What are petroleum drilling fluids mud additives?

What are petroleum drilling fluids mud additives?

Drilling fluid is a circulating fluid that meets the needs of drilling operations has multiple functions during the drilling process. Drilling fluid is the blood of drilling fluid, also known as drilling fluid cleaning fluid. According to the composition of drilling fluid, drilling fluid can be divided into clean water, mud, clay free phase washing fluid, emulsion, foam compressed air. Clear water is an early drilling fluid that has been treated is easy to use. It is suitable for intact rock formations areas with sufficient water sources. Mud is a widely used drilling fluid, mainly suitable for unstable pore walls such as loose, fractured, prone to collapse, water expansion peeling.

Drilling fluid has at least the following ten functions:

Clean the bottom of the well carry rock debris. Keep the bottom of the well clean, avoid repeated cutting, reduce wear, improve efficiency.

钻Cooling lubrication of the head drill string. Reduce the temperature of the drill bit, reduce drilling tool wear, improve the service life of the drilling tool.

Prevent pollution wellbore collapse of oil gas reservoirs.

Balance (control) formation pressure, prevent blowout leakage, prevent contamination of drilling fluid by formation fluids.

Suspended rock debris weighing agent. Reduce the settling speed of rock debris avoid sand settling.

Sand rock debris can settle on the ground.

Effective transmission of hydraulic power. Transmit the power required for downhole power drilling tools the hydraulic power of the drill bit.

The weight of the drill pipe casing. The buoyancy effect of drilling fluid on drilling tools casing can reduce the load on the lifting system during the tripping process.

Provide a large amount of stratigraphic data, use drilling fluid, electrical logging, rock cuttings logging, other methods to obtain downhole data.

The hydraulic fracturing of rocks. The high-speed jet formed by the drilling fluid through the nozzle can directly break assist in breaking rocks.

water-base drilling fluids

Water-based drilling fluid is a sol-gel suspension mixed system with water as the dispersion medium, bentonite, weighing agent, various chemical treatment agents as the dispersion phase. Its main components are water, clay, weighing agents, various chemical treatment agents.

Water-based drilling fluids can also be divided into:

(1) Freshwater drilling fluid.

(2) Salt water drilling fluid (including seawater salt water drilling fluid).

(3) Calcium treated drilling fluid

(4) Saturated saline drilling fluid.

(5) Mixed emulsified (water in oil) drilling fluid

(6) Non dispersed low solid polymer drilling fluid.

(7) Potassium based drilling fluid.

(8) Polymer drilling fluid.

Oil-based Drilling Fluids

Petroleum continuous phase drilling fluid is a sol-gel suspension mixed system that uses crude oil crude oil as the dispersion medium weighting agent, chemical treatment agent, water as the dispersion phase. Its main components are crude oil, diesel, weighting agent, chemical treatment agent, water. It basically experienced crude oil drilling fluid, oil-based drilling fluid, oil-water (reverse phase lotion) drilling fluid.

(1) Crude oil drilling fluid.

(2) Oil based drilling fluid.

(3) Oil in water (demulsified) drilling fluid

Gas drilling fluid

Gas drilling fluid is a type of drilling fluid that uses air natural gas as the drilling fluid.

Foam drilling fluid is a kind of drilling fluid that uses foam as drilling fluid. Its main components are liquid, gas foam stabilizer.

Drilling fluid is generally divided into eight systems: non dispersed solid polymer drilling fluid, freshwater drilling fluid, saline drilling fluid, saturated saline drilling fluid, calcium treated drilling fluid, potassium based drilling fluid, oil-based drilling fluid, gas drilling fluid, etc.

Drilling fluid is the "blood" of drilling plays a very important role in drilling operations. Therefore, the requirements for drilling fluid are high, mainly in four aspects:

Drilling cycle requirements

The requirements for drilling fluid are low viscosity, strong sand carrying capacity, low static shear force, good lubrication performance, low friction. There are few solid particles.

Keep the wellbore stable.

Drilling achieves a balance between the use of drilling fluid pressure columns formation pressure through the formation, resulting in stable drilling fluid density; The density of drilling fluid is balanced by the pressure column of drilling fluid to balance oil gas pressure. Drilling fluid is necessary to overcome unstable formations.

Require drilling fluid to protect oil gas reservoirs

In order to prevent drilling fluid causing damage to oil gas reservoirs, it is required that the water loss of the drilling fluid be small. Thin mud cake (after the drilling fluid loses water, the drilling fluid forms a solid pressure difference in the wellbore solid particles form a mud cake ring), with low solid content low hydration degree of the filtrate (after the filtrate enters the formation).

key role

The harsh environment of underground drilling operations promotes the research development of drilling fluids, requiring the completion of the following key tasks during the drilling process: suspension, pressure control, rock stability, buoyancy, lubrication, cooling.