The solid control system and mud circulation system are two closely related but functionally positioned core systems in petroleum drilling engineering, and their differences are mainly reflected in the following five dimensions:

• 1. Differences in core functions
  • Solid Control System: Focused on the classification and treatment of solid particles in drilling fluids, it uses physical separation techniques (screening, swirling, centrifugation) to remove harmful solid phases such as rock cuttings and drill cuttings, maintaining stable drilling fluid performance. The particle size range of the treated objects covers 1μ m to several millimeters.
  • Mud circulation system: It constructs a complete circulation channel for drilling fluid from the bottom of the well to the surface, and provides power through a mud pump to achieve the basic functions of carrying rock debris, cooling the drill bit, and balancing formation pressure. It belongs to the carrier system of drilling fluid flow.
• 2. Comparison of Equipment Composition

  System Category	Core equipment	Technical Features
  Solid control system	Vibration screen, sand remover, mud remover, centrifuge, drying screen (Solid phase separation equipment accounts for over 60%)	-Mesh size: 40-325 mesh - Separation particle size: 1μ m-10mm - Processing accuracy: up to micrometer level
  Mud circulation system	Mud pump, high-pressure pipeline, mixer, mud tank, flow meter (power transmission equipment accounts for over 50%)	-Pump pressure range: 10-50MPa - Flow rate: 500-3000L/min - Cycle efficiency: 98%

• 3. Performance evaluation indicators
  • Solid control system:
    • Solid phase removal rate (usually 85%)
    • Drilling fluid recovery rate (80%)
    • Equipment processing capacity (m³/h)
  • Mud circulation system:
    • Cycle pressure stability (0.5MPa)
    • Pump efficiency (85%)
    • System sealing (leakage rate≤ 0.1%)
• 4. Typical Failure Modes
  • Solid control system:
    • Screen blockage (common in high viscosity drilling fluids)
    • Cyclone bottom flow fine (separation particle size deviation>10%)
    • Centrifugal vibration exceeds the standard (>5mm/s)
  • Mud circulation system:
    • Pump valve leakage (causing pressure fluctuation>10%)
    • Pipeline erosion (wall thickness reduction>20%)
    • Mixer shutdown (causing drilling fluid precipitation)
• 5. Collaborative Work Mechanism
  • Data flow interaction: The flow/pressure parameters of the mud circulation system provide processing load basis for the solid control system, and the solid content data feedback of the solid control system guides the adjustment of the circulation system displacement..
  • Energy coupling: The power of the mud pump (usually 300-1500kW) needs to be matched with the energy consumption of the solid control equipment (accounting for 15% -25% of the total energy consumption) to avoid system overload.
  • Emergency linkage: When the solid control system detects harmful solid phase exceeding the standard (such as barite content>5%), the circulation system can automatically initiate a bypass process to introduce contaminated drilling fluid into the emergency tank..

In typical application scenarios, solid control systems are like drilling fluids; Purification Workshop; And the mud circulation system is; Logistics artery;. For example, in the construction of shale gas horizontal wells, the solid control system needs to handle up to 30% of the rock cuttings return volume. At this time, the mud circulation system needs to maintain a flow rate of over 2000L/min to ensure the carrying of rock cuttings. The two are achieved through an intelligent control system: when the processing capacity of the vibrating screen decreases by 10%, the circulation system automatically reduces the flow rate by 5% to maintain solid-liquid ratio balance. This collaborative mechanism can improve drilling efficiency by 15% -20%.