Drilling Fluid Tank Layout: The “Invisible backbone” Determining Drilling Efficiency and Safety.

On oil drilling sites, drilling fluid is metaphorically called the “blood of drilling”, and the layout of the tanks that carry this circulation system is the “invisible backbone” ensuring the pure flow of this blood. A scientific tank layout not only enables efficient connection of drilling fluid purification , storage and circulation processes but also directly impacts drilling efficiency, equipment lifespan, and operational safety.

Today, we will break down the core logic of this key link.

1. Core Principle of Layout: Safety, Efficiency and Compliance.

    Tank layout is not a simple stacking of equipment; it must follow three core principles.

     · Process Priority Principle: Strictly arrange according to the flow direction of "wellhead return → rough purification → fine purification → storage → recirculation" to ensure the natural flow of drilling fluid and reduce pipeline resistance and power loss.

     · Safety and Compliance Principle: the tank area must maintain a safety distance of 11-18 meters from the wellhead and at least 20 meters from hazardous areas( such as oil tank farms and power generation rooms). meanwhile, maintenance channels of no less than 1.5 meters and clear escape routes should be reserved.

     · Local Adaptation Principle: Adjust the layout based on well site terrain, rig type, and seasonal wind direction. For sour oil and gas wells, the tank area should be set downwind of the prevailing wind to avoid the accumulation of harmful gases.

2. Classic Layout Scheme: The Golden Process of Four-level Zoning.

    Mature drilling fluid tank system usually adopt a “series+ parallel” four-level zoning layout to achieve the full-process treatment of drilling fluid.

     ·Receiving and Pre-Purification Zone: Front Layout of the First Line of Defense: Adjacent to the wellhead mud return pipeline, the core equipment is shale shaker tanks(1-2 unit). Shale shaker and vacuum degassers are installed on the tank top to prioritize the removal of cutting larger than 74 microns and harmful gases. The degasser exhaust pipe must extend more than 15 meters beyond the tank area to avoid gas backflow and accumulation. This area is the “first checkpoint” for drilling fluid purification and must be located close to the wellhead to shorten the return path.

     ·Deep Purification Zone: Core Hub for Fine Treatment: Connected to the rear of the pre-purification zone, it consists of desander tanks, desilter tanks and centrifuge tanks forming a “three-level purification echelon.” Desander tanks are matched with desanders to treat 40-74 micron particles, desilter tanks are paired with desilter to separate 10-40 micron mud particles, centrifuge tanks capture colloidal particle smaller than 10 microns though centrifuges. Special agitators are equipped in each tank to avoid solid phase settlement forming “dead zone” and ensure thorough purification.  

     ·Storage and Preparation Zone: Guarantee base for Stable Performance: It include 2-4 storage tank and a standby tank for storing qualified drilling fluid after purification. Some tanks integrate agitators and chemical dosing devices, which can adjust performance indicators such as drilling fluid density and viscosity in a real-time. The tank bottom is designed with a 1%-2% slope and a sand settling hopper to facilitate regular sewage discharge and cleaning. Meanwhile, precise liquid level control is achieved through liquid level gauges and overflow pipes. As the reservoir of the drilling fluid, this area must ensure sufficient capacity, usually 1.5-2 times the circulation volume.

     ·Circulation Power Zone: Power Core for Continuous Circulation: Composed of 1-2 circulating pump tanks, close to the storage area and the wellhead direction, with the drilling pump installed next to the tank. The suction pipe in the tank must be precisely designed to avoid cavitation and ensure the stable delivery of qualified drilling fluid back to the wellhead, completing the entire circulation process. This area is the heart of circulation system, and the pipeline layout should be minimized to reduce power loss.

3. Core Value of Layout：Dual Improvement of Efficiency and Cost.

    A scientific tank layout can bring significant operational value: it can not only increase drilling fluid purification efficiency by more than 30% and extend the lifespan of equipment such as drill bits and drill pipes by 20%, but also reduce drilling fluid loss and waste discharge, lower environmental compliance costs. In complex working condition such as horizontal wells and high -sulfur wells, a reasonable layout is even a key guarantee to avoid accidental such as well collapse and equipment sticking.

    Drilling tank layout seems to be the spatial arrangement of equipment, but in fact, it is a comprehensive embodiment of drilling technology, safety specifications, and engineering experience. Only by choosing the right layout scheme can the drilling fluid circulation system truly become the “power engine” for efficient drilling.