The Application of Sodium Carboxymethyl Cellulose - Petroleum Industry

For example, during the drilling of a deep well in the Middle East, if the wellbore was not cleaned properly and rock debris accumulated, it would lead to the risk of sticking. In this case, the addition of a medium-viscosity CMC to the drilling fluid would increase its viscosity and enhance its suspension ability, thereby avoiding complex situations downhole.

During the drilling process of a certain shale gas well, micro-fractures in the formation developed, and the drilling fluid experienced severe filtrate loss, resulting in instability of the well wall. By adding CMC (a low-viscosity type) to the drilling fluid, a dense filter cake was formed, effectively reducing the filtrate loss.

During drilling in a certain salt-bearing layer in Xinjiang, the conventional polymers failed due to the high-salt environment. Therefore, salt-resistant CMC (such as PAC or a combination of CMC and sulfonated polymers) was adopted to maintain the performance of the drilling fluid.

In a certain environmentally sensitive area of the Bohai Sea, biodegradable drilling fluid is required. A non-toxic drilling fluid is prepared using CMC as the main agent (combined with other natural modified materials), which has passed environmental protection certification and meets the drilling performance requirements.

In a certain high-temperature well in Kuwait (with a bottom temperature of 180℃), a modified CMC with high-temperature resistance (such as when combined with lignite resin) was used to enhance thermal stability.

A certain shallow oil field in Africa needs to reduce drilling costs. By replacing some synthetic polymers with CMC (cementing material), and configuring a low-cost water-based drilling fluid, the cost can be effectively reduced by 20%, and it can also meet the technical requirements for shallow wells.

In conclusion, CMC is of great significance in the petroleum industry. However, it is also important to pay attention to the selection of the type. Low-viscosity CMC is used for reducing fluid loss, while high-viscosity CMC is used for thickening.

In terms of compatibility, it needs to be compatible with other additives (such as polyionic cellulose PAC, sulfonated asphalt).

The limitation of CMC lies in the fact that it requires the use of other high-performance polymers when working in extremely high temperatures (>200℃) or in extremely salty environments.