.

The record shows the exploration behind that tieback. BSEE’s eWell data holds an exploratory well, API 60-811-40764, drilled from a surface location in Green Canyon 389 to a bottom hole in Green Canyon 433, with a temporary-abandonment permit accepted in May 2023 and a borehole status of TA. That is a well that has been secured, not finished. The final plug, casing cut and site clearance for it are still ahead, whenever the operator decides it will not be re-entered.

The point for a service company is that a hub platform’s lifecycle contains many smaller lifecycles. Each tieback well is installed, produced, and eventually plugged on its own schedule. Each flowline and umbilical is a separate decommissioning item. Those are the pieces that will generate observable filings years before anyone touches the hull.

BSEE has already priced them. The lease-level cost record for G35867, updated December 2023, counts one well and two pipelines and gives the well a probabilistic estimate of roughly $29.0 million at P50, $33.4 million at P70 and $39.8 million at P90. That is a single deepwater well, temporarily abandoned, with its final P&A still to come.

Stage 5: what BSEE already says the removal will cost

The platform itself has a cost row too, and it is the most instructive line in the file.

BSEE’s platform cost estimate for King’s Quay, effective January 4, 2024, records a platform removal cost of $38,313,613 and a site-clearance cost of $700,000. The P50, P70 and P90 columns are all zero. The figures sit in a column that BSEE reports as a single deterministic estimate rather than a percentile.

That pattern is not unique to King’s Quay. In the same dataset, all 52 Gulf floating structures with a cost row carry a deterministic figure and no probabilistic range, from about $16 million for the Prince mini-TLP to about $79 million for the Tahiti spar, and every one of them carries the same $700,000 site-clearance figure. Research by LSU’s Center for Energy Studies on BSEE’s deepwater cost estimates explains why: BSEE fits its P50/P70/P90 distributions to operator-reported expenditure data, and the Gulf has too little floater removal history to fit a distribution to. For floaters, work-decomposition estimates are the only credible tool, so the agency publishes one number.

Two consequences follow. First, the $38.3 million is a modelled liability for financial-assurance purposes, not a tender value, and our P50/P70/P90 explainer explains how BOEM uses figures like it to size bonding. Second, the identical site-clearance figure across every floater is a reminder that these rows are a formula, not a survey. The number tells you how BSEE sizes the exposure. It does not tell you when it becomes work.

There is one more detail worth noting. The platform cost row is keyed not to lease G35867 but to right-of-use and easement G30428. King’s Quay sits under an RUE as well as a lease, and 30 CFR 250.1725 starts its standard one-year removal clock from the termination of the lease, pipeline right-of-way or right-of-use and easement. When the time comes, the trigger for this platform may be the RUE, not the lease.

Stage 6: the triggers that end the producing phase

A floater stops being useful for operations in one of a few ways, and each is visible in the record differently.

Depletion and lease termination. The most common path. Production declines, the last tieback stops paying, the lease or RUE expires or is relinquished, and 250.1725’s standard one-year removal deadline begins. The lease-status field flips from primary or producing to expired or relinquished, and the structure record eventually gains a removal date.

Idle Iron on an active lease. If the platform stops being useful while the lease continues, BSEE’s NTL 2018-G03 applies a standard five-year working timeline for platform removal from the date it is no longer useful. The Idle Iron explainer covers how that clock is read and why it is a timing signal rather than a fixed date.

Damage. The Typhoon mini-TLP in Green Canyon 237, installed in 2001, appears in BSEE’s inventory as removed in 2006 after Hurricane Rita capsized it. Storm loss is the one path that skips the decline phase entirely.

Economics and redeployment. A floating hull can be disconnected and reused. This is a real difference from a fixed jacket and it changes the disposition question at the end. The hull owner, not just the operator, has a say in whether the structure is scrapped, reefed or sold on.

For King’s Quay, none of these triggers is in view. The hub is four years old, is adding wells, and has a producing-months count that is still rising every month. The record is telling you what will eventually happen and roughly what BSEE thinks it will cost. It is not telling you when.

Stage 7: the removal sequence for a floater

When the trigger does arrive, the sequence for a floating production system differs from the jacket removal described in our platform removal lifecycle in several ways that matter to the service market.

1. Subsea well P&A. Every tieback well is plugged under 30 CFR 250.1715 and its wellhead and casing removed under 250.1716, standard depth 15 feet below the mudline. For King’s Quay’s wells in roughly 3,600 feet of water, the alternate-depth provisions for water deeper than 800 metres are relevant, and BSEE can approve leaving more in place where there is no obstruction risk.
2. Flowlines, umbilicals and risers. Production risers must be flushed with seawater before removal under 250.1725, and each pipeline segment is decommissioned in place or removed under its own approval. This is a marine-construction scope, not a heavy-lift one.
3. Mooring disconnection and anchor recovery. A semi-submersible is held on station by mooring lines and anchors, and their disconnection and recovery is a scope that does not exist for a jacket. Acteon’s account of the Red Hawk spar removal lists mooring-line disconnection, ballasting for topsides removal, riser pull-tube cutting and tow preparation as the core packages.
4. Hull disposition. The hull is deballasted and towed. It may be scrapped, reefed under 250.1730 if a state programme accepts it, or redeployed. Red Hawk was reefed at Eugene Island 384, the first spar ever placed in a reef programme, as our Rigs-to-Reefs explainer discusses.
5. Site clearance. Under 250.1740 to 250.1742, the site is cleared and verified, and the structure record finally gains a site-clearance date.

