Typically Large oilfield storage tanks are built up on aggregate bases and have loose unpacked gravel slopes to divert water flow. These slopes are typically unprotected or have a thin asphalt layer to prevent erosion. During rain fall, water collects at the top of these tanks and drains below onto the gravel slopes in collected areas.
When the rain fall hits the unprotected aggregate typically it starts to create erosion channels and washes away the gravel. Should this situation not be addressed the soil erosion becomes increasingly deeper and deeper therefore starting to affect the structural stability of the tank pads. If the erosion grows severe enough this could cause the tank to sink and/or to shift on the pad above which creates a costly project to fix.
If the tank slopes are coated with the typical asphalt or SS1 coating, although this provides protection, it is not a perfect solution. Asphalt and SS1 are porous and soak up moisture, this moisture freezes in the winter and causes cracks and fractures to develop throughout the surface. Given enough time these cracks start to allow more and more water into the gravel tank bases. This water then flows down to low points under the tanks and pools, and has the potential to corrode the bottoms of the tanks. This causes a variety of issues with the integrity of the tank shells, all which lead to costly repairs.
The Storage Tank Solution:
Halo has developed a new form of Oilfield Tank Skirting that consists of pre-sprayed panels of Polyurethane plastic that are physically bonded to the bottom of the tanks either via the annular ring or tank base plate. From there the polyurethane tank liner is extended out and over the gravel swales and seamed together to create a monolithic liner that repels moisture. Therefore in the event of a rain storm the collecting water falls from the top of the tank, hits the new oilfield tank apron and is diverted into the drainage pond without any contact with the soil; thus eliminates the erosion from occurring. The Polyurethane oilfield tank apron also does not allow moisture to penetrate through it or soak into it, consequently eliminating the destructive force of freeze/thaw cycles. It also prevents moisture from finding its way to low points under the tanks, collecting, and corroding the metal tank base.
This newly developed system will keep the tank base intact, the gravel pads stable, and divert the water flow as intended.