PECL™ Makes the Most of Neglected Wells

It’s the law of the jungle when it comes to oil-and-gas exploration: after a time prolific, long-life pools tend to be neglected because while year after year after year they produce, they eventually are taken for granted and don’t get the attention they should later in their life, meaning they are essentially forgotten even though they still may have much more to offer.

That was the case with a series of wells owned by a leading exploration company that are located in the Eckville field, just west of Red Deer, Alberta, midway between Calgary and Edmonton. First drilled in the 1960s, the Eckville field has produced more than 1 trillion cubic feet of natural gas in the ensuing years, making it one of the most bountiful gas fields in Alberta. But after producing as much as 1 million cubic feet per day for most of their life, the wells in question fell victim to declining bottom-hole pressures that saw them producing just a fraction of their typical output.

“This company is one of the top three producers in that area,” said Steve Cannon, the Canadian Supply Chain Manager of FB’s Red Deer office, “but with one particular well, they were ready to write off the books nearly 2 billion cubic feet—which they eventually didn’t—because they thought the well was dead and couldn’t be recovered.”

PECL™ is a process that can be used in a wide range of wells, from those with long, perforated interval reservoirs to those with low-pressure reservoirs. A special application for intermittent gas-lift is called Chamber Lift, in which gas is injected into the annulus, allowing it to move the fluid from the chamber into the production tubing. However, this process can result in a high level of gas slippage through the fluid slug, leading to liquid fallback that compromises gas recovery and wastes energy. To combat this condition, the PECL™ technique adds a plunger to the chamber-lift operation, thereby improving the efficiency of liquid removal and almost eliminating liquid fallback. This is possible because the introduction of the plunger creates a solid interface between the liquid slug above the plunger and the gas energy that is below the plunger, which effectively sweeps the tubing clear of liquid on its ascent.

PECL™ was installed on the first Eckville well in August 2004 and has since been added to nine other under-producing wells in the area, with spectacular results in all cases. All of the wells are producing at least 500,000 cubic feet of natural gas per day and will eventually produce as much as 20 billion cubic feet that the exploration company would have left behind without the use of PECL™.