ROCKMAN wrote: the efforts were solely focused on identifying geologic conditions conducive to accumulating hydrocarbons. As such I have no interest in joining the current debate.
If you'd stuck with the original biotic belief that oil is only found in so-called sedimentary formations then many of today's good basement rock wells would still be undiscovered.
peakoilwhen wrote:all this economic waffle is uninteresting. What is interesting is the geology of ethane. Today methane is accepted by everyone in science to be produced abiogenically in the interior of worlds. When they saw everyone else, petrologists dutifully followed suit and accepted methane was produced abiogenically. The pressure in the mantle is enough to press hydrogen atoms onto the carbon atom.
But that leads to an interesting question, at what point in the HC chain list do fossil fuel believers think that abiogenic processes fail? Rockdoc has a minor heart attack everytime he is forced to use his only argument against abiogenic petroleum : the mantle is too hot so petroleum will break down into natural gas. Break down to what... 100% pure methane? Or is ethane and propane abiogenic too? And if propane, perhaps a tiny bit of butane and pentane get thru too?
What are the hydrocarbon seas on Titan made of? 100% methane? Or is there some ethane there as well?
All in all its a slippery slope, or a pandora's box for fossil fuel believers. Once they open the lid on abiogenic hydrocarbon, there's no going back, and the lid is already open because methane has been ousted as abiogenic. Ethane is next in line.
peakoilwhen wrote:If you don't, then your competitors will get the deep oil and the $millions that could have been yours.
liquid hydrocarbons dominate the reservoir below 6000 m in the Rocket Mountain Basin and the North Caspian Basin. Black crude oil has been produced from the reservoirs deeper than 7000 m in the Tabei Uplift of the Tarim Basin; especially in the Jizhong Depression in the Bohai Bay Basin. Jixian Misty Mountain Formation's Well Niudong 1 at 5639 m produced natural gas and oil amounting to 56.3 × 104 m3/d and oil of 642.9 m3/d, respectively during the production test. In addition, deep buried high-temperature hill reservoirs in eastern China was declared to be found at the bottom of the hole (6027 m) at over 200 °C [8]. The discovery of deep oil and gas in the world has broken through the range of the oil-generating window (60–120 °C) and gas-generating window (0.6%–1.35%) as estimated by early kerogen theory.
China has very few shallow reserves, so they took my advice and drilled deep and, sure enough, found a cornucopia of hot deep oil.
the only thing rockdoc and his ilk want to do if they can't desuade drilling companies from getting the deep oil is to spend a wad of cash trying to find a sedimentary layer a few miles up so they can scream "this is where it came from". It serves no useful purpose at all - Its just money pissed away in a hopeless attempt to preserve a myth from the last century.
Thermal stability of liquid petroleum in the subsurface is closely linked to reservoir temperature. Most oil accumulations occur at temperatures <120 C. Oil cracks into gas at temperatures >150e160 C leading to the dominance of gas condensate and free gas accumulations in ultra-deep high-temperature reservoirs. The recently drilled Fuyuan-1 exploration well (northern Tarim basin) produced high-quality non-cracked single-phase (black) oil from a carbonate reservoir located at maximum depth 7711 m and temperature 172 C.This is the deepest oil discovery in China to date and among the deepest in the world. The oil density (0.825 g/cm3 at 20 C or API gravity 40 ), relatively low gas/oil ratio (135 m3/m3 or 758 scf/bbl), low variety and abundance of adamantanes as well as lack of thiaadamantanes and dibenzothiophenes indicate that the oil was expelled from a source rock at moderate thermal maturity and has not been cracked. The molecular and isotopic composition of oil-associated gases are consistent with this interpretation. We suggest that the oil remained uncracked because the residence time at temperatures >150-160 C was relatively short (<5 my based on 1D modeling) and apparently insufficient for cracking. We conclude that there is potential for finding unaltered liquid petroleum in other high-temperature reservoirs with rela-tively low geothermal gradient and recent burial in the Tarim basin and around the world.
Based on their bulk and molecular composition (Tables 1 and 3; Fig. 6), crude oils from the Fuyuan field have maturity consistent with expulsion from source rocks at temperatures ~140 C and vitrinite reflectance 0.8e1% (middle-upper oil window).
The majority of oil accumulations discovered to date originated from the Middle-Upper Ordovician carbonates, although a couple of oil samples were thought to derive from Cambrian-Lower Ordovician source rocks (Zhang et al., 2002; Mi et al., 2007; Li et al., 2010b, 2012; Yu et al., 2011; Li et al., 2012). Previous studies have shown that oils from the Halahatang Depression are similar to those of the Tahe oilfield and correlate well with the Middle-Upper Ordovician carbonate source rocks in that oilfield (Zhu et al., 2012; Chang et al., 2013a).
1200 C or about 3-4 times higher than the temperature that oil cracks instantaneously in a catalytic cracking unit. Anyone suggesting that oil can survive as a complex chain at those temperatures needs to revisit their thermodynamics.
whereas the temperature at the base of the lower crust is around 1200 C
where you get that from? The mantle-crust boundary can be as cool as 200C. 1200C is the average for half way to the centre of the Earth.
peakoilwhen wrote:
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