RE: Oil Price16 Nov 2018 10:26
OIP estimates - a carrot for investors? (Teacup will appreciate this). It would be interesting to know what is the basis for these estimates without having first drilled a test well. I presume it is based on the Arkex survey carried out before ARKex Ltd went into administration? It will be interesting to see how the future unfolds and how accurate is the estimate of OIP at multiple targets. Do not confuse OIP with reserves as the meaning is not the same.
Knowing you have crude oil or natural gas on your territory is one thing, calculating how big your reserves are is quite another.
Suppose that your geologists have used seismic imaging to pinpoint the likelihood of oil. That's a technique in which sound waves are fired into the ground, and the reflected waves allow the geologists to build a picture of the rock types underground. Oil will usually be found trapped in porous rock formations covered by impenetrable rocks.
So your seismic imaging has indicated promising geological conditions, and you drill an exploratory well. That produces oil, and you think you might have a real bonanza.
Manochehr Takin, an analyst with the Center for Global Energy Studies in London, cautions that this is where things start to get complicated.
"It is important to know what is the size of the oil and gas deposit you have discovered, because when you drill a well into the subsurface and find oil, it's as though you have this huge mass of [material, like a haystack,] and you have one needle, one long needle which goes down and gives you some information, but how do you know the size of this haystack?" Takin says.
Governments can unwittingly or knowingly exaggerate the extent of their resources. The bigger the resources, the more clout the nation has in the world, and the greater the chance of attracting investment.
The experts, according to Takin, have learned to interpret signs. For instance, how thick is the rock layer where the oil or gas was found? What is the pressure of the rising oil, at the bottom of the drill shaft, compared with at the top of the shaft? Does the flow decrease in the hours and days following the strike?
"All these things have to be interpreted, and then you can come up with estimates, and in the end you still only have one well, so other wells have to be drilled, so it is a complicated process, and one can be a long way off [in terms of accuracy]," Takin says.
https://www.rferl.org/a/How_Do_Experts_Estimate_The_Size_Of_Oil_And_Gas_Fields/1330630.html