Maximum effect of mud cleaner

The main function of the mud cleaner is to remove solid-phase materials with a larger particle size than barite in the drilling fluid. If there is enough drilling fluid to bypass the drilling fluid shaker, the API200 mesh (74 μm) screen of the mud cleaner can remove a large amount of solid phase from the weighted drilling fluid. If API200 mesh drilling fluid shaker can be used to treat drilling fluid, the usage rate of mud cleaner will decrease quickly. However, whenever it is used, the mud cleaner can remove the solid phase downstream. The larger solid phase that bypasses the drilling fluid vibrating screen can easily block the sand remover. This situation is very common on the site, but usually someone special cleans the sand remover to prevent blockage.
These larger solid-phase particles may enter the drilling fluid through a notch on the screen or some other places. Among them, the most likely place is the drilling fluid tank of the drilling fluid vibrating screen. Before drilling, in order to prevent drilling fluid from blocking the vibrating screen, the derrick is responsible for cleaning the screen. The procedure usually includes: opening the bypass valve of the drilling fluid vibrating screen, and quickly pouring solid particles into the tank under the drilling fluid vibrating screen. We often call it a grit chamber or a sedimentation tank, but not all large solid Phase particles can settle in the tank, and when the cycle is re-established, the hydrocyclone will still block. Another method that causes large particles of solid phase to flow under the drilling fluid shaker is to pour the drilling fluid from the supply tank directly into the compartment below the shaker. Also, the solid phase is not sedimentation but plugs the sand remover. When the solid phase blocks the outlet of the sand remover, the sand remover cannot remove the solid phase, and the efficiency of removing the solid phase is correspondingly reduced. If more than half of the hydrocyclone is blocked, the solid control system will be severely affected.
The second use of mud cleaners is to remove a portion of the solid phase in expensive non-weighted drilling fluids, such as the solid phase in potassium chloride drilling fluids. In this case, the solid phase with a size larger than the screen hole is removed by the underflow of the desilter, while the smaller solid phase and liquid are retained in the drilling fluid system by the drilling fluid shaker. This method is also effective for non-water-based drilling fluids and seawater-based drilling fluids.
In non-weighted drilling fluid systems, the underflow of the desilter can reach the drilling fluid tank directly. The drilling fluid centrifuge can remove the larger solid phase, while the smaller solid phase and most of the liquid remain in the drilling fluid system. This method is very convenient if a drilling fluid centrifuge is available at the wellsite. Most of the solid phase can pass through the mud cleaner, but it is not easy to pass through the drilling fluid centrifuge. However, it is not economical to rent a drilling fluid centrifuge for this purpose. Both technologies are widely used in the field.
The high cost of the liquid phase has prompted people to find ways to recycle it as much as possible. However, the liquid phase, whether through a drilling fluid centrifuge or a mud cleaner, always contains some smaller volume of solid phase. In some wells, these solid phases do not affect drilling speed or increase drilling costs. In general, the impact of cuttings on drilling costs in heavy drilling fluids is much greater than in non-heavy drilling fluids. In non-weighted drilling fluids, the density of drilling fluids can be controlled between 8.8 and 8.9 lb / gal by appropriate methods. For poor solid-phase control, it is impossible to control the density below 9.5-10 lb / gal due to equipment and operation problems. Below 10,000 ft, a difference in density of 1 lb / gal will cause a difference in bottomhole pressure of 520 psi. This will reduce the drilling speed due to the hold-up effect and the slight increase in rock, and it will also affect the cleanliness of the wellbore. For non-heavy drilling fluids, due to solid phase removal, the density decreases and the plastic viscosity decreases from 12 cP to 6 cP. For wells with a suction value of 10 lb / 100 ft ^ 2, this will increase the apparent viscosity from 224 cP to 466 cP. It means that the wellbore will be significantly improved. Good solid-phase control requires the ability to generate large cuttings and bring them to the surface without affecting the performance of the drilling fluid.
Usually, most of the mud cleaner removes barite. This indicates that most of the cuttings are dispersed into the drilling fluid. When drilling into the smectite formation with clear water, the solid phase dispersed in the drilling fluid is mostly small particles. This indicates that the drilling fluid is very inhibitive. Generally, the mud cleaner should be turned off and a drilling fluid centrifuge is used to remove these smaller particles.
From non-heavy drilling fluids to heavy drilling fluids, most operations are very expensive and difficult. Recycling the liquid phase method to save the liquid phase and remove the solid phase will save costs, but it may also affect the final drilling cost because it directly affects the cost of processing in many cases. Due to problems caused by improper solid phase control, it is obvious that the cost increase or drilling failure is caused. The poor performance of non-heavy drilling fluids leads to increased drilling costs, which are more sensitive and less visible during operation. For these reasons, the solid-phase control of heavy drilling fluids is more direct than the solid-phase control of non-heavy drilling fluids.
The use of an assessment of total drilling costs can avoid common mistakes. For example, it is easy to calculate the replacement of barite powder with drill cuttings. If drilling cuttings are allowed to accumulate and reach the density of drilling fluid, the cost of barite can be saved, and the density of drilling fluid can reach 11 lb / gal. The amount of barite saved can be easily calculated. Even at 5 cents per pound of barite, the cost savings are considerable. However, this leads to an increase in the total cost of drilling. Looking back at the problems mentioned earlier due to the inability to remove the solid phase, it is foreseeable that many problems will be encountered in the future when the solid phase treatment of drilling fluid is increased.

Mud cleaner