However, most of undeveloped new blocks are low-grade reservoirs with many development difficulties such as super heavy oil, low permeability, thin bed and deep pay.

而尚未开发的新区大多属于超稠油、低渗、薄层或深层等开采难度较大的低品位油藏。

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Bohai 36 1 crude is classified to low sulfur naphthenic base crude oil, which is a good feedstock for producing high grade road asphalt.

渤海36 1原油属低硫环烷基原油，是生产优质道路沥青的良好原料。

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Both involve heating organic materials in a vacuum until they break down into carbon and vapors that can be condensed into a low-grade fuel oil.

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However, with the increasing difficulties of dealing with a Central Bank under sanctions, even countries sympathetic to the Syrian regime have been unwilling to go through so much trouble just to acquire Syrian oil, which, to boot, is mostly a low-grade crude needing special refineries.

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