On an independent refiner's feedstock ledger, the non-state crude import allowance is a hard ceiling. The annual volume set by regulators caps how much crude a private refiner can clear through normal customs import; burn through the quota early and you hit mid-year with idle units and no feedstock.

In tight-quota months, refiners pivot to bonded and transshipment spot barrels. ESPO reaches Shandong from the Russia–China pipeline's eastern leg in just 3–4 days; Urals takes ~40 days around the Cape of Good Hope but carries a deep discount; Oman and Dubai lean on steady Middle East term supply. SNSUC's seven transshipment grades — ESPO, Dubai, Oman, Urals, Basrah Light, Bonny Light, Lula — are sliced precisely along short-haul, deep-discount, and stable-supply lines to match each phase of a refiner's restocking.

For the operator the read is straightforward: when quotas are loose, landed duty-paid cost drives procurement; when they tighten, the discount and freight math on transshipment spot is the decider. With USD/CNY at 6.7118 and the yuan firming, delivered transshipment prices fell further, making spot restocking cheaper than drawing down quota.