Abstract
Liquid loading is a common problem in many gas wells in the Gulf of Thailand. At the late stage of well life, reservoir pressure declines, gas production rates decrease, and liquid begins collecting on the wall of the tubing and accumulates at the bottom of the well, eventually killing the well. This paper presents promising results from foam-assisted lift (FAL) field trials to remove liquids, re-establish flow, and increase production in previously idle wells.
The injection of foaming agents can be used to remove liquids through artificial lift. High downhole temperatures in Gulf of Thailand wells requires special foaming agents that can operate at 450°F. Using high-temperature foaming agents in nearly dead wells can extend their life by reducing the production decline rate and preventing premature water loadup. Because foam density is significantly lower than liquid density, hydrostatic pressure is reduced, which assists the flow of fluids from the bottom hole to the surface, resulting in increased gas production rates and reserve recovery rates compared to natural flow.
An operator in the Gulf of Thailand experienced promising results from a field trial using high-temperature FAL with batch treatments in five high-temperature wells in the offshore field. Three wells that were previously not flowing were able to flow to the production system after treatment. One well was able to flow at even higher rates after the FAL treatment compared to prejob rates. Only one well did not respond to the treatment. Understanding the FAL procedure and addressing critical issues before implementing the technology can help enhance mature field production in otherwise idle wells.
Using FAL in mature wells with low or no production can help remove liquid accumulation at the bottom of the well, preventing premature water loadup and returning idle wells to production.
