"Fossil fuels"
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Try researching kerogen for about 5 min. Every time this comes up I roll my eyes.
I have a MSc in geology and 20+years experience as a petroleum geologist. I have spent my professional career studying petroleum basins and drilling oil wells. If you have questions, I’m happy to share to try and combat the utter ignorance.
Added bonus, my wife is a drilling and completions engineer for a big oil company. I won’t say who we work for as they are publicly traded.
https://en.m.wikipedia.org/wiki/Kerogen#:~:text=Kerogen%20may%20be%20classified%20by,e.g.%2C%20pollen%20and%20spores).
I tried to reply 2x on my ipad and it froze. trying again from desktop. hope i encapsulate my previous. i want to make 3 points, namely, kerogen maturity, historical narrative, future outlook.
kerogen is much more than shit. you're being salty, i like it. studying kerogen, we can predict what hydrocarbons will be produced. more woody...gas. more algal...more oil. that being said, there is a temperature-pressure relationship. important for economic calculations. It has to do with elemental ratios of what is preserved through oxidation.
https://imgs.search.brave.com/_ESA76eKCeB9qe6hFW97g7HgZX8wew6Pz7OkXaYC5zs/rs:fit:430:225:1/g:ce/aHR0cHM6Ly90c2U0/Lm1tLmJpbmcubmV0/L3RoP2lkPU9JUC5w/cVRvTk9Zc0Q2ZzVV/S3owZXllVHNnSGFJ/SyZwaWQ9QXBp
https://en.wikipedia.org//wiki/Kerogen
with depth of burial and increased temperatures this creates an "oil window" and "gas window". with increased depth and increased temperature we can drill, in oil areas, for gas wells. alternatively, we can seek the temperature source (tectonic; see west texas delaware basin) and drill gas wells at the same depth but drill gas wells. I can point you towards literature that shows this. this affects LPG yields and economics.
https://www.researchgate.net/profile/Robert-Ross/publication/322641749/figure/fig4/AS:613903448936461@1523377396612/Diagram-showing-how-the-formation-of-oil-and-gas-depend-on-temperature-and-pressure.png
I can get into the details, but modern oil/gas leases only cover the deepest productive rock. older leases do not. pugh clause.
let's take a step back. 100 years ago we only drilled the best shit. now, we are forced in to drilling pretty crappy rock. crappy rock that the ppl from 100 years ago would not have imagined. all of their equations break down. this is the shale revolution. that does not mean it is unexhaustive. but a calculation is made on how deep to target for a lease. the deep rights may expire.
let's go back to kerogen. the old model was source rocks (rocks deposited during oxygen-starved times (think woodford formation)) produced oil, which migrated to petroleum traps. circa-2005-08 we migrated to a new model where we target the source rocks, under active hydrocarbon generation, that's the new target (accelerated ~2017 ((my involvement))). So now we drill the rocks actively generating hydrocarbons (think Wolfcamp).
What we monitor? Pressure relationships from nearby wells. Rinse-n-repeat the pressure depletion. How do we get an extra few % recoverable?
it's all about economics. a good recovery factor for a many reservoirs is 40%. and that's after waterflooding. waterflooding is a process of injecting water from surface to maintain the reservoir's pressure. not all reservoirs are good enough to economically do this.
so natural pressure depletion is called primary production. waterflooding is one method of secondary recovery.
now, what is tertiary recovery? let's stick to oil and forget gas for now. as you decrease the oil saturation (through production), the relative permeability to water (the wetting phase) increases. at some point you reach an economic limit, because it costs money to pump the fluids to surface, etc. that is when wells get shut in, plugged, etc. but there is still recoverable resource in the reservoir.
i once worked on a project (15 years ago) where we pumped soap into an underground reservoir. same as washing your hands, right? if oil stayed at a high enough price for long enough, this technology would unlock vast amounts of recoverable oil. we got local recovery factors exceeding 90% of OOIP on that pilot project.
resource vs reserves https://en.wikipedia.org/wiki/Mineral_resource_classification
Blasingame fanboi https://www.youtube.com/watch?v=GIORNcSUbD4
EOR https://en.wikipedia.org/wiki/Enhanced_oil_recovery
ASP flooding https://onepetro.org/SPEEURO/proceedings-abstract/17EURO/2-17EURO/D022S014R003/194812
So, is petroleum a fossil fuel or not?
Catagenesis
So ... are you supporting or refuting the OP's image of a tweet over the idea that petroleum is, in fact, super plentiful, abundant and forms quickly?
Plentiful but not renewable. Does not form quickly. The chat about wells filling back up is based solely on economics. The oil and gas industry is very capital intensive.
So there's deception on both sides of the issue. The wells weren't "filling back up" ... the surrounding petroleum was refilling the reservoir that the well had tapped.
lack of understanding
we shut in wells, if they are not making money. we are forced, by regulatory agencies, to plug wells after a certain time of inactivity. why would we try to displace the time to plug a well? it comes down to economics.
wells/land/ownership, in the US, are leased from private/federal owners. generic law is that as long as it produces (at economic quantities), the lease is held under the original documents. if it is uneconomic, the lease becomes invalid. the lease is released. think PUGH clause. so one well, containing a lease acreage greater than attributed to one well, can maintain a lease. i can produce a well for a couple barrels a month to keep a lease that maintains a lease of 40 acres, or 320 acres. depends on how the original documents were drafted. no conspiracy, just business and evolution of contract law. remember that lawyers were drafting lease documents from the seat of their pants 100 years ago.
wells tend to produce, initially, by depletion drive. not all. there are other drive mechanisms. this affects what the expectations on recovery is.
if you only recover 10% of the original oil in place (OOIP) through depletion drive, why would you spend a bunch of money if there are potentially ways of recovering additional oil? economics. and yes 10% is a reasonable expectation globally average for depletion drive reservoirs. look it up. it's greater for a water drive.
that's what i do. what is the recovery? what can we do to increase the recovery? is there meat left on the bone. there are many different methods to enhance recovery, but they are cost-intensive.
it's not deception, really. it's a misunderstanding of what is possible, economically.
let's talk about 2 key concepts. 1; what is available original oil in place (OOIP) and 2; what rate can it be delivered (Darcy). this drives what is known as rate of return (ROR) and expected ultimate recovery (EUR). two vastly different calculations, based on a time function, due to the time value of money (cost of capital).
So...when the pressure has been drawn off of the reservoir, and deliverability is reduced, what is left. How can we get it?
We do that through secondary and tertiary recovery. These are know as waterflooding and CO2 flooding. others are polymer and surfactant polymer flooding. There are others.
So, if you have a well that comes in at a certain rate, it will decline as the resource is drained. At some point, it will decline to a point where it is uneconomic to operate and make money. Then, we evaluate whether or not we can manipulate the rock to recover more oil/gas from the rock. This is driven by economics.
https://wiki.aapg.org/Reserves_estimation
https://en.wikipedia.org/wiki/Darcy's_law