Hydroxyethyl Cellulose * Drilling Fluid

1. Viscosity enhancement

Hydroxyethyl Cellulose (HEC) is a water-soluble polymer. When it is added to drilling fluid, it can increase the viscosity of the drilling fluid. It's like adding a "glue" to a liquid, making it thicker. Proper viscosity is very important for drilling fluid because it can carry cuttings. During the drilling process, the rock cuttings produced by the drill bit breaking the rock need to be brought to the surface by the drilling fluid. Higher viscosity can ensure that the cuttings are suspended in the drilling fluid and will not settle quickly, thereby effectively preventing the accumulation of cuttings in the wellbore and avoiding downhole accidents such as drill sticking.

2. Filtration reduction effect

HEC can form a thin and dense filter layer on the well wall surface. The water in the drilling fluid will penetrate into the formation around the well wall under pressure, a process called filtration. If the filtration loss is too large, the drilling fluid will lose a lot of water, causing the drilling fluid performance to deteriorate. Hydroxyethyl cellulose can significantly reduce the filtration loss of drilling fluid and reduce the penetration of water in the drilling fluid into the formation, thereby maintaining the stability of the drilling fluid. And this filter layer is like a protective film, preventing excessive loss of liquid components in the drilling fluid. It also protects the well wall and avoids collapse accidents.

3. Suspension

In addition to carrying cuttings, HEC can also suspend solid particles such as weighting materials. In some drilling fluid systems, weighting materials such as barite need to be added to increase the density of the drilling fluid to balance the formation pressure. HEC ensures that these weighting materials are evenly dispersed in the drilling fluid and do not quickly settle due to gravity. This is critical to maintaining uniform drilling fluid density, as uneven drilling fluid density may lead to downhole pressure imbalance and cause serious accidents such as blowouts.

4. Lubrication

HEC can enhance the lubricity of drilling fluids. During drilling operations, a large friction force is generated between the well wall and the drill bit. The addition of HEC can reduce the friction during operation, greatly reduce the wear of the drill bit and extend the service life of the drill bit. At the same time, it also helps to reduce the resistance during the drilling process and make the drilling operation go more smoothly.