Natural gas and helium producer Renergen’s P12 well, which was previously plugged and abandoned, was observed to start flowing gas (at low rates) in the days following rig release.
The flow rate has subsequently continued to increase with a current flow rate in excess of 30 000 standard cubic feet a day and, most significantly, the measured helium concentration in the gas stream is high at 1.9%.
This well was drilled using standard rotary drilling, which uses water as a drill fluid to remove cuttings during drilling.
Fractures intersected during drilling can drain the drilling fluid, and so Renergen explained on July 12 that it “is common practice” to use lost circulation material (LCM) to seal the fractures temporarily and allow water laden with drill cutting to circulate back to the surface.
When drilling is complete, the LCM typically dries and shrinks; in the case of P12, it appears that it took the LCM over a week to shrink enough to allow gas to flow to surface.
Although initially the flow was at very low rates, the rate has been steadily climbing daily, and is expected to continue to do so until all the LCM has been completely dried out over the coming weeks.
“The significance of this discovery cannot be overstated. While drilling the well was risky, with a low conviction of success, the team did its homework and we decided to drill the well to confirm if this fault is gas-bearing, and more importantly whether it contains helium,” CEO Stefano Marani explains.
“I cannot express how proud