How to solve problem of drilling fluid leakage in shale shakers?

During drilling operations, common problem arises where drilling fluid leaks from the shale shaker, meaning the drilling fluid overflows directly from the screen surface without being filtered. This type of malfunction frequently occurs at oil drilling sites.

"Drilling fluid leakage" is common fault in drilling operations. It refers to the drilling fluid overflowing, leaking, or being lost through the screen without being effectively separated from the solid phase. This not only affects the performance of the drilling fluid but also causes material waste and environmental problems.

This section analyzes the troubleshooting of screens, vibration parameters, equipment status, drilling fluid characteristics, etc., and provides a systematic solution by combining the structural design of TR Solids Control shale shakers (such as the TRZS series) (such as dual-motor excitation, rapid screen tensioning, adjustable phase angle, etc.).

I. Emergency Response: Stop the leak first, then quickly resume operations.

1. Reduce feed rate / Stop feeding

   Immediately notify the drilling pump unit to reduce the discharge rate or temporarily close the feed valve to avoid large amounts of drilling fluid overflowing, causing waste and environmental pollution. At the same time, clean the residual drilling fluid on the screen surface to prevent accumulation and exacerbation of the malfunction.

2. Temporary adjustment of vibration parameters

   If the equipment supports frequency conversion adjustment, appropriately increase the vibration frequency (TR Solid Control shale shaker common frequency range: 50-60Hz) to enhance the screen penetration;

   Check if the amplitude is too small (normal amplitude is 1.5-3mm). The amplitude can be increased by adjusting the angle of the eccentric block (power must be turned off to avoid injury).

3. Emergency replacement of spare shaker screen

   If shaker screen is obviously damaged or the edges are detached, replace it with spare screen of the same model (TR Solid Control shale shaker commonly uses 100-200 mesh screens, made of stainless steel wedge screen or polyurethane screen). When replacing, ensure that the edges of the screen are pressed tightly against the screen frame without gaps.

II. Precise Investigation: Identifying Root Causes by Prioritization

(a) Screen-related problems (most common, accounting for 80% of failures)

(b) Vibration system failure

1. Abnormal amplitude/frequency: Inconsistent eccentric block angle, abnormal motor speed, belt slippage;

   Solution: ① Adjust the angle of the eccentric blocks on both sides to be consistent (TR Solid Control Equipment recommends an angle of 30°-60°, the larger the angle, the greater the amplitude); ② Check the motor speed (standard speed: 1480r/min). If the speed is insufficient, check the power supply voltage or motor fault; ③ Replace the loose belt and adjust the belt tension.

2. Vibration direction deviation: loose vibrator fixing bolts, deformed screen box;

   Solution: ① Tighten the vibrator base bolts (torque value: M16 bolt 45-55 N·m); ② Check if the screen box is level, and correct it with a level (level error ≤ 0.5 mm/m).

(c) Equipment Structure and Installation Issues

1. Screen box tilting: The horizontality was not up to standard during installation, and the height of the shock absorbers was inconsistent.

   Solution: Adjust the height of the shock absorber (TR Solid Control parts model: TR-ZS-JZ-002) to ensure the screen surface is level, with the feed end slightly lower than the discharge end (inclination angle 3°-5° to facilitate drilling fluid flow).

2. Damaged shock absorbers: The shock absorbers are aging or leaking oil, resulting in poor vibration transmission;

   Solution: Replace the damaged shock absorber and ensure that all four shock absorbers are of the same model and that the force is distributed evenly.

3. Improper feed inlet position: The feed inlet is directly facing a certain point on the screen, resulting in excessive impact force and causing drilling fluid to splash.

   Solution: Adjust the angle of the feed pipe and install a guide plate to ensure that the drilling fluid is evenly distributed in the width direction of the screen (the guide plate height is recommended to be 5-8cm).

(d) Drilling fluid properties

1. Excessive drilling fluid viscosity/shear force: Excessive bentonite addition or improper treatment agent ratio leads to poor drilling fluid fluidity;

   Solutions: ① Add diluent (such as tannic acid or iron-chromium salt) to reduce viscosity (control apparent viscosity: 15-30 mPa·s); ② Strengthen drilling fluid agitation to prevent solid particles from settling.

2. Excessive sand content in drilling fluid: The upstream solids control equipment (such as vacuum degasser and desander) is not working properly;

   Solution: Check the operating status of the upstream equipment to ensure that the desander has separation efficiency of ≥95% (separation particle size ≥40μm) and prevent a large amount of coarse sand from directly entering the shale shaker.

III. Preventive Measures: Reduce Fault Recurrence

1. Routine maintenance

   Check the condition of the screen every shift, clean up surface debris in timely manner, and prevent hard objects from hitting the screen.

   Check the vibrator lubricating oil level weekly (it is recommended to use 32# anti-wear hydraulic oil, with the oil level at the center line of the oil window), and change the lubricating oil monthly;

   Regularly calibrate vibration parameters to ensure that the amplitude and frequency meet the requirements of drilling conditions.

2. Working condition adaptation

   Select the appropriate screen material based on the type of drilling fluid (water-based or oil-based). (For oil-based drilling fluids, polyurethane screens are recommended as they are more oil-resistant.)

   If the sand content suddenly increases during drilling, adjust the drilling parameters in time or activate the backup shale shaker to avoid overloading a single piece of equipment.

3. Personnel training

   Operators must be familiar with the equipment structure and master the standard procedures for screen replacement and parameter adjustment;

   Develop contingency plans to ensure a rapid response in the event of liquid leakage and minimize downtime.

To address drilling fluid leakage issues caused by shale shakers, first troubleshoot easily manageable factors (shaker screen, parameters), then address more complex factors (mechanical malfunctions, drilling fluid properties). In daily operations, standardizing screen selection and maintenance, regulating vibration parameters, and stabilizing drilling fluid properties can significantly reduce the failure rate.

TR Solids Control Technology provides precise guidance on equipment models, operating parameters, and fault videos. It can customize vibration screen parameter optimization schemes according to drilling conditions and quickly respond to fault repair needs.