In the 1970s, large foreign CMC companies launched cellulose ethers for temperature-resistant and salt-resistant seawater drilling fluids, called "PAC”, which were kept secret from the outside world for a long time.After sampling and analysis, it was found that the so-called "PAC" and “carboxymethyl cellulose CMC" have the chemical structure.On the essence.It is close to the above, but has excellent application performance. It is used as an anti-filter loss agent, which has a higher pulping capacity than ordinary CMC, low API water loss and good temperature resistance.The performance is mainly manifested in various concentrations of saline solutions, which show good adhesion, thermal stability and rheological properties of the solution, which has greatly broadened its application in petroleum extraction and many other fields.The production method of polyanionic cellulose is mainly to alkalize cotton fleece with high cellulose content in a uniform liquid slurry suspension state to become alkaline cellulose, and then etherize it with chloroacetic acid to make products of different specifications according to the different degrees of etherization.Compared with CMC, PAC has a high average degree of substitution and a uniform distribution of residues.Differences in technology have caused huge differences in products. The reason should be attributed to the particularity of the polymer structure of natural cellulose and the many complexities in the industrial production of cellulose ethers.

The excellence of PAC applications is specifically manifested in:

a.High degree of substitution, good uniformity, high transparency, viscosity control and water loss reduction;

b.Suitable for any water-based mud in fresh water or seawater, saturated brine;

C.The mud formulated with this product has good water loss reduction, preparation and high resistance

Temperature characteristics;

d.The mud formulated with this product is rheological and can be prepared in a high-salt medium.

The dispersion and expansion of soil and shale, so that the pollution of the well wall is controlled;

e.Stabilize the soft soil structure and prevent it from being due to the water level.Collapse of the well wall caused by rising;

f.When the well drill passes through the rock surface, slow down the accumulation of drilling solids in the mud;

g.Suppress the turbulence in the drill pipe, so that the reflux system maintains a minimum pressure loss;

h.Enables the mud to increase the amount of pulping and reduce the amount of filtration loss;

i.Can stabilize the mud foam.