HPGL is a form of gas lift that combines the advantages of conventional gas lift and the lift capacity of ESPs. Conventional gas lift is very robust in the handling of gas and hi-solids fluids. However, it is unable to produce fluids at the higher rates when compared with ESPs.
While ESPs offer very high flow rates, they are comparatively expensive to install and maintain. They are prone to failure when sand and gas are present – as is the case in most unconventional wells. When these elements enter the production stream, they reduce the life of the ESP. Operator cost then goes up as ESPs are often expensive to repair and production is also lost when wells are shut-in for a workover.
Alternatively, HPGL offers the same or better rates of ESP fluid production without the up-front expense of repairs, costly workovers, and lost production.
How does HPGL work?
HPGL is a surprisingly simple process, and an impression may be, it’s too good to be true.
The system works by injecting compressed, natural gas down the full length of the production string, where it exits the open-ended tubing at Total Depth. At that point, it combines with the mixture of oil, water, and formation gas, reducing fluid column density and bottom hole pressure. The well fluids are then lifted to the surface through the now much larger flow area of the annulus. High production rates are possible - with no downhole components, no downhole moving parts.
If HPGL is such a simple, yet major improvement to an artificial lift system –while also saving money and maintaining production at high rates--why don’t more Operators make the switch?
First, the simplicity of the design may present a challenge to accepting this “too good to be true” artificial lift option. Previously unavailable compression technology now provides the capability to inject higher volumes of high-pressure gas through a deeper, single exit point. This means operators can potentially save hundreds of thousands of dollars annually per well with zero downhole-based NPT for gas lift components.
Second, due to the high-pressure nature of this method, Operators may be concerned that HPGL operations can be volatile and dangerous.
Estis compressors are designed and fabricated according to stringent industry codes and standards. These codes and standards include margins of safety and require rigorous design efforts to ensure reliable engineering. In accordance with industry codes and standards, fabricated components undergo Non-Destructive Examinations (NDE) to validate that the actual product conforms to the design specification.
All process pipe and pressure vessels are then hydrotested per industry standards such as applicable ASME Code B31.3 requirements. Or as an example, 1.3 x Maximum Allowable Pressure or MAWP).
Finally, the Estis Compression HPGL system comes with complementary classroom and hands-on safety training for the production operations crew, which further supports a historical incident free safety record.