On 30 June 2026, S-Oil Corporation (KRX:010950) filed an amendment to a disclosure it first made on 17 November 2022. The Shaheen project's investment period, originally running from 2 January 2023 to 30 June 2026, now runs to 31 December 2026.
The amendment landed on the last day of the original window. The reason given is not a delay in the ordinary sense: the company says the end date had been written as the point of mechanical completion and has been corrected to the point at which commissioning finishes. Those are different milestones and always were.
Whether you find that persuasive depends on how you read the sentence immediately after it, which says the construction contractor has submitted mechanical completion documentation and S-Oil is currently conducting site verification, equipment performance checks and review of the submitted materials to confirm the contractual requirements have been met.
So mechanical completion is claimed but not yet accepted. The redefinition and the verification are happening at the same time.
The scale deserves stating in full because Korean investors know it and foreign ones often don't. The filed investment amount is ₩9,258bn — about $6.6bn at a rough ₩1,400 to the dollar — split into ₩7,678bn of direct spending on design, procurement and construction and ₩1,580bn of indirect costs, which the filing itemizes as capitalized construction interest and S-Oil's own labour. When the board approved it on 16 November 2022, with five outside directors present and none absent, the company disclosed the figure as 132.5% of its FY2021 consolidated equity of ₩6,988bn.
A company committing more than its entire book value to one project at one site is not a common thing.
The plant list, from the filing: a TC2C unit — crude and residue desulfurization and cracking — rated at 46,000 barrels a day; a mixed-feed steam cracker rated at 1,800 thousand tonnes a year on an ethylene basis, running on naphtha and off-gas; and polyethylene units totalling 1,320 thousand tonnes a year. Product capacities are listed as 580kt of ethylene, 770kt of propylene, 200kt of butadiene, 280kt of benzene, 880kt of linear low-density polyethylene and 440kt of high-density polyethylene.
Read the ethylene numbers together and the design intent is clear. The cracker makes 1.8m tonnes; the polyethylene units consume most of it; 580kt is listed as merchant ethylene. Shaheen is not principally an ethylene project. It is a polyethylene project with a cracker attached, built to take S-Oil's own low-value refinery streams and push them up the value chain rather than sell them as fuel.
You can watch the project arrive in the property, plant and equipment line. It was ₩9,588.0bn at the end of FY2022. At the end of June 2026 it was ₩17,757.8bn — an increase of ₩8,169.8bn, or 85%, over three and a half years.
Cash purchases of property, plant and equipment ran ₩2,185.6bn in FY2023, ₩3,041.9bn in FY2024 and ₩3,906.0bn in FY2025, with ₩1,054.9bn more across the first half of 2026. Those annual figures sum past the ₩9,258bn budget, but the cash flow line includes ordinary maintenance and turnaround spending at the existing refinery as well as Shaheen, so the two are not directly comparable.
The half-year cash figure is close to what the company described on its earnings call: first-half 2026 capital expenditure of ₩964bn, of which ₩655bn went to Shaheen, against a full-year plan of ₩2.1tn. Capital expenditure incurred and cash actually paid to contractors are different measures and a gap of roughly ₩90bn between them is unremarkable. The useful point is the direction: spending is running at about a quarter of last year's pace, which is what the end of a construction programme looks like.
Here is the awkward part. In 2026 the Korean petrochemical industry entered the largest restructuring in its history. Ten domestic producers agreed to cut naphtha-cracking capacity by 2.7 to 3.7m tonnes a year, roughly a quarter of the national total. The government approved a plan for the Yeosu complex under which Yeochun NCC, Lotte Chemical, Hanwha Solutions and DL Chemical combine assets and idle two ethylene units totalling 1.39m tonnes over three years, backed by more than ₩700bn of state support. Across China, Japan and Korea, planned closures of ageing crackers are expected to remove more than 13m tonnes of ethylene capacity by 2027.
S-Oil is bringing 1.8m tonnes online in the middle of that.
The company's answer, and it is a real one, is that Shaheen is not the kind of cracker being shut. The units coming down are small, old, standalone naphtha crackers that buy feedstock at market prices. Shaheen is integrated into a large refinery, feeds partly on residue and off-gas that had no better use, and is new. On any reasonable cost curve it starts near the bottom, and restructuring that removes high-cost supply is arguably the best thing that could happen to a low-cost entrant.
That is the bull case and I think it is basically sound. The risk is timing rather than positioning: the capacity is coming out over three years while Shaheen starts in one. Whoever is marginal in 2027 sets the price, and it will not be S-Oil, but it may still be a low price.
Three and a half years of building have shown up in the funding structure. Total liabilities were ₩20,156.5bn at the end of June against ₩10,085.6bn of equity, a ratio of 2.00, up from 1.31 at the end of FY2022. Non-current liabilities went from ₩2,916.5bn to ₩6,046.8bn.
Two things change once commissioning finishes. Capitalized construction interest — the ₩1,580bn indirect line includes it — stops being capitalized and starts hitting the income statement. And depreciation begins on ₩9tn of assets. Both land in 2027, which is why the exact start date matters more than a quarter's refining margin. Finance costs were already ₩677.6bn in FY2025 and ₩512.8bn across the first half of 2026.
The third-quarter report and whatever the company says about commissioning progress alongside it. Specifically: whether mechanical completion has been formally accepted, not merely claimed by the contractor. That acceptance is a contractual event with money attached and it should be disclosable.
After that, the first quarter in which Shaheen contributes revenue. Commercial operation is targeted for early 2027 on the company's guidance. If the fourth-quarter update pushes that into the second half of 2027, then the amendment filed on 30 June was the first of more than one, and the redefinition explanation gets harder to accept at face value.
The number to watch when it does start is not petrochemical revenue but the operating margin on that revenue against S-Oil's existing refining margin. Shaheen was sold as an upgrade of low-value streams into high-value chemicals. Either the chemicals segment earns more per barrel of feed than the fuels segment did, or ₩9.26tn bought diversification and not much else.
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