* Nembe Creek pipeline carries around 150,000 bpd
* Shell says oil thefts running at highest for three years
* Nigeria military accuses Shell of failing to plug leaks
By Joe Brock
ABUJA, March 4 (Reuters) - Shell may be forced tocompletely shut down its 150,000 barrel per day Nembe Creek oilpipeline in Nigeria due to an "unprecedented" amount of oiltheft, the company's local unit said on Monday.
The Nembe trunkline is one of the most important productionroutes for Africa's top crude oil exporter, feeding thebenchmark Bonny Light export terminal. The pipeline was replacedin 2010 at a cost of $1.1 billion, Shell says.
A spokesman for Nigerian security forces in theoil-producing Niger Delta said they were having successesagainst oil thieves. He denied that there was any surge in theftalong the Nembe line, accusing Shell of failing to seal leaks.
Criminal gangs frequently tap into exposed pipelines in thewinding creeks and waterways in the Niger Delta. Some of thecrude is refined locally but the majority is transferred ontolarger ships offshore and sold internationally.
Oil theft also has a devastating environmental impact,destroying fishing communities and poisoning water used fordrinking and bathing in parts of the Niger Delta.
Flowstations on the pipeline were shut down three timesbetween Feb. 22 and Feb. 25 due to thefts, with each incidentdeferring 150,000 bpd of production, Shell said in a statement.
"It is getting to the crunch that rather than allow peopleto continue to attack my pipeline and devastate the environment,I may actually consider shutting in the pipeline completely,"Shell Nigeria managing director Mutiu Sunmonu said.
"...The situation in the last few weeks is unprecedented.The volume being stolen is the highest in the last three years;over 60,000 bpd from Shell alone," he said.
Even taking the theft into account, shutting the pipelinewould be a drastic move that would cost Shell up to 150,000 bpdof production revenues.
Lieutenant Colonel Onyema Nwachukwu, a spokesman forNigerian forces in the Niger Delta, said a crackdown on oiltheft meant it was on the decrease, adding nearly 2,000 suspectshad been arrested since it was launched last year and more thantwice as many illegal refineries destroyed.
More than 100 oil barges had also been destroyed, he said.
"It's therefore quite difficult to reconcile the upsurge (inoil theft) spoken of by SPDC (Shell Petroleum DevelopmentCorporation) given these record achievements," he said.
"The JTF (joint task force) does not have the man power toput operatives permanently on over 6000km of pipeline."
He said SPDC - a Shell-run joint venture majority owned byNigeria's state oil firm - had been alerted to numerous ruptureson pipelines but had failed to seal them, including on theDasaba and Mekakiri creeks. Local communities also sometimesaccuse Shell of failing to seal leaks.
"Till date, SPDC has done nothing to salvage the situationand yet it is issuing undue threats of shutting down ... The JTFdoes not have the expertise to clamp them, SPDC does," Nwachukwusaid.
Nigerian Oil Minister Diezani Alison-Madueke said last monththe thefts were the work of international crime syndicates andshe had requested help from Britain to tackle the problem.
Security experts say they believe Nigerian officials must becomplicit in the business, considering the scale of theft, whichsome oil companies have estimated at around 150,000 bpd acrossthe whole of the industry.