How do shale shakers and mud tanks work together?

In drilling solids control systems, shale shakers are responsible for the primary purification of drilling fluid, while mud tanks serve as the carriers for drilling fluid storage, circulation, and secondary treatment. Through a closed-loop synergy of "separation-receiving-storage-circulation," the two work together to ensure stable drilling fluid performance, reduce solid waste emissions, and improve drilling efficiency. The following will provide a more detailed explanation using application cases from TR Solids Control.

I. The Logic of Collaborative Operation between shale shaker and Mud Tank

The synergy between the shale shaker and the mud tank is essentially a closed-loop process of "graded purification - circulating storage - precise control". The two form a functional chain around the "purification - recovery - reuse" of drilling fluid.

II. Collaborative Work Process

1. Return slurry introduction: directional conveying, precise receiving

   During drilling operations, drilling fluid carrying drill cuttings (return slurry) is directly introduced into the feed box of the shale shaker through the drilling fluid return pipe. TR Solids Control's shale shaker adopts a "wide feed inlet + anti-splash guide plate" design to ensure that the return slurry is evenly distributed on the screen surface; at the same time, the discharge port of the shale shaker is precisely connected to the primary feed chamber (transition chamber) of the mud tank, and the sealed guide chute avoids drilling fluid leakage and dust, achieving "seamless connection".

2. Solid-phase separation: high-efficiency purification, directional slag removal

   After the shale shaker is started, the drilling fluid on the screen surface forms a thin layer flow through the high-frequency linear/elliptical shale shaker. Solid particles such as drill cuttings and rock powder are intercepted by the screen and discharged in a directional manner along the inclined direction of the screen surface to the drill cuttings collection device (such as a slag discharge trough or screw conveyor), avoiding the solid particles from flowing back to the mud tank; while the primary purified drilling fluid flows directly into the mud tank transition chamber through the gaps in the screen.

3. In-tank grading: storage + pretreatment, stabilizing mud properties

   The mud tank adopts a modular compartment design (TR Solids Control can customize 3-5 compartment structures), which is separated from the shale shaker to form a stepped matching:

   First chamber (transition chamber): Receives the purified liquid conveyed by the shale shaker. The impact of the liquid flow is reduced by the buffer inclined plate inside the tank, allowing the fine solid particles that are not completely separated to settle naturally.

   Second compartment (purified fluid compartment): Receives the upper layer of clear fluid from the transition compartment through the overflow port of the partition. The tank is equipped with an explosion-proof agitator (to prevent drilling fluid sedimentation and stratification) and a liquid level sensor (to monitor the liquid volume in real time). It can also be linked with secondary solids control equipment such as degassers and desanders to further purify the drilling fluid.

   The third compartment (supply compartment): stores qualified drilling fluid, which is pressurized and delivered to the drilling pump through a centrifugal slurry pump and then reinjected into the wellbore for recycling;

   Special compartment (waste liquid compartment): collects excessive drill cuttings flushing fluid or drilling fluid that has failed to meet performance standards separated by shale shaker, and then discharges it in compliance with environmental protection treatment equipment.

4. Dynamic linkage adjustment: Adapts to changes in operating conditions and ensures continuous operation.

   Liquid level linkage: The mud tank liquid level sensor provides real-time feedback on the liquid volume. When the liquid level is too high, the shale shaker feed valve is automatically adjusted to reduce the processing capacity, or the standby shale shaker is activated to divert the flow. When the liquid level is too low, the drilling pump is linked to reduce the discharge rate to avoid running the pump dry.

   Performance linkage: If the shale shaker becomes clogged (due to drill cuttings accumulation), it will cause backflow and overflow. At this time, the overflow alarm device of the mud tank will be triggered to remind the operator to clean or replace the screen in time (TR Solid Control shale shaker adopts quick-release screen, which improves replacement efficiency by 50%).

   Environmental protection linkage: The drill cuttings separated by the shale shaker are discharged through a sealed slag discharge system, and the top of the mud tank is equipped with an anti-volatile cover and a waste gas recovery interface. The two work together to avoid environmental pollution caused by drilling fluid volatilization and leakage, which meets the environmental protection standards of the oilfield.

