Drilling mud with different composition required in different sites or different drilling depths, so we need to do real-time adjustment of the drilling fluid, here are a few common adjustment methods.

1. The main advantages of polymer drilling fluid

(1) The drilling fluid density and solid content is low, and therefore it is easy to increase drilling speed, the degree of damage to the reservoir is also smaller.

(2) Shear thinning properties of drilling fluid is strong. Under the certain displacement of pump , the viscosity of the annulus fluid, shearing force are high, and therefore this drilling fluid has a strong ability to carry the cuttings; in the high shear rate of bit nozzles, the flow resistance of the fluid is smaller, it is beneficial to increase drilling speed.

(3) The role of polymer treating agent has strong coating and restrain drilling cuttings dispersion, this is conducive to maintaining wellbore stability.

2. The method to improve the drilling fluid shear force

(1) To improve the content of solids in drilling fluids.

(2) To improve the dispersion of clay particles.
 

(3) Add a suitable electrolyte (such as NaCl, CaCl2, lime, etc.).

(4) Add water-soluble polymer.

3 The method to increase the viscosity of drilling fluid

(1) To improve the solid content.

(2) Make the solid particles form to the local network structure.

(3) Add water-soluble polymer.

(4) To improve the dispersion of the solid phase.

4. The method to reduce the drilling fluid density

(1) Use shale shaker, cyclone desander, mud drilling fluid desilter and decanting centrifuge to clear cuttings,sand and other harmful solid phase in drilling fluid, reducing drilling fluid solids content, thereby reducing the density.

(2) Add water to dilute.

(3) Add a certain amount of blowing agent.

(4) Use chemical flocculants, so that part of the solids particles conglomerate, precipitate and reduce density.