China's largest offshore shallow lithologic oilfield project, the first-phase development of the Kenli 10-2 oilfield cluster Photo: Screenshot of China Media Group's report

China's first fully automated production line for chemical-flooding polymers used in offshore oilfields began construction on Tuesday in the Nangang Industrial Zone in North China's Tianjin. Once completed, the project will enable large-scale domestic production of polymers, the core agent used in chemical flooding at China's offshore oilfields.

The project is another major move by China National Offshore Oil Corporation (CNOOC) - one of China's "Big Three" oil conglomerates - in oilfield chemicals, following the launch of the Nangang chemical plant in Tianjin in 2021. 

The newly started Nangang project focuses on polymers for chemical flooding and is both a technology upgrade and a capacity expansion built on the existing plant, the Science and Technology Daily reported.

The new construction project covers 121.54 mu (8.10 hectares) and has a designed annual capacity of 58,000 tons. 

It will include six production lines for products such as dry-powder polymers and emulsion polymers, and will be able to manufacture a full range of products, including instant salt-tolerant polymers, heat- and salt-resistant polymers, and polyacrylamide emulsions. Once completed, the project will join the existing Nangang chemical plant to form CNOOC's largest oilfield chemicals production base, providing supply support for efforts to increase reserves and output.

The project is scheduled to reach mechanical completion in September 2027. The production lines will be equipped with a distributed control system, enabling automated and precise control of the entire process from raw-material feeding to finished-product packaging, with full traceability of process data.

Since the Nangang plant went into operation in 2021, the number of oilfield chemical agents supplied under HAILOONG CHEMICAL, a brand developed by CNOOC, has grown to 18, with 95 percent of formulations developed independently by the Chinese company. The existing plant's annual supply has exceeded 43,600 tons, serving both Chinese offshore oilfields and overseas markets. 

Chemical flooding is a key method for raising oil recovery rates at offshore oilfields, and polymer flooding is the most widely used technique. High-molecular-weight polymers are dissolved in water and injected into the reservoir. By increasing the viscosity of the injected fluid, the solution advances more evenly through the formation and drives out crude oil left behind after conventional water flooding. The quality and stable supply of polymer products are essential to applying chemical flooding on a large scale.

Global Times