The following are the main functions of bentonite in drilling:

(1) Pulp making: The main purpose of using bentonite in drilling is to make slurry to protect the wall. Good quality bentonite has a very strong slurry making ability and a high slurry yield.

(2) Wall protection: The high-quality mud produced by bentonite for drilling can penetrate and bond the easily collapsed sand and gravel gaps around the well wall, thereby effectively protecting the well wall and preventing hole collapse.

(3) Cooling the drill bit: When the drill bit is cutting with the sand and rock debris at the bottom of the well, it is easy to generate high temperature and cause the accident of burning the drill bit. The bentonite mud pours out continuously from the grouting of the drill pipe to the gap at the top of the drill bit, which has a better cooling effect on the drill, thereby preventing the burning of the drilling tool and reducing losses.

(4) Filtration reduction: Adding a certain proportion of bentonite to the drilling fluid can effectively reduce the water loss of the mud, thereby improving the performance of the drilling fluid.

(5) Increase shear force: bentonite can significantly increase the viscosity value and shear force value of drilling mud.

(6) Stability: Bentonite mud forms a thin mud cake around the well wall, which can reduce the penetration of moisture in the drilling mud to the well wall, form a water-resistant layer and an impermeable wall, and prevent the expansion of the wellbore during drilling, thereby Play a very good role in protecting the stability of the well wall.

(7) Cleaning: The high-viscosity bentonite mud is driven into the bottom of the well along with the holes in the drill pipe, which can take the cuttings in the bottom of the well out of the well and keep the bottom of the well clean for a long time.

(8) Decompression: The strong lubricity of bentonite can effectively reduce the drilling resistance.

(9) Collapse control: Drilling cannot be completed immediately due to various reasons, and the well wall is prone to collapse due to long-term immersion in groundwater. At this time, high-viscosity bentonite mud can be injected into the well to prevent the well wall from collapsing.

(10) Sealing slurry: After the drilling is completed, it is generally necessary to use bentonite with sealing slurry in the section where the well is prone to collapse.

(11) Balance surface pressure: bentonite mud can balance formation pressure and prevent water gushing and water penetration accidents in wells.

(12) Configure oilfield drilling fluid: Bentonite has good rheology and portability in oilfields, so it can be equipped with high-performance oilfield drilling fluid, oil-in-cement slurry and high-temperature anti-jamming agent, effectively improving oilfield drilling speed and reducing Drilling construction takes place.