Being in the oil & gas industry, I have learned that there are so many nooks and crannies within the industries. More often than not, I am learning something new whether it is a term, process, or division of the industry I didn’t know existed. One term that I have often heard is the term “gas lift.” Sometimes more than others depending on what niche of the industry you are most familiar with. So what does it mean and what is it good for?
What is a Gas lift?
Gas lifts use the artificial lift method by injecting gas into the production tubing to raise water or oil. The gas injected is high-pressure gas by adding bubbles of compressed air and vapor. This acts to lower the hydrostatic pressure at the bottom of the tubing, reducing its density. The injected gas is normally injected down the tubing annulus and enters the production tube through multiple gas lift valves. The fluid is then forced up and out of the wellbore. This process allows the fluids to begin flowing when they can no longer flow on their own.
The video below is a great visual for understanding the method a gas lift uses. It shows the gas being injected, entering the gas lift valves, and allowing fluids to begin flowing again.
Injecting the Gas
When injecting the gas downhole, it could be injected continuously or intermittently. This depends on the way the gas lift equipment is arranged and producing characteristics. Deciding just how much gas needs to be injected depends on the well conditions and geometries. If too much gas is injected, the economics may not be sound but if too little, then production may not be maximized.
For the gas to be at the appropriate pressure to be re-injected, the process requires a compressor which will raise the pressure of the gas to the appropriate levels of re-injection.
History Lesson
This method of using a gas lift is not by any means new to the oil & gas industry. In fact, they were using this method in the mines to help lift water out of mine shafts back in 1797. For the oil & gas industry, the gas lift was used in Pennsylvania to help production in oil wells in 1864. The compressed air being used was an air pipe that brought the air to the bottom of the well. Since then, we have adapted and perfected this method into the method we use today.
Fun Fact: This method of using compressed air to lift fluids is used in other applications such as dredging, underwater archaeology, and used to in aquariums to help keep the water circulating. Interesting what you can learn from other applications and how you can apply it to the task at hand!
So why does CROFT like gas lifts? Well like we’ve learned, gas lifts result in having high-pressure fluids such as oil and gas. The majority of CROFT’s units are rated for higher pressure. Higher pressure allows them to work more efficiently, which ultimately could save money. Check out the gas processing equipment that we offer.
http://www.glossary.oilfield.slb.com/en/Terms/g/gas_lift.aspx
