It’s not often I get to nerd out over oil and gas using my igneous petrology background, so imagine my childlike glee in finding an article about oil in porous intrusive rocks! I cannot articulate the restraint it is taking to focus on the oil and gas part of the story rather than fractional crystallization profile that indicates a shared enriched mantle source and/or crust-magma interactions. 🤓 Let’s take a look.
Sarah Compton
Editor, Enspired
This Company Hopes to Use Giant Microwaves to Drill the Deepest Hole Ever
Somsak Nitimongolchai/Shutterstock.com
The hardest part about accessing geothermal heat sources is the same reason we’re going after it in the first place: It’s hot!
The problem: Drill bits are generally comprised of materials that don’t do well in extreme heat.
One way to sidestep that is to remove the bit from the equation, but how do you get a hole without a bit? Vaporize the rock with microwaves, obviously!
A new solution: A company called Quaise Energy, which I’ve mentioned before here, has developed a dual-method technology combining traditional drilling with millimeter wave drilling. It’s currently field testing.
How it works:
The company is using a gyrotron to blast through the rocks at depth.
A gyrotron is a giant microwave that generates millimeter waves—i.e. high-frequency radio waves. The gyrotron was invented by the Soviets in the 1960s.
Gyrotrons are now commercially available and can be found in fusion-energy research laboratories where they’re used to heat plasma.
Quaise deploys a “waveguide” to direct the waves through a pipe that shapes them into a beam of energy.
It relies on crystallized, vaporized rock and circulating nitrogen gas to act as a glass encasement, so to speak. This might be how Quaise plans to prevent blowouts and/or collapse.
#Goals:
Those aforementioned Soviets drilled the deepest hole on Earth back in the 70s, where it took them two decades to make it down 7.6 miles.
Quaise plans to surpass that depth in the next few months, using conventional drilling to go 1–2 miles down, then switching to its one-megawatt gyrotron, which will be able to vaporize 11.5 feet of rock per hour.
The bottom line: As a geoscientist, I think it’s really cool to dig deep and find geothermal heat sources, but I have a feeling data collection while drilling (e.g. gamma or other petrophysical measurements) is either not a consideration or an obstacle that needs to be overcome—likely with our input!
Pipeline Design Plays Critical Role in Transboundary CCS
Transboundary CCS plays a key role in decarbonization strategies for countries with a significant number of industrial emitters but limited domestic storage, particularly geographic zones characterized by earthquake epicenters, volcanoes, and tectonic plate boundaries.
When you see the words “oil and gas reservoir,” they evoke images ranging from beautiful and high-porosity sands, to extremely tight shales with salts and tar sands in between.
Intrusive igneous rocks typically don’t come to mind, unless those rocks have been highly fractured or pulverized essentially into a sand… until now.
New discovery: A well drilled in Block 56 in southern Oman had oil shows in a series of Late Neoproterozoic alkaline intrusives in the Huqf Supergroup.
The igneous bodies occurred as discrete and composÂite sills on the scale of tens of meters, separated by intervals of Huqf host rocks.
Researchers recorded porosities in excess of 10 percent in the intrusives, and it’s thought such porosity was created via dissolution, as the primary ferromagnesian minerals were converted to biotite and ferroan dolomite.
A short-lived Cretaceous hydrothermal vent—which was fault controlled during uplift caused by alkaline volcanic activity—is thought to be the driver for the dissolution.
One challenge: Porosity is one thing, but to have a viable reservoir, you need permeability also, and alas…no permeability measurements have been taken of the rocks…yet!
Why it matters: This situation warrants some watching because the path forward here has so many opportunities for geoscientists of all backgrounds.
As mentioned above, the permeability of the rocks is going to be a key characteristic to determine if this could be an economic reservoir.
The timing of events needs a bit of polish. There’s sourcing and emplacement of the bodies and effects on surrounding rocks. There’s also fractionation, migration, and cooling of the igneous rocks.
Then, there’s uplift, interaction with the hydrothermal vents up to the north, and ultimately generation and migration of the oil into the rocks—plus how that might impact the overall geochemical profile.
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