Tank and tank installation for desilter and drilling fluid sand remover
Release time: 2015/12/10 Ai Yi NewsViews : 1481
When the desilter and drilling fluid sand remover are installed, the centrifugal cone of the larger size cyclone is placed upstream of the smaller size centrifugal tank, and each device of different size has its own separation tank. In general, desilter and drilling fluid desilter feed inlets can be used as part of drilling equipment. Cyclones should independently handle all drilling fluids entering their suction chambers. The suction part is immediately sent from the separation tank to the upstream of the discharge tank. The number of centrifugal cones can handle at least 100% of the drilling fluid, but preferably more than 100% of the drilling fluid enters the cyclone suction tank. A return flow of at least 100 gal / min between the cyclone discharge of the desilter and drilling fluid sand remover and the suction chamber usually ensures adequate treatment. If the pipeline arrangement is unreasonable, estimates based on drilling cycle rates will usually not meet the requirements. For example, if a 500 gal / min cyclone overflow returns to the suction chamber and a 400 gal / micron drilling flow enters the suction chamber, even if more fluid is processed than pumped downhole, it will not be treated sufficiently. In this case, the flow rate into the cyclone suction chamber is 900 gal / micron in. The drilling fluid treatment fraction is 500/900 or 56%. See Figure 1 for the installation of a reasonable mud remover and drilling fluid sand remover.
Drilling fluid sand remover
The drilling fluid sand remover device is used to separate drill cuttings in the range of 50 to 80 microns and barite in the range of 30 to 50 microns. When the drilling fluid shaker cannot be installed with API 140 mesh screen (100 microns) or finer, the drilling fluid sand remover can only be used to handle unweighted drilling fluid. They were originally used to remove high solids from fast drilling of large diameter upper boreholes. In water-based drilling fluids, the separation point produced by the drilling fluid sand remover is 50 to 80 microns and the density is 2.6 g / c microns ^ 3. Sand and larger particles are removed by a sand remover after passing through a drilling fluid shaker.
The drilling fluid sand remover is installed directly downstream of the drilling fluid shaker and vacuum degasser, and is directly sucked from the upstream tank, which is generally the discharge tank of the vacuum degasser. Emissions from the drilling fluid de-sander go directly to the downstream tank. The suction and discharge tanks are balanced through valves and openings at the bottom of each tank.
The drilling fluid sand remover is used uninterruptedly when drilling surface sections. After starting to drill, a manifold can be installed to handle all the total surface tank usage. After barite and expensive polymers are added to drilling fluids, drilling fluid sanders are generally not used because drilling fluid sanders can remove most of them. Oil-based drilling fluids are generally not treated with drilling fluid sanders because larger centrifuge cones expel a large amount of liquid phase.
The centrifugal cone of the desilter has a variety of sizes, 2 to 6 inches, which can separate 12 to 40 micron-level drill cuttings, and can also separate 8-25 micron-level barite particles. The desilter is installed downstream of the drilling fluid shaker, settling tank, vacuum deaerator and drilling fluid desilter. The centrifugal cone of the desilter is just different in size from the drilling fluid sand remover and works exactly the same. Common desilter centrifugal cone sizes are between 2 and 5 inches. A dedicated centrifugal sand pump should be used to feed the desilter.
It is not a good idea to run multiple parallel devices with one sand pump. If you do this, you need to choose between performance and corrective action opportunities. These devices enable the finest particle separation of any fluid-drill cuttings as small as 12 microns. Therefore, the desilter is one of the most important equipment for reducing the average particle size and cuttings.
The suction part of the desilter is also directly installed in the upstream mud tank, which is usually the discharge mud tank of the drilling fluid sand remover. The desilter suction and discharge tanks are controlled by one or more valves, or an opening at the bottom of each tank is balanced. The size of the valve or opening should be: diameter = √Q (gal / min) / 15. Q is the maximum expected flow and not the return flow. When this equipment is not working and the total rig flow has to pass through a valve or opening, the expected flow will double. Inhaled fluid will not enter the mud tank from the mud tank into the mud tank containing chemicals and other substances (barite and bentonite), because this may lose valuable treatment agents.
3. Operation comparison of drilling fluid sand remover and desilter
The function of the drilling fluid sand remover is to reduce the load of the downstream mud remover. Installing a drilling fluid sand remover in front of the mud remover effectively removes a large number of particles in the load of the mud remover and improves the efficiency of the mud remover. High drilling speeds, especially when using the largest diameter drill bits in loose, shallow well sections, can generate a lot of cuttings. This may cause "rope-like" emissions. Therefore, it is necessary to install a drilling fluid sand remover upstream of the mud remover. At this time, it has a larger volume capacity and can separate coarse cuttings. Drilling fluid sand removers remove large solids (such as coarse cuttings) from high-concentration solid phases. Only the desilter can effectively deal with the overflow on the drilling fluid sand remover which has reduced the solid phase content.
If the drilling speed is slow, generally, when there are only a few hundred pounds of drill cuttings per hour, the drilling fluid desilter can be turned off. The desilter can usually handle all circulating drilling fluid.
Desilter should be used for all non-weighted water-based drilling fluids. These devices are not used to aggravate drilling fluids because they can remove large amounts of barite. Most barite particles are in the silt-grain class. For all non-weighted fluids, the work of applying a desilter is important. However, in viscous oil-based drilling fluids (as seen in deepwater drilling), the bottom effluent can be recovered by centrifugation to recover the oil phase.
4.Problem of slurry inlet pipe head of cyclone in drilling fluid sand remover and mud remover
The feed lines of the cyclone of the desilter and drilling fluid sand remover cannot be installed horizontally. Centrifugal force will force the particles out of the elbow, which may overload some centrifugal cones, causing solid particles to bypass other centrifugal cones. It is a good idea to install a straight tube with a diameter of 1/3 in front of the centrifuge cone. This allows the particles and liquid phase to have time to remix and homogenize.