These odd old oceans are the beginning of a large part of today’s energy policy. From the Gulf to the Arctic, it’s where the big money goes.
The inland sea accumulated a great thickness of marine sediments, largely sandstones, tongues of shale, and fine-grained limestone chalk made of microscopic shells.
Deposits also rained from lakes, swamps and floodplains, and yes, high-energy coastline.
The seas retreated toward the end of the Jurassic.
World-wide climates were warm during this time and most of North America was subtropical. Ferns and conifers were dominant along with more than seventy types of dinosaurs, swimming and flying reptiles, sharks, and small mammals.
And the mountains lifted
Sediments were shed from the rising mountains and spread as great fans of gravel, sand and silt covered the intense growth until we arrived walking on the Great Plains east of the Rocky Mountains.
Decomposition in many areas were compressed to coal. Other areas fractured and settled to trap modern crude oil and natural gas.
The USA was the world’s number one oil and gas producer until offshore imports became less costly than domestic production.
Vast layers of trapped natural gas
Although oil has dominated the world’s energy portfolio for the past century, natural gas has become an important contributor to the global energy industry.
“While overall global energy demand is expected to increase by 50 percent over the next 20 years – demand for natural gas is projected to increase nearly 70 percent.” [dead link chevron.com speeches/2006/2006-0607_oreilly]
Most, if not all of the available new supply sources will be required, such as Arctic gas, imported Liquefied Natural Gas (LNG), Alaskan gas, Nova Scotian gas, and the dreaded gas from coal.
To meet demand, producers will increasingly turn to gas trapped in sediment and shale. Trapped natural gas – contained in the majority of the sediment – is attracting an increasing amount of attention and the trend is expected to increase. The hydrocarbon volume stored within gas shales is huge and there is a proven economic viability.
Shale gas has a long history. By 1926, the Devonian shale of the Appalachian basin was in commercial production and was the largest known natural gas field in the world.
These shales still account for 21,000 wells in the US.
Whether crude oil or gas, companies have already used various strategies including multiple wells from a single site using directional drilling; sharing leases, roads, facilities and pipelines with other operating companies; constructing centralized facilities. In most cases, these methods will not meet targets.
Technological advances in well stimulation is increasing recovery and improving the economics, but only at higher consumer costs.
Much of the continent’s energy is tightly trapped in sediment. Well stimulation is required for ‘tight’ resources where the paths for the oil or gas to flow are so narrow that without stimulation there isn’t a flow at all.
Injecting water and infamous carbon dioxide – an unusual way of starting to sequester carbon – will force ‘tight’ resources to the surface.
“We are finding it more difficult to tap new, very cheap reservoirs. Vast quantities are bypassed or virtually untapped. Up to 60 billion barrels of oil in the United States could be produced with enhanced techniques.”
Every producing region in the world contains large quantities of potentially recoverable gas and oil. Many more details and background [dead link policypete.com]
And then there’s gas not yet discovered
The USGS [pdf] says it will be found in the areas on this map — along the old inland seas.