GDN golden state resources limited

snagg...My understanding is the pumps effectively increase the...

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    snagg...

    My understanding is the pumps effectively increase the pressure on the formations relative to non-circulating muds, due to viscosity, friction and other hydrostatic effects.

    Further, the pressures at these depth result in the drilling mud flowing into the formations rather than the other way around, leaving mainly "drilling gas" (the gas released from the breaking of rock at the drill bit), to enter the mud for readings.

    To prevent the continuous inflow of drilling muds into the formations, various additives are introduced such as bentonite clay, which apart from helping to remove cuttings from the well, formas a filter cake on the walls of the hole...effectively creating a "skin" on the outside of the well bore (against the formations)...inside which the muds circulate.

    The pressure on this skin, whether the mud is circulating or not, is such that for gas to enter the bore, it must be at a higher pressure than the skin being applied to the well bore?

    Well at least this makes sense to me?

    As for flowing up the entire formation...the well is cased to 15,397ft...so the only gas entering the bore should be coming from these highly pressurised mud depths over the last 756ft (230m) of drilling.

    Of this now exposed hole, (uncased section), just 176m is actually in leadville according to the last announcement.

    Finally, my understanding was that trip gas does not actually "rise to the well surface" during pump shut-in unless significantly pressured relative to the muds. That when the pumps are shut, the gas simply enters the mud (if it can), in the area immediately exposed to the formation and then just pretty much sits there suspended due to the additive characteristics...unless of course the gas pressures are greater than that being applied to the "skin", resulting in continuous flow of gas to the muds and eventual forcing up of gas to surface.

    I believe this is why "trip gas" is only measured after the pumps are turned back on and those sections of mud returned back to surface...and also why the readings are typically higher due to the time the muds have sat against the formations?

    I am by no means an expert in this, so could well be wrong, but with a skin effectively forming on the well bore and pressures on this skin near 7,000psi (assuming 9ppg drilling mud SG)...any gas influx at all suggests significantly pressured gas exists?

    Of course, it says little about the potential for the gas to flow in "open hole" conditions (without drilling muds), which is why I await post drilling prognosis with a degree of anticipation.

    I really wish the company would add some commentary on this formation pressure issue relative to background and trip gas readings.

    Cheers!
 
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