Technical solutions for reducing solid residue in mud shale shakers

As equipment in oilfield drilling fluid solids control systems, mud shale shakers can suffer from problems such as screen clogging, reduced processing efficiency, and drilling fluid waste due to solid residue. Based on the structural design of TR solids control shale shakers (e.g., double-layer, translational elliptical, high-frequency linear shale shaker), the following provides practical solutions covering equipment selection, parameter adjustment, maintenance, and auxiliary systems.

I. Screen Optimization and Selection: Reducing Retention at the Source

1. Matching shaker screens material and aperture

   Select a screen with the appropriate mesh size based on the characteristics of solid particles in the drilling fluid (particle size distribution, hardness):

   Coarse particles (>74μm): Use 100-150 mesh woven screen (TR stainless steel mesh is recommended, with an opening rate ≥75%) to avoid large particles accumulating due to excessively small pore size;

   Fine particles (20-74μm): Use 200-325 mesh polyurethane screen or composite screen (with stronger wear resistance and anti-clogging properties). Prioritize double-layer screens with "coarse top and fine bottom". The upper layer intercepts coarse particles, while the lower layer filters fine particles, reducing the load on a single-layer screen.

   Special working conditions (such as those containing clay particles or salt crystals): Use screens with anti-stick coatings to reduce the adhesion between particles and the screen.

2. Optimize screen installation and tension

   During installation, ensure the screen is flat and the edges are pressed tightly against the screen frame without gaps (TR equipment is equipped with a quick tensioning device; tighten the bolts according to the operating procedures) to prevent the screen from loosening and causing particles to get stuck in the gaps;

   Regularly check the screen tension. Insufficient tension will reduce the screen vibration amplitude and prevent particles from bouncing effectively. The tensioning mechanism needs to be adjusted in time.

II. Precise adjustment of vibration parameters: improving particle separation efficiency

1. Frequency and amplitude adaptation adjustment

   TR shale shakers use variable frequency motors (frequency range 50-60Hz, amplitude adjustable from 0-5mm), which are adjusted according to the drilling fluid viscosity and solid content.

   High-viscosity drilling fluid (>50mPa·s): Increase vibration frequency (55-60Hz) + reduce amplitude (2-3mm) to enhance screen vibration intensity and break particle adhesion;

   High solids content (>15%): Reduce frequency (50-55Hz) + increase amplitude (3-5mm) to improve particle bounce and prevent accumulation on the screen surface;

   Elliptical shale shaker: Adjust the screen inclination angle. Increase the inclination angle at the feed end (6-8°) to accelerate the downward movement of coarse particles, and decrease the inclination angle at the discharge end (3-5°) to ensure thorough filtration of fine particles.

2. Vibration direction and phase angle optimization

   Linear shale shaker: Adjust the phase angle of the vibrating motor so that the vibration direction of the screen forms a 30-45° angle with the material flow direction, which promotes uniform sliding of particles along the screen surface and avoids local stagnation;

   Double-layer shale shaker: Ensures synchronous vibration of the upper and lower screens (TR equipment uses synchronous belt drive), with the lower screen vibrating at a slightly higher frequency than the upper screen (difference of 5-10Hz) to prevent particles falling from the upper screen from accumulating in the lower screen.

III. Feeding System Optimization: Avoiding Local Overload and Stagnation

1. Uniform fabric design

   Install TR's special feeder (such as spiral or diffuser type) to ensure that the drilling fluid is evenly distributed across the entire width of the screen from the feed inlet, avoiding local screen overload and blockage caused by single-point feeding.

   Control the feed flow rate: Adjust the feed pump discharge rate according to the rated capacity of the shale shaker (TR TRZS series capacity 50-200m³/h) to avoid over-flow feeding (it is recommended that the feed rate not exceed 85% of the rated value) to prevent drilling fluid from forming a "liquid pool" on the screen surface and causing particle sedimentation and retention.

2. Drilling fluid pretreatment aid

   Before feeding, the material is pre-treated by a desander and a desilter: large particles (>200μm) are removed first, and the load on the shale shaker is reduced (especially suitable for deep wells and drilling in complex formations).

   Adjusting drilling fluid viscosity: If the viscosity is too high (>60mPa・s), an appropriate amount of diluent can be added to reduce particle agglomeration and facilitate separation by screen.

IV. Routine Equipment Maintenance: Reducing Potential Risks of Delays

1. Clean the screen regularly

   After each shift, use a high-pressure water gun (pressure 0.3-0.5MPa) to rinse the screen (rinse from bottom to top to avoid particles getting stuck in the holes), focusing on cleaning the edges, corners and other areas where particles are prone to get stuck.

   If local blockage occurs, use a soft brush to clean it (do not use hard tools to scrape the screen to avoid damaging the screen aperture). If necessary, disassemble the screen for thorough cleaning.

2. Check the operating status of core components

   Vibration motor: Regularly check the wear of the motor mounting bolts and eccentric blocks to ensure stable vibration output (eccentric block misalignment will cause uneven vibration and local particle retention), and add lubricating oil regularly (it is recommended to replace it every 500 hours).

   Screen frame and shock absorber springs: Check the screen frame for deformation and the shock absorber springs for aging (decreased spring elasticity will weaken the vibration effect). Replace damaged parts in time (TR provides original parts to ensure equipment compatibility).

   Seals: Inspect the sealing strips on the edge of the screen frame to prevent drilling fluid leakage that could cause solid particles to accumulate at the bottom of the equipment. Replace worn seals regularly.

3. Create maintenance table

   Record the screen replacement cycle (generally 500-800 hours, adjusted according to working conditions), vibration parameter adjustment records, cleaning frequency, etc., to form a standardized maintenance process and avoid the accumulation of problems due to untimely maintenance.

V. Auxiliary System Upgrade: Enhanced Anti-Stuck Effect

1. Install ultrasonic anti-blocking device

   For applications involving fine mesh screens (>200 mesh) or a high concentration of sticky particles, the TR ultrasonic anti-clogging system can be installed. This system uses ultrasonic vibration (frequency 20-40kHz) to cause the screen to vibrate slightly, preventing particles from adhering to the surface of the pores and reducing clogging by more than 30%.

2. Optimize the design of the slag discharge channel

   Check if the slag discharge port of the shale shaker is unobstructed, ensure that the angle of the slag discharge plate is reasonable, and avoid the accumulation of solid particles at the slag discharge port. If necessary, install a scraper device (TR can provide customized slag discharge auxiliary accessories) to accelerate the discharge of waste residue.

3. Negative pressure assist system (optional)

   For drilling fluids with high fine particle content, a negative pressure device can be installed: by creating a slight negative pressure under the screen, the drilling fluid passes through the screen more quickly, while reducing the residence time of particles on the screen surface and lowering the probability of retention.

The core logic for reducing solids retention in mud shale shakers is: "Source adaptation (shaker screen + parameters) + process optimization (feeding + operation) + post-maintenance (cleaning + components)". Combining the high-frequency vibration and high-efficiency screening design of TR solids control shale shakers, the above solutions can significantly reduce solids retention rates, improve equipment processing efficiency (it is recommended to regularly test screen penetration rate, with a target value ≥85%), extend screen lifespan, and reduce drilling fluid losses and equipment maintenance costs.

For customized solutions for specific equipment models (such as TRZS series linear shale shakers and TRBS series translational elliptical shale shakers), please contact the TR Solid Control technical team for one-on-one technical support.