Nigeria's latest effort to combat theft could imperil its oil income lifeline, compounding the damage the crude price fall has done to its finances, access to dollars and imports.
Oil traders and shipping brokers said a newly implemented "letter of comfort" requirement under which vessel owners must sign a guarantee that their ships will not be used for theft has made it more difficult and expensive to load Nigerian crude, putting some buyers off.
A copy of the letter draft seen by Reuters asked vessel owners to "guarantee to indemnify" the government and national oil company NNPC against any illicit use of their vessel, which led some owners to reject pending bookings. Traders say others are refusing future requests for now.
"Nobody is coming forward for offering the vessel and whoever is willing to go to Nigeria is asking exorbitant rates," said K. Namdeo, head of refineries at India's HPCL, adding they would "be cautious in future" about buying Nigerian crude.
Tanker owner Heidmar rejected an HPCL Nigerian fixture due to insurance concerns over the letter. Finding a replacement proved difficult. Provisional fixtures showed the MT Solana sailing to West Africa for HPCL, but the vessel turned away from Africa, according to tracking data, and is now en route to the Bahamas without oil.
Fixtures showed the refiner putting two Suezmax vessels on subjects for the journey, which typically adds to costs.
Some European buyers are also now treading carefully with Nigeria.
An oil trader for one Mediterranean refiner said they "will not touch a single drop of Nigeria crude until this matter on the letter of comfort is solved."
There is little disagreement that Nigeria needs to fight oil theft, which President Muhammadu Buhari has said siphons as much as 250,000 barrels per day (bpd) of crude of its nearly 2 million bpd of production.
Industry sources said an initial effort, the banning of roughly 100 oil tankers that came from Buhari's office in July, was too blunt an instrument. But in lifting that ban earlier this month, it added the letter of comfort with immediate effect, which sources said applied to all vessels, creating a potentially bigger problem.
Oil tanker industry association INTERTANKO said the letter as drafted would give Nigerian authorities a "blank cheque" for any perceived violations.
"NNPC's guarantee terms would allow the Nigerian authorities to impose an arbitrary penalty for breach of local law - of which owners might be unaware - and then demand an indemnity for their losses without the need to prove any loss," said INTERTANKO's General Counsel Michele White, adding "owners' insurance would not respond to that."
Shipping sources said that in addition to Heidmar, Asian companies China Shipping and AMCL will not call at Nigerian ports for the time being, nor will Greece's Chandris.
None were able to comment immediately.
Other vessel owners are working around it with watered down language, traders said. But it has contributed to a marked rise in freight; the cost of booking a Suezmax tanker from West Africa to the United States spiked by 80 cents late last week to $2.75 per barrel, according to JBC Energy.
Rates for Very Large Crude Carriers (VLCCs) to Asia rose by 20 cents to around $3.40 per barrel.
The increase could deter buyers.
"It's making the arbitrage less workable," said Eugene Lindell, JBC's senior crude market analyst. "This ultimately means the crude prices would have to be depressed so you can shift the barrels."
For Nigeria this is a serious concern. The October loading programme was its highest of the year, and its price differentials to benchmark dated Brent had begun to rebound on the back of European and U.S. buying.
In a country staring down a potential oil price collapse-induced recession, any hit to income is a problem.
"The revenue impact will be significant," said Dolapo Oni, head of energy research with pan-African lender Ecobank. "Due to the expensive freight, we are likely to see differentials weaken considerably, which means we could have lower revenue than normal."