Mud, the scientific name is drilling fluid, English translation for drilling mud, is considered to be the blood of oil field drilling, plays a very important role in drilling homework. Therefore, the request for drilling fluid is very high, there are four main aspects:
1。 Request for drilling reincarnation
Drilling cycle request for drilling fluid is low pump pressure (low viscosity), strong sand carrying capacity (high dynamic shear force), low starting pump pressure (low static shear force), good smooth function, low friction and low wear (less solid particles) ).
2。 To maintain the fluctuation of the wellbore
The drilled formation should be balanced with the pressure column of the drilling fluid and the formation pressure, and the density of the drilling fluid fluctuates; 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, and the drilling fluid density is appropriate. The drilling fluid is requested to have the function of restraining the non-fluctuating formation, for example, the mudstone absorbs water and shrinks to form the wellbore expansion; the conglomerate and the volcanic rock form a collapse with water, and the salt rock forms a cave with water, that is, a drilling fluid having a divergent nature is requested.
3. Request drilling fluid to maintain the reservoir
After drilling the oil and gas layer, the drilling fluid is in contact with the oil and gas layer. In order to avoid damage to the oil and gas layer by the drilling fluid, the drilling fluid is required to have small water loss and thin mud cake. After the drilling fluid is dehydrated, the solid pressure difference solid particles form mud on the well wall. The cake ring), the solid phase content is low, and the hydration effect of the filtrate is low (the chemical influence of the liquid in the formation after the filtrate enters the celestial layer).
4. Maintenance and ecology
Drilling fluids often contain crude oil, diesel oil and various types of oils and contain a small amount of chemical treatment agents。 In order to avoid the impact of drilling fluids on the situation and ecology, it is required to use harmful and non-toxic drilling fluids。
Mud has many functions, and the second is to carry the cuttings from the bottom of the well to the air. Following the improvement of oilfield technology, drilling fluids have been drilled from just enough drills to meet the needs of drilling.