Natural Gas

The fourth-largest listed producer of natural gas, we have proved our ability to discover and produce gas fields time and again since the 1950s. Not surprisingly, we have a number of world-first technology breakthroughs to our credit, as well as a highly diversified gas portfolio.

Highly diversified sources of gas

Like oil, natural gas arises from the decomposition of organic matter, such as microorganisms and plants, trapped in sedimentary rock millions of years ago. This long, often turbulent, transformation process created either gas or oil, depending on pressure and temperature conditions, and most often a mix of the two in the same deposit. For that reason, oil production is usually accompanied by the production of what is known as associated gas. On the other hand, many reservoirs contain gas only, sometimes coupled with condensate, which is a gaseous hydrocarbon that condenses and becomes liquid when it leaves the production well. Composed primarily of methane, natural gas can also be mixed with so-called sour or acid gases, such as carbon dioxide (CO₂) and hydrogen sulfide (H₂S). Although the former is a leading culprit in global warming, the second, lethal in very low doses, can be used to produce sulfur.

Gas exploration and production

Gas and oil share the same exploration and production technologies. Finding fields draws on a combination of geological and geophysical expertise. Gas, however, can be easier to produce than oil, because it moves around more freely in reservoirs than its stickier cousin. As a result, bringing gas to the surface rarely requires special production techniques such as injecting water into reservoirs, a common practice to give oil a “boost.” On the other hand, once out of the well, natural gas requires specific types of treatment, in line with its composition, to make it commercial grade.

Responsible management of associated gas

For a long time, the lack of commercial markets close to production sites meant that the only possible solution for dealing with associated gas was flaring. Our commitment to limiting our greenhouse gas emissions has radically changed the equation. E&P has applied a strategy for commoditizing associated gas for several years now, in which flaring is banned in all new developments under normal production conditions. Geology permitting, the gas is reinjected under pressure into the reservoir, where it pushes the oil up to production wells like a piston. In addition, our very strong involvement in the liquefied natural gas (LNG) sector also offers E&P a major outlet for monetizing associated gas, which is used to supply a number of liquefaction plants worldwide.

Managing unconventional gas

Like oil fields, the first gas reservoirs developed were the easiest to produce, that is, the richest in methane and the most likely to allow the gas to escape from the rock matrix. With one huge exception, however, for which Total E&P can take credit. We were the first in the world to meet the challenge of producing a sour gas field, Lacq in southwestern France, which came on stream in the 1950s. A historic leader in this specialized niche, Total is currently one of the very few operators to possess the technologies needed to develop and treat very sour or acid gas, which until just recently was out of reach for both financial and environmental reasons.

Tight gas reservoirs also rank high as a development priority to keep pace with the forecast steady growth of gas markets. These rock formations, which are too impermeable for the gas to flow freely, require expertise and cutting-edge technologies to coax out their valuable resource.

Lastly, gas in deeply-buried reservoirs, defined as more than 4,000 meters underground, falls into the realm of frontier production. Here too, it will take high-level capabilities coupled with innovative technologies to meet the challenges created by the high temperatures and high pressures deep in the Earth’s core.