@granite
A simple explanation using the Shale Permian basin as an example
Canada has two Large deposits untouched in Alberta and Saskatchewan
The Permian Basin, stretching across West Texas and southeastern New Mexico, stands as the most productive petroleum region in the United States, a sprawling, layered archive of ancient seas that now yields staggering volumes of energy. With nearly 29 billion barrels of oil and 75 trillion cubic feet of natural gas produced over its lifetime, the basin is not just an oil field; it is a complex industrial ecosystem where geology, chemistry, and economics constantly negotiate with one another.
At first glance, the goal in the Permian seems straightforward: drill for oil. But the subsurface rarely offers anything in isolation. Locked within the same porous rock formations as crude oil is natural gas, what the industry calls “associated gas.” It arrives uninvited yet unavoidable, a kind of energetic stowaway. For operators, this gas is both a burden and a bonus, a “frenemy” that complicates logistics even as it expands revenue potential.
When hydrocarbons reach the surface, the first task is separation. At the wellsite, large horizontal separators, industrial workhorses capable of handling thousands of barrels per day, divide the initial stream into crude oil, water, and raw gas. This gas is far from pure. Known as “wet gas,” it carries a mixture of methane along with heavier hydrocarbons like propane and butane, plus impurities such as water vapor and carbon dioxide. Left untreated, these components can corrode pipelines or disrupt downstream systems.
So the gas begins its own journey. It moves from the wellsite to processing plants, where it is dehydrated, purified, and fractionated. Water is stripped out to protect infrastructure. Carbon dioxide is removed to meet quality standards. Then the valuable components are separated: methane becomes pipeline-quality natural gas, while natural gas liquids (NGLs) are captured and sold into markets that feed everything from home heating to plastics manufacturing. What began as a byproduct quietly transforms into a critical feedstock for the petrochemical industry.
Yet the system is not always balanced. In recent years, the Permian has produced over 16 billion cubic feet of natural gas per day, an immense volume that sometimes exceeds the capacity of pipelines designed to carry it away. When infrastructure lags behind production, operators face difficult choices. Gas prices can collapse under oversupply, and in more constrained situations, companies may resort to flaring,burning excess gas, or venting it directly into the atmosphere. Both practices draw scrutiny, particularly because methane is a potent greenhouse gas. Even so, expanding pipeline networks and stricter regulations are gradually reducing these inefficiencies.
Meanwhile, the oil itself follows a different path. After leaving the wellsite, crude oil is transported to refineries, where its transformation is both methodical and almost elegant. Heated in furnaces and fed into distillation towers, the crude separates according to boiling points. Lighter fractions rise and condense into products like gasoline, while heavier components settle lower in the column. Through processes such as catalytic cracking, large, unwieldy hydrocarbon molecules are broken into smaller, more useful ones, turning dense residues into fuels that power engines and industries.
From a standard 42-gallon barrel of crude oil, the output is surprisingly expansive. Roughly 19 to 20 gallons become gasoline, accounting for about 44 percent of the barrel. Another 11 to 13 gallons emerge as diesel and heating oil, alongside smaller but vital quantities of jet fuel, lubricants, waxes, asphalt, and petrochemical feedstocks. In fact, due to processing gains, the total volume of refined products can exceed the original barrel, reaching about 45 gallons. What starts as a dense, opaque liquid becomes a spectrum of materials embedded in daily life, from the fuel in a car to the plastic in a smartphone.
In this way, the Permian Basin is more than a source of oil. It is a place where nothing comes up alone and nothing goes to waste without consequence. Oil drives the operation, but gas reshapes its economics. Infrastructure dictates feasibility. Chemistry unlocks value. And hovering over it all is a growing awareness that efficiency is no longer just about profit, it is also about responsibility.
Some calculation excerpts from:
Régie de l'énergie du Canada