Drilling fluid

Drilling fluid, commonly known as mud, is translated into drilling mud in English. It is recognized as the blood of oil field drilling and plays a very important role in drilling operations. Therefore, the drilling fluid is very demanding, mainly in four aspects:

1. Requirements for drilling cycle

Drilling fluid requirements for drilling fluid 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 and low wear (less solid particles) ).

2. To maintain the stability of the wellbore

The drilled formation should be balanced by the pressure column of the drilling fluid and the pressure of the formation. The density of the drilling fluid is stable. When drilling the oil and gas layer, the pressure column of the drilling fluid is used to balance the pressure of the oil and gas. The drilling fluid is required to overcome the performance of the unstable formation, such as the expansion of the wellbore caused by the swelling of the mudstone; the conglomerate and the volcanic rock collide with the water, and the salt rock forms a cave with water, which requires different drilling fluids.

3. Require drilling fluid to protect oil and gas layers

After drilling the oil and gas layer, the drilling fluid is in contact with the oil and gas layer. In order to prevent the drilling fluid from damaging the oil and gas layer, the drilling fluid is required to have small water loss and thin mud cake. After the drilling fluid loses water, the solid pressure difference solid particles form mud on the well wall. The cake ring), the solid phase content is low, and the hydration of the filtrate is low (the chemical action of the filtrate after entering the formation and the liquid in the formation).

4. Protect the environment and ecology

Drilling fluids often contain crude oil, diesel oil and various oils and contain a large amount of chemical treatment agents. To prevent the environmental and ecological effects of drilling fluids, it is required to use harmless and non-toxic drilling fluids.

Mud has many functions, mainly to carry cuttings from the bottom of the well to the ground. With the rapid advancement of oilfield science and technology, drilling fluids have evolved from just drilling drills to adapting to all aspects of drilling.

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

2. Balance formation pressure, stabilize wellbore, prevent well collapse, blowout, and lost circulation.

3. Pass water power to help the bit break the rock.

4. Passing power to the downhole power drill,

5. Cool the drill bit and the drill.

6. Drilling fluid is used for geological and gas logging.

7. Offshore oil drilling and completion projects, including geological, exploration, cementing, casing, logging, logging, etc., need to be completed by the cooperation of mud.