In drilling operations, the solids control system is a core component ensuring stable drilling fluid performance, extending equipment lifespan, and improving drilling efficiency. Its operational status directly affects the continuity and quality of drilling fluid circulation, thus impacting the overall safety and economy of the operation. However, solids control systems involve multiple stages of equipment, including vibrating screens, desanders, desilters, and centrifuges. Therefore, quickly determining whether these systems are operating normally is a crucial skill for field technicians.
Real-time Monitoring of Equipment Operating Parameters
Core equipment in the solids control system (such as vibrating screens and centrifuges) is typically equipped with parameter monitoring instruments. Real-time data allows for rapid identification of anomalies. For example: Vibrating screen parameters: Check if the screen amplitude is within the rated range (usually 3-8 mm) and if the vibration frequency is stable (commonly 1200-1800 times/minute). If the amplitude is too small, it may lead to incomplete solid-phase separation; if the amplitude is too large, it may accelerate screen wear.
Centrifuge Parameters: Observe whether the differential speed matches the design value (usually 5-30 rpm) and whether the separation factor meets the standard (the separation factor range varies depending on the centrifuge model). Abnormal differential speed may prevent effective solid phase discharge, while insufficient separation factor will affect the removal of fine particles.
Flow Rate and Pressure: Monitor whether the flow rate and pressure of the pumping system are stable. A sudden drop in flow rate may indicate pipeline blockage or pump failure; excessive pressure fluctuations may reflect internal wear or seal failure.
By comparing real-time data with equipment nameplate parameters or historical operating records, potential problems can be quickly located. For example, if the centrifuge differential speed is consistently lower than the set value, the motor or transmission system may need to be checked.
Visual Identification of Equipment Status
On-site observation is the most direct method to determine the operating status of the solids control system. The following details should be given special attention:
Equipment Appearance: Check whether there are any leaks of liquid or air from the equipment casing, and whether the seals are aged or cracked. For example, if drilling fluid leaks at the desander cone connection, it may indicate a damaged seal.
Solid Phase Discharge: Observe whether sand is continuously discharged from each equipment’s discharge port. If the vibrating screen discharges sand intermittently, it may be due to screen blockage or vibrator malfunction. If the centrifuge discharges sand suddenly, it may be due to abnormal differential speed or wear on the screw conveyor.
Liquid Level Changes: Check if the liquid level in the storage tank is stable. If the liquid level continues to drop, it may be due to insufficient processing capacity of the solids control system leading to drilling fluid loss. Excessive liquid level fluctuations may reflect instability in the pumping system.
For example, a drilling team found that the sand discharge from the desilter’s discharge port suddenly decreased. Inspection revealed severe wear on the screw conveyor blades, preventing normal solid phase discharge. Replacing the blades restored operation.
Sound and Vibration Analysis
Solids control equipment will produce specific sound and vibration patterns during operation. Abnormal signals often indicate malfunctions:
Abnormal Noise: If the vibrating screen makes a ‘clicking’ sound, it may be due to a loose screen or damaged vibrator bearings. If the centrifuge makes a sharp friction sound, it may be due to the screw conveyor contacting the inner wall of the drum.
Abnormal Vibration: Touch the equipment casing. If the vibration frequency does not match the rated value (e.g., the vibrating screen frequency is too low), it may be due to motor failure or a loose drive belt. If the centrifuge vibrates violently, it may be due to impaired drum balance or a loose foundation.
Temperature Monitoring: Check the temperature of key components such as the motor and bearings using an infrared thermometer. If the bearing temperature exceeds 80℃, it may be due to insufficient lubrication or overload operation, requiring immediate shutdown and inspection.
Drilling Fluid Performance Changes
The core objective of the solids control system is to maintain stable drilling fluid performance. Therefore, changes in drilling fluid parameters are important indicators of system operating status:
Density and Viscosity: If the drilling fluid density continues to rise, it may be due to insufficient separation efficiency of the solids control system, leading to excessive solids content. Abnormal viscosity fluctuations may reflect incomplete removal of fine particles or failure of chemical treatment agents.
Sand Content: Regularly sample and test the sand content of the drilling fluid. If the sand content exceeds 0.5%, it may be due to improper selection of the vibrating screen mesh size or insufficient centrifuge processing capacity.
Solid particle size distribution: The solid particle size distribution in the drilling fluid is detected using a particle size analyzer. An abnormally high content of fine particles (<20μm) may indicate a decrease in the separation efficiency of the desilter or centrifuge.
For example, a drilling team discovered a continuous increase in drilling fluid viscosity. Testing revealed excessive sand content, and further inspection revealed a damaged vibrating screen. Replacing the screen restored the drilling fluid performance to normal.
Rapidly assessing the operating status of the solids control system requires a comprehensive approach, utilizing parameter monitoring, on-site observation, sound and vibration analysis, and drilling fluid performance testing to form a closed-loop thinking process of ‘data-phenomenon-cause-measure.’ On-site technicians should establish a database of equipment operating benchmark values, conduct regular comparative analysis, and cultivate sensitivity to abnormal signals. Simultaneously, emergency plans must be developed. In the event of a serious anomaly (such as severe equipment vibration or a rapid deterioration in drilling fluid performance), the system should be immediately shut down for inspection to prevent minor malfunctions from escalating into major accidents.