III. Advantages of Collaborative Work

1. Solids control efficiency improved by 30%: The shale shaker adopts high-frequency vibration and multi-layer screen design, which works in conjunction with the sedimentation of the mud tank compartment, achieving a solids removal rate of over 95%, reducing the load on subsequent solids control equipment;

2. Drilling fluid loss reduced by 20%-40%: Closed-loop synergy avoids drilling fluid leakage and contamination, increasing the drilling fluid recycling rate to over 90%, and significantly saving on the cost of new slurry preparation;

3. Operational continuity is ensured: the modular mud tank can be quickly expanded, and the shale shaker supports multiple units in parallel (TR Solids Control can customize a linkage scheme of 2-4 units), adapting to the changes in return mud volume at different drilling depths (vertical wells / horizontal wells / shale gas wells);

4. Environmental compliance: The shale shaker features a sealed slag discharge system, and the mud tank is designed to prevent overflow and volatilization, thus eliminating drill cuttings scattering and mud leakage, meeting the national requirement for zero emissions of drilling waste.

IV. TR Solid State Control Collaborative Practice Case

The "shale shaker-mud tank collaborative system" designed by TR Solids Control in a shale gas drilling project in Xinjiang Oilfield fully demonstrates the high-efficiency linkage value of the two and solves the pain points of "incomplete purification and low circulation efficiency" in traditional systems.

The project involved drilling to a depth of 5,000 meters. The drilling fluid had a high sand content and the shale cuttings had uneven particle size. Traditional systems had the following problems: poor connection between the shale shaker and the mud tank caused drilling fluid to overflow; the drilling fluid after screening still contained a large amount of fine rock cuttings, the mud tank had an excessive sedimentation load, and the drilling fluid needed to be treated before reuse, which was time-consuming and labor-intensive.

TR Solid Control has built a collaborative system of "three-level flow guidance + intelligent linkage" tailored to the characteristics of the project.

1. Vibration screening type and optimization: The TRZS series high-frequency linear shale shaker is adopted, equipped with a 200-mesh wedge screen, the vibration frequency is adjustable from 30-50Hz, and the processing capacity is up to 120m³/h; the feed box of the screen body is equipped with a "buffer diversion plate" to evenly distribute the drilling fluid to the full width of the screen and avoid local overload.

2. Modular design of mud tanks: The modular mud tanks are connected in series with 4 tanks to realize the functions of "buffering and diversion - coarse sedimentation - reagent regulation - circulation and storage" respectively: Tank No. 1 (buffer tank) is connected to the shale shaker outlet by a 15° inclined diversion pipe and has a built-in liquid level sensor and automatic overflow valve; Tank No. 2 (sedimentation tank) is equipped with a honeycomb inclined tube sedimentation device to enhance the settling of fine rock cuttings; Tanks No. 3 and No. 4 are equipped with variable frequency agitators and online densitometers and viscometers to monitor drilling fluid performance in real time.

3. Intelligent linkage control system: Through the TR-Control system independently developed by TR, the parameters of the shale shaker and the mud tank are linked. When the liquid level of the No. 2 tank exceeds 80%, the system automatically increases the frequency of the shale shaker by 5Hz. When the drilling fluid density of the No. 3 tank is higher than 1.2g/cm³, the feed valve of the shale shaker automatically reduces the opening and triggers the drain valve of the No. 2 tank to open and discharge the precipitated rock cuttings.

After being implemented in the project, this collaborative system improved purification efficiency, enhanced circulation stability, and reduced costs. It is suitable for scenarios such as oil and gas drilling, shale gas development, coalbed methane drilling, and geothermal drilling.

The coordinated operation of shale shakers and mud tanks is crucial for the efficient operation of drilling solids control systems. Through a closed-loop process of "precise front-end purification - efficient mid-end storage - intelligent back-end control," drilling fluid can be efficiently recovered and reused. TR Solids Control makes the coordination between shale shakers and mud tanks more precise, durable, and environmentally friendly, providing oilfield customers with a complete solids control solution from equipment to system.