Classification of drilling mud

Drilling mud classification  Drilling mud additives

1. Requirements for drilling circulation

The requirements for drilling fluid in the drilling cycle are low pump pressure (low viscosity), strong sand carrying capacity (high dynamic shear force), low starting pump pressure (low static shear force), good lubrication performance, low friction, small wear (less solid particles).

2. To maintain wellbore stability

The drilled formation needs to be balanced with the pressure column of the drilling fluid the formation pressure, with a stable density of the drilling fluid; When drilling oil gas reservoirs, it is necessary to balance the pressure of oil gas by relying on the pressure column of the drilling fluid. The drilling fluid density is required to be appropriate. Require drilling fluid to have the ability to overcome unstable formations, such as wellbore shrinkage caused by mudstone water absorption expansion; Conglomerates volcanic rocks can cause cross collapse when encountering water, while salt rocks can form karst caves when encountering water, which requires drilling fluids with different properties.

3. Require drilling fluid to protect oil gas reservoirs

After drilling the oil gas layer, the drilling fluid comes into contact with the oil gas layer. In order to prevent the drilling fluid damaging the oil gas layer, it is required to have small water loss, thin mud cake (after the drilling fluid loses water, solid particles with solid pressure difference form a mud cake ring on the wellbore), low solid content, low hydration effect of the filtrate (chemical reaction between the filtrate the liquid in the formation after entering the formation).

4. Protecting the environment ecology

Drilling fluid often contains crude oil, diesel, various oils, a large amount of chemical treatment agents. To prevent the potential impact of drilling fluid on the environment ecology, it is required to use harmless non-toxic drilling fluid.

Mud has many functions, mainly carrying rock debris the bottom of the well to the surface. With the rapid progress of oilfield technology, drilling fluids have evolved only meeting the needs of drill bits to meeting various drilling needs.

1. Clean the bottom of the well, suspend carry rock debris, keep the wellbore clean.

2. Balance formation pressure, stabilize wellbore, prevent wellbore collapse, blowout, leakage.

3. Transmit water power to help drill bits break rocks.

4. Transfer power to downhole power drilling tools,

5. Cool down the drill bit drilling tools.

6. Use drilling fluid for geological gas logging.

7. Offshore oil drilling completion engineering, including geology, exploration, cementing, casing, logging, logging, all require the cooperation of mud to complete the operation.