In order to effectively restore the density of drilling fluid, the most effective means is using a vacuum degasser . Here is the working process of the vacuum degasser.
Annular drilling fluid density is reduced which can lead to reduce of static fluid column pressure. This may cause malignant blowout accidents, borehole collapse, etc. So the vacuum degasser is a necessary machine.
The degasser commonly uses vacuum mission pump . There are two main reasons for this. One is that the mud in the tank is sucked to the top of the degasser and makes it form a thin layer of liquid on the damper, cone or funnel. The other is that the degasser tank releases gas and air. Vacuum pump can produce a kind of pressure to remove the gas through a thin gas pipeline row.
According to Henry's law, the solubility of gas in water is related to water temperature and water pressure. Under a certain temperature, the solubility is proportional to the gas pressure. Under certain pressure, when the water temperature reduces, the solubility of a gas increases. On the other hand, when the water temperature increases, the gas solubility will decrease. When the water pressure reduces, the machine will be under lower water temperature. The gas is gradually dissolved in the water, thus we should remove the gas in the water. Vacuum design will help release the free gas and dissolved gas in the water, and then the degassing is after water injection system through the automatic exhaust valve system. The low air content in the water is not saturated. The degasser can quickly absorb gas, so as to achieve water balance. And the vacuum degasser can repeat the cycle in 20 ~ 30 seconds. Cycling can remove all gas in the system in fact.
What is going on after one or two minute of vacuum degasser work with degasser tank? Import pipeline and export pipeline will be sucked by mud at the same height. When the mud in the inlet pipe rises and begins to flow into the top slot and before the vacuum tank, the mud slurry surface will raise. The floating ball valves open the vacuum tube line to prevent further increase of vacuum degree. So you must ensure that when starting the vacuum pumps, at the same time, you should start the jet pump. So jet pump can keep the vacuum tank mud slurry surface is lower and the floating ball is in the proper position. This can keep the vacuum pump and degassing interlinked. Besides, this tank vacuum degree can increase enough from import pipeline suction to the top.
What is very important is that you should make sure that the floating ball is always working in order to prevent the mud slurry tank surface from rising through the pipe into the vacuum pump. The vacuum tube line is equipped with dehydrator and it is often used to collect heat with the mud at the bottom of the water vapor. And the degasser can put the water out. In the upper part of the dehydrator is equipped with floating ball valve. If the water vapor condensation or vacuum high level makes the mud into the dehydrator, floating ball will shut down the channel to the vacuum pump. When the upper part of the dehydrator causes valve leakage and makes the mud into the vacuum pump, the cylinder, piston ring and bearing will be grinding. As these occur, you should clean the vacuum pump parts. If the valve is open, the mud will be through the pipe damaging the valve and piston. The mud in the crankcase will result in higher oil level. The float valve will have a sign of failure.