The reasons for controlling mud loss are:
1. Maintain wellbore integrity: in order to protect water-sensitive shale and reduce wellbore erosion to better implement casing cementing work.
2. In order to reduce the filtration loss to the production layer, reduce the formation damage.
3. Reduce problems in logging analysis.
Sodium carboxymethyl cellulose (CMC) is a plant product used to control fluid loss and as a thickener.
1. In the concentration of low and moderate ion pollution, CMC is active, so it is suitable for inhibiting mud. The chloride content does not exceed 60,000 mg/l.
2. There are low-viscosity grade and high-viscosity grade CMC to choose from, depending on the degree of viscosity increase desired. Industrial-grade CMC is usually preferred.
3. The temperature stability of the additive can reach 400°F.
1. It may be necessary to use a diluent to offset the viscosity-increasing effect of the additive.
2. In some salt muds, it may cause viscosity reducing effect.