The oil industry keeps finding new ways to maximize production from existing assets.
One operator has identified best practices for resurrecting production at dead gas condensate wells, while another has used machine learning (ML) to locate new reserves in a giant brownfield. Both highlighted their work during the International Petroleum Technical Conference (IPTC) in Kuala Lumpur in February.
After liquid loading halted gas production from some of Saudi Aramco’s wells, the operator identified two best practices for reviving production.
The resulting effort realized “significant gas gain” from previously dead wells and made it possible to prolong the productive life of those fields, Qassim Alhashim, a gas production engineer for Saudi Aramco, and coauthors wrote in IPTC 25106, which he presented during the conference.
Liquid loading occurs in a gas condensate reservoir when the reservoir pressure drops below the bubblepoint and liquid starts to drop out of the gas phase. This isn’t problematic if there is enough energy provided by the pressure difference between the reservoir and wellbore to bring the liquid to the surface. But if the hydrostatic pressure exceeds the reservoir pressure, production will cease, Hashim said.
“Liquid loading is a common challenge in gas condensate producers, where liquid accumulation can hinder the flow of gas, reducing the well productivity, or in some cases, stop it altogether,” he said. “Understanding the common challenges of liquid loading is crucial for effective management and mitigation.”
One of the most effective and economic ways to detect liquid loading in a wellbore is through a static bottomhole pressure (SBHP) survey, typically conducted using pressure gauges conveyed on slickline. The survey estimates reservoir pressure and detects changes in fluid gradient, with steeper fluid gradients typically indicating liquid loading, the paper noted.
It’s also possible to diagnose liquid loading by performing multirate tests through a three-phase separator where the wellstream flow rates are accurately measured, the authors wrote; an elevated rate of liquid production also indicates the tendency toward liquid load.
Liquid loading causes operational challenges like reduced gas rate, accelerated corrosion and scaling, and slug flow conditions, Hashim said. It also presents challenges to the business, such as reduced revenue due to lower production, higher operational costs from the need for workovers and cleanout operations to remove scale buildup, and more complex surface designs due to accommodate electrical submersible pumps or gas lift, he said.
