Installation of mud cleaner in drilling system
In drilling systems, mud cleaners are often co-located with the desilter. Desilter or hydrocyclone (mud cleaner) is usually used to treat unweighted drilling fluid mud. Drilling fluid vibrating screen is required to handle drilling fluid containing barite or hematite. The size of the solid phase filtered by the hydrocyclone is usually larger than that of barite, and the smaller size is returned to the drilling fluid together with the liquid phase. Tips for use, if barite is added, drilling fluid shaker should be used.
Another method of replacing the drilling fluid mud cleaner with a main drilling fluid shaker is commonly used in offshore drilling processes. Use a linear or translational elliptical drilling fluid shaker to process the fluid in the upper wellbore, and use less drilling fluid shaker to treat fluids with reduced wellbore size and increased drilling fluid mud density. Some adjustments are needed on site, and up to 20 4-inch hydrocyclones can be installed on the drilling fluid shaker. Feed and overflow of a hydrocyclone under normal conditions. In general, all the desilter removes the underflow of the non-weighted drilling fluid and is discarded, while the drilling fluid shaker processes the drilling fluid from the overflow pipe. This is usually the maximum flow rate. As the depth of the well continues to increase, heavier drilling fluids need to be used, at which time the flow rate will decrease. After adding barite, close the valve to prevent drilling fluid from flowing into the shaker. When the underflow of the desilter is transferred to the shaker, the drilling fluid shaker becomes a mud cleaner.
Operation of drilling fluid mud cleaner.
For the first time, a mud cleaner is used in a well site to handle heavy drilling fluids, and the mud cleaner should be turned off. Large amounts of barite are removed during the first cycle. In practice, this indicates that the drilling fluid mud tank is not installed vertically.
The drilling fluid mud gun draws back the drilling fluid from the addition or suction part to the removal tank. A large portion of API-compliant barite will still be removed by a 200-mesh screen (74 microns). If the barite can pass through the drill nozzle, the barite will be dispersed and not removed by the screen.
It is often heard that the aggravating drilling fluid initially passes through the mud cleaner and "all barite will be removed." Why is this so? The density of drilling fluid decreases, and it is necessary to add an extra normal amount of barite to maintain the density. When the solid phase (barite or drill cuttings are removed from the drilling fluid, the density of the drilling fluid will decrease. In fact, regardless of whether these relationships are drilling Swarf, barite, gold, silver, or diamond, removing all solid phases larger than 74 microns is very useful for reducing drilling accidents because these solid phases will form a dense mud cake, which will cause stuck drilling. Mud cleaner removal The solid phase situation is similar to the drilling fluid centrifuge processing of heavy drilling fluid or underflow. Although it seems that a lot of barite will be removed, tests have shown that this is not the case.
The API stipulates that 3% by weight of the barite can be greater than 74 microns. For 100,000 lbs of barite, 3,000 barites are filtered by API200 sieve. For this reason, drilling fluid mud in the feed compartment should not be circulated from the upper stream, and the main drilling fluid shaker will also remove most of the barite with a size larger than API200 mesh. The effect of barite is not obvious because the quality of the drilling fluid usually determines the amount of shaker screen removal.
The principle of removing the solid phase from drilling mud by a mud cleaner is similar to that of a solid phase separated by a drilling fluid centrifuge. The solid phase concentration is about 60% and the liquid is about 40%. In the beginning, large amounts of liquid seemed unreasonable. Researchers frequently take sand to check the oil recovery process under various conditions. If the gap of the sand cylinder reaches 33% ~ 35%, the sand cylinder is very tight. Such as sand on the beach, when the tide recedes, they are 40% water, and they can form a dune without drainage. The drilling fluid mud passing through the drilling fluid mud cleaner screen contains the same liquid volume percentage as the mud water from the drilling fluid centrifuge underflow.
Mud cleaners can continuously process drilling fluids just like drilling fluid shakers. The screen of the mud cleaner can prevent larger cuttings particles from entering the drilling fluid system. Occasionally stopping the mud cleaner can also keep the solid phase in the drilling fluid system. When these larger solid phases are ground to smaller sizes, it is more difficult to remove. A drilling fluid centrifuge can remove smaller solid phases from the weighted drilling fluid, but it cannot handle all drilling fluids. If a slurry cleaner is used continuously, the solid phase can be removed before the larger solid phase is ground.
Note again that drilling fluid mud cleaners and drilling fluid centrifuges are complementary and not mutually exclusive. Mud cleaners are used to remove solid phases that are larger than barite, and drilling fluid centrifuges are used to remove those smaller than barite.
Other uses of mud cleaners
Additional uses of mud cleaners are for tunneling, non-excavation and shield engineering. . The sites of these projects are mainly below roads, at the bottom of lakes or rivers, etc., and are used as gas pipelines, fiber optic cable channels, or other installation sites for circulating drilling fluids. Mud configuration and handling is often a tricky issue in these projects. Therefore, for these small drilling systems, a mud cleaner is installed on the first mud tank of the circulation system. The screen of the mud cleaner removes the solid phase, and the remaining drilling fluid mud is returned to the mud tank. The size of the screen and the diameter of the wire used here are larger than those used in the drilling of oil fields. The purpose of using these screens is to remove water from the cuttings and return as much liquid phase as possible to the drilling fluid mud. The solids produced by these engineering excavations are less destructive than the solids produced in oilfield drilling compared to drilling fluid muds. Therefore, the opening sizes of these screens in mud cleaners are larger than those used in oilfield drilling Size of the opening.