The gathering pipeline network of old block gas field have been running for a long time.

老区块气田集输管网使用年限长，管道外防腐蚀层破损严重，普遍存在腐蚀现象。

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Using gathering infrastructure that is shared across several smaller-scale biogas producers linked via a pipeline network to an upgrading facility, upgrading costs can be defrayed among all producers.

FORBES: Biogas and the Shale Gas Bonanza