Dear Mr. De,

radon has per se nothing do with HC plays; it is a decay product of the U-238 series. As gas it is a good marker for deep-seated structure zones. On the other hand U can be accumulated in its tetravalent state in reducing environments as it is the case with HC plays, a fact also used for capturing digital data by means of gamma spectrometry in the field or gamma tools in wireline logs. But I would like to voice a stark warning as to the so-called uranium disequilibrium which is of utmost importance in systems of low U concentration and younger than 800000 years. A simple alpha survey devoted to radon without a proper knowledge of the local geology, particularly structural geology will provide you with an uncertain database. The entire decay chain is subject to variation in solubilities and redox conditions, e.g., U-238 shows a low solubility, Th-234 = low solubility, U-234 = high solubility (> U-238).....Ra-226 = very low solubility, Rh-222 = very high solubility....Bi-214 = detected by the gamma counter. It is a scientific discipline of its own as exploration geologists in the uranium business will experience during field work.

Good luck

H.G.Dill

Thank you so much Harald Sir. Pardon me, I am just a student. Don't have much idea. But I have read some publications like -"RADON MEASUREMENTS USING SSNTD IN THE REGION OF OIL AND GAS DEPOSITS 0F WEST TURKMENISTAN "

Author: .ISHANKULIEV and S.P.TRETYAKOVA

I want to know firstly that the concentration of radon is not reducing as the reservoirs are at deeper depth? And in what circumstances, in radiometric studies we use radon measurement over gamma radiation monitoring?

I also have one separate question, I am trying on my side to find out i.e-

How much radon (concentration) is produced from say 50ppm of uranium? I want the governing equation to find this out. On long search I found one which relates with activity. But it doesn't discuss much till the third stage of the decay chain. I, need to know this to understand the full phenomenon of radon halo. I again request you to please excuse me if I am bothering you. Thank you once again.

I think, it is preferable to use radon concentration to explore earthquake rather than petroleum exploration,  because radon can be produced from the uranium decay series,  and this process  need no more depth,  may be occurred near the surface.  Furthermore.  Rn can form from phosphatic fertilizers that added to the agricultural land.  Thanks for all

Sde,  My response relates to sub-surface, but I hope that it helps. As far as subsurface measurement go, I am not aware of Ra being specifically measured down hole.  Usual GR spectrum measurements focus on K, Th and Ur as the main contributions to the GR measured signal. K has a single, distinctive, 1.46 MeV decay signature, but Th and Ur have very much more complex decays. The Ur decay includes the Ra group. So Ra is considered as part of what is called the Ur-Ra decay, that makes up the Ur measurement.  Bateman (Open-Hole Log Analysis and Formation Evaluation) has a pretty good explanation of this, if you are interested in how this works. The decay 1/2 life you mention is actually very much more complex.  But the point is that Ra itself is not - normally - measured as part of the GR spectrum logging.