When producing gas from a gas field or oil from an oil field, water is a common by-product. Also, the oil emulsion consists of a combination of gas, oil, water and, traces of solids. Let us look at the process of treating wastewater, typically using produced water pumps or produced water disposal pumps.
What is Produced Water?
Produced water refers to the water produced as a by-product when extracting natural gas and oil. Gas and oil reservoirs often contain water. Produced water that has a high quantity of minerals or salt content is known as brine. It may also contain other contaminants such as the following:
- Total dissolved solids (TDS)
- Grease and oil
- Dispersed oil
- Suspended solids
- Heavy metals
- Dissolved and volatile organic compounds
- Dissolved gases and bacteria
- Chemicals or additives used in products such as scale and corrosion inhibitors, biocides, and emulsion and reverse-emulsion breakers
In addition to this, produced water may also carry toxic substances such as hydrogen sulphide (H2S). H2S is a colourless, flammable, poisonous and corrosive gas that is soluble in water. You can notice it by its rotten egg smell, at very low concentrations. It can prove to be fatal when present in a higher concentration. It is imperative to have safety precautions in place when H2S is present in excess quantity in the water or fluid streams.
How to Manage Produced Water?
The most common method of dealing with produced water is deposing of it using a piece of equipment such as water pump skids or produced water disposal pumps. Water disposal refers to pumping the water back into a formation that no longer produces oil or gas economically. This is also called water injection and requires positive displacement pumps to push the water back into the reservoir at high pressures through an injection well.
Wastewater Disposal Facilities
Oil batteries and gas plants typically use an inlet separator, free water knock-out drum, or treater to separate the water from oil or gas. The water is then sent to a wastewater facility for further processing. This facility is either located at the same site or at a different location.
The purpose of the wastewater disposal facility is to remove any hydrocarbons or solids so not to damage the formation. A typical process is as follows:
- The produced water enters a produced water storage tank.
- The tank acts as a separator, allowing the solids to settle at the bottom and the oil to float to the top.
- A booster pump helps to draw the water off the side of the tank.
- Filters are placed between the tank and the booster pump to remove any contaminants from the wastewater stream.
- Water is then sent from the booster pump to the injection pump.
- The water injection pump then pushes the water over to the injection well at high pressures and disposes of the water into the formation.
Reciprocating Plunger Pumps
Reciprocating plunger pumps are also known as duplex or triplex pumps because of the number of plungers. A duplex indicates two plungers and triplex means it has three plungers. The higher the volume and pressure, the more plungers are required to pump the fluids.
Triplex plunger pumps are known for having a consistent output of 0.25 to 240 gallons per minute at pressures varying from 100-5,000 pounds per square inch. They are low-maintenance solutions for high-pressure applications and are energy-efficient per volume of fluid pumped.
Let Us Build a Water Pump Skid that Meets Your Needs
At Aspire Energy Resources Inc., we can help you build a skid that houses the filters, booster pump, injection pump, and interconnecting piping as per your specifications. Water disposal injection skids are an economical alternative to installing each piece of equipment, separately at the site. We can help you combine this with refurbished injection pumps to reduce the overall cost.