A decade has passed since the US shale sector became excited about the idea that enhanced oil recovery (EOR) could be applied in tight rock formations. Intrigue boomed in 2016 when EOG Resources reported that its huff-and-puff gas injections were delivering double-digit production gains in wells in the Eagle Ford Shale of south Texas. The early enthusiasm, however, soon clashed with the harsh realities of geology and business. The surface compression equipment required for cyclic gas injection was costly and involved long lead times. Not everyone had a high-volume supply of gas. Then, within 2 years of EOG’s announcement, a downturn in oil prices forced many operators to curtail pilot programs or kill larger-scale efforts. At the same time, tight-oil and -gas producers were refining their understanding of shale reservoir behavior. Fracture networks were shown in many cases to be more extensive and better connected than first assumed. This often made it difficult to establish the pressure containment and contact efficiency needed for effective gas injection. EOG itself gradually stepped back from public discussion of its shale EOR operations. But industry efforts to test shale EOR never really ended, and the topic is now gaining renewed momentum. Why? It may simply be a matter of time. “Shale-production growth across the US is starting to slow down,” said Vishal Gupta, general manager for Occidental Petroleum’s EOR ventures unit. “We anticipate that within the next 5 to 8 years or so, shale production will peak and then be on a fairly steep decline thereafter—and EOR is a very meaningful way to be able to offset that decline.” Gupta spoke at the recent SPE Improved Oil Recovery Conference in Tulsa, Oklahoma, where operators and technology developers presented new papers and perspectives on shale recovery. He noted that Occidental recently formed its EOR ventures unit to accelerate the development and deployment of shale-focused EOR technologies, reflecting the company’s view “that EOR is the future of the shale industry.” Occidental has evaluated shale EOR for the past 10 years, focusing primarily on CO2 injection with a lesser emphasis on using other miscible gases. Though its most recent CO2 pilots, Gupta said, have been “very encouraging,” with reported production uplift in the range of 40 to 50%. The company is now advancing commercial-scale CO2 projects in the Permian Basin, including two in Texas and one in New Mexico, and has several more planned. Gupta said Occidental defines EOR commercialization as being “a standalone economic business that’s delivering free cash flow.” Chevron has emerged as the other large shale producer in the Permian to talk openly about its improved recovery work. Although, the supermajor is much more focused on injecting surfactants as part of the initial hydraulic-fracturing treatment. Birlie Bourgeois, general manager of applied technology solutions for Chevron, said the company is “100%” leaned into the approach it first outlined in technical papers published in 2023 and covered by JPT here. “We think there is a benefit to pumping a chemical that both can liberate oil and mitigate formation damage,” he said, adding that the company is evaluating a variety of chemicals to help on this front.
Trent Jacobs (Mon,) studied this question.