Planning horizons for this sequence are long. Anadarko began planning Red Hawk’s removal in 2011 for an operation completed in September 2014. That three-year lead is the window in which the service-company opportunity is actually won.

What the removed floaters tell you about timing

BSEE’s structure inventory, as captured August 11, 2026, shows 50 floating production structures standing in the Gulf: 17 semi-submersibles, 15 spars, 13 tension-leg platforms, 3 mini-TLPs and 2 FPSOs. King’s Quay is among the youngest in that list. Only Vito, Argos, Anchor, Whale, Shenandoah and Salamanca were installed after it, between late 2022 and mid 2025.

The same inventory shows the floaters that have already gone. Setting aside the shallow-water mobile units, the removed list reads:

Structure	Type	Installed	Removed	Water depth (ft)	Service life
Red Hawk, GB 876	Spar	2004	Sept 2014	5,300	10 years
Gomez, MC 711	Semi	2006	Feb 2014	2,975	8 years
Independence Hub, MC 920	Semi	2007	Dec 2019	8,000	12 years
Morpeth East, EW 921	Mini-TLP	1998	Apr 2021	1,700	23 years
Neptune, VK 826	Spar	1996	Aug 2023	1,930	27 years
Genesis, GC 205	Spar	1998	June 2024	2,590	26 years
Jolliet, GC 184	TLP	1989	June 2025	1,760	36 years
Nansen, EB 602	Spar	2001	Jan 2026	3,675	24 years

Source: BSEE Platform Structures dataset, removal-date field, as captured August 11, 2026.

Three things stand out. Service lives range from 8 years for a fast-declining gas hub to 36 years for the Gulf’s first TLP, so a floater’s age tells you very little on its own. The tempo has changed: Oil & Gas Journal counted only three floater removals in the region’s first 25 years, and the record now shows one a year since 2023, with Nansen’s site-clearance field still empty. And each of those removals appeared in the public record years in advance, first as a lease-status change, then as well P&A filings, then as a removal application, exactly the chain that GOMDecom’s radar is built to read.

Where the service-company signal actually sits

For a young hub like King’s Quay, the honest answer to “when is the decommissioning opportunity?” is: not the platform, and not yet. But the lifecycle view points to what to watch instead.

• Tieback wells, individually. Each well feeding the hub has its own Idle Iron clock and its own cost line. The temporarily abandoned exploration well on Green Canyon 433 is already a future P&A scope with a P70 estimate of $33.4 million attached to the lease.
• Flowlines and umbilicals. When a satellite field depletes, its flowline and umbilical can be decommissioned while the hub keeps producing. That is a marine-construction package that appears as a pipeline decommissioning approval, not a platform removal.
• Ownership transitions. Seven lease partners and a two-party hull ownership will generate assignment records. A change of operator or the exit of a fund is a stronger early signal than any age-based rule.
• Lease and RUE status. The platform’s removal clock will start from the termination of lease G35867 or RUE G30428. Both fields are in the record and both are worth watching once production starts to decline.
• The removal application itself. By the time a final removal application for the hull appears, the mooring, tow and disposition packages will typically already have been scoped by the operator. The three-year lead seen on Red Hawk is where the pursuit happens.

The record for King’s Quay will fill in from the front. Producing months will keep climbing, new wells will appear in eWell, and the cost rows will be revised. The removal-date and site-clearance fields will stay empty for a long time. When they stop being empty, the useful signals will have been visible for years.

GOMDecom’s sample Opportunity Brief shows how those signals are separated from a platform’s static cost estimate, and the methodology explains how source facts like the ones in this piece are kept distinct from the inferences drawn from them.

Sources

• Bureau of Safety and Environmental Enforcement, Data Center: Platform Structures, Platform Production, Pipelines, Lease Owners, Decommissioning Cost Estimates and eWell APM datasets, as captured by GOMDecom on August 11, 2026.
• Murphy Oil Corporation, Murphy Oil Corporation Achieves First Oil at King's Quay Floating Production System in Deepwater Gulf of Mexico, April 11, 2022.
• Offshore Technology, Murphy Oil sells stake in King's Quay floating production system, March 2021.
• NS Energy, King's Quay Floating Production System (FPS), Gulf of Mexico, USA.
• Offshore Magazine, Murphy discloses US Gulf drilling line-ups for 2025-27, May 8, 2025.
• Electronic Code of Federal Regulations, 30 CFR Part 250, Subpart Q — Decommissioning Activities, especially §§250.1703, 250.1716, 250.1725, 250.1728, 250.1730 and 250.1740–250.1754.
• Bureau of Safety and Environmental Enforcement, NTL 2018-G03 — Idle Iron Decommissioning Guidance for Wells and Platforms.
• Oil & Gas Journal, Deepwater Gulf decommissioning—2: Structure inventory runs gamut of deepwater technologies.
• Kaiser, M. J., BSEE decommissioning cost estimates in the deepwater US Gulf of Mexico, Ships and Offshore Structures, Vol. 19, No. 2.
• Acteon, Acteon safely decommissions Red Hawk Spar, Gulf of Mexico's deepest floating platform; Offshore Magazine, Red Hawk stands as first spar ever decommissioned in GoM.