There are still have some chance of problems appeared when drilling cuttings met shale shaker which occur on the process of drilling. Here is the solutions.
Cuttings have tendency to move to one side of shale shaker – this situation happens because of unlevel installation, worn out isolation spring, improper maintenance. The solution is to level the shale shaker, replace some worn part with correct spare parts from the original manufacture.
Polymer coating screens – some polymers especially long chain type added into water based mud most likely coat fine screen mesh. The simple solution is to screen down (use bigger screen size). Additionally, if you use multi-layer screen, you may need to less screen layers to minimize polymer coating issue.
hydrated cuttings – sticky hydrated cuttings can plug up the shale shaker screens, causing loss of mud over the shakers. The solutions include getting water based mud chemistry correct to prevent shale hydration or to use oil based mud.
Some shale types react strongly with water based mud. This causes the shale to hydrate and swell; shale cuttings in the well become sticky so clump together, or can stick to the steel drillstring downhole, closing up the annulus and causing swabbing and stuck pipe.
Inflow rate of drilling fluids are over the shale shaker’s processing capacity will also make shale shaker screen jammed.User can adjust its deck angle,or reduce the inflow of mud fluids to solve the problem.
The motion of vibrator motor are not horizontal in linear mode shale shaker. Under such circumstances,user should check the motion of eccentric block inside of vibrator motor.
Lost circulation material blinding screens – when the LCM is utilized, you may see that screens are plugged by the LCM and mud is over flow at the shale shaker. The simple solution is to “screen down” (increase size of opening) so the LCM can pass through the screen. Moreover, there is another complex method. You select the LCM which has less density than base fluid and use bigger screen size to let the LCM passing through. Then, you send the mud after shale shakes to hydrocyclones so that the LCM can be recovered for re-use. You can have the mud after hydrocyclone goes to the fine screen to remove some drill solid as well.
Overhigh working temperature of will short shale shaker screen‘s life. The recommended highest working temperature of mud is less than 40° when it being used in field or in house. Especially in hot weather, There should have an awning above the shale shakers.
High viscosity of drilling fluids will make shale shaker screen mesh plug up. If this happens, you need to change bigger size of screen or add chemical materials to attenuate the viscosity.