Acid Kill Pump Trucks: How They Work
Acid kill pump trucks — also called acidizing trucks or acid pump trucks — are specialized oilfield service vehicles designed to pump acid down the well. Acidizing is a well stimulation technique where you pump acid into the reservoir to dissolve rocks and open up the flow channels. It's used to increase production from oil and gas wells. Acid kill pump trucks are the equipment that makes acidizing possible.
How Acid Kill Pump Trucks Are Built
An acid kill pump truck looks similar to a cementing truck or a frac pump truck, but it's built with special materials to handle corrosive acid:
The Pumping Skid. This is where the acid pumps are. Unlike regular pumps that handle water or cement, acid pumps are made with corrosion-resistant materials — stainless steel, Hastelloy, or special coatings. Acid is very corrosive, and it will eat through regular steel pumps in no time. The pump plungers, valves, and fluid ends are all made with acid-resistant materials.
The Acid Tanks. The truck carries the acid in special tanks. These tanks are also made with corrosion-resistant materials, and they have special coatings on the inside to protect the steel from the acid. The tanks are usually divided into compartments, so you can carry different types of acid and chemicals on the same truck.
The Mixing System. Acidizing jobs often require mixing acid with water, additives, and inhibitors. The truck has a mixing system to blend the acid to the right concentration, and to add the right chemicals. The mixing system is also built with acid-resistant materials.
The Control Cabin. The operator sits in a control cabin, with all the gauges and controls. Because acid is dangerous, the control cabin is usually sealed and pressurized, so the operator doesn't breathe acid fumes. The cabin also has safety features, like emergency shutoff buttons and eyewash stations.
The Manifold and Piping. All the piping and valves that carry the acid are made with acid-resistant materials. They're also designed to be easily flushed and cleaned after the job. Acid is dangerous, and you can't let it sit in the piping — it will eat through the metal.
What Kinds of Acid Are Used?
Acidizing uses different types of acid, depending on the rock formation:
- Hydrochloric acid (HCl): This is the most common acidizing acid. It's used for carbonate formations — limestone and dolomite. It dissolves the carbonate rock, opening up flow channels.
- Hydrofluoric acid (HF): This is used for sandstone formations. It dissolves the silica in the sandstone, opening up the pore throats. HF is very dangerous — it's one of the most corrosive acids there is.
- Acid blends: Sometimes you use a blend of HCl and HF, for formations that have both carbonate and sandstone. You can also add additives — corrosion inhibitors, friction reducers, iron control agents, and others.
FAQ
Q: Is acidizing dangerous?
A: Yes, acidizing is dangerous. Acid is corrosive, and acid fumes are toxic. That's why acid kill pump trucks are built with special safety features, and why acidizing crews are specially trained. But when it's done properly, acidizing is a safe and effective well stimulation technique.