1. Drilling cycle requirements
Drilling cycle requirements for drilling fluids 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, low wear (small solid particles) ).
2. To maintain the stability of the wellbore
Drilled through the formation to use the drilling fluid pressure column and formation pressure balance, drilling fluid density is stable; drilling oil and gas layer to rely on drilling fluid pressure column to balance the pressure of oil and gas requirements Drilling fluid density appropriate drilling fluid to overcome instability The performance of the formation, such as the expansion of the muddy water that causes the wellbore shrinkage; the conglomerate, the volcanic rock that causes water to collapse, the salt rock that meets the water to form a cavern, etc., require drilling fluids with different properties.
3 requires drilling fluid to protect the reservoir
After drilling the reservoir, the drilling fluid is in contact with the reservoir. To prevent the fluid from damaging the reservoir, the drilling fluid needs to be low in water loss and the mud cake is thin (after the drilling fluid loses water, the solid pressure difference solid particles form mud on the well wall. Cake ring), low solid content, low hydration of the filtrate (chemical interaction of the filtrate with the fluid in the formation after entering the formation), etc.
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. In order to prevent the influence of drilling fluids on the environment and ecology, it is required to use non-hazardous, non-toxic drilling fluids.
The function of mud is many, mainly to carry the cuttings from the bottom of the well to the ground. With the rapid advancement of oilfield science and technology, drilling fluids have only met the requirements of drill bit drilling to adapt to all aspects of drilling.
1. Clean the bottom of the well, suspend the debris, and keep the wellbore clean.
2. Balance formation pressure, stabilize the wellbore wall, prevent well collapse, blowout, and well leakage.
3. Pass the water power to help the drill bit break the rock.
4. Transmit power for downhole power drills,
5. Cool the drill bit and drill tool.
6. Use drilling fluid for geology and gas logging.
7. Offshore oil drilling and completion projects, including geology, exploration, cementing, casing, logging, logging, etc., need to be completed through the cooperation of mud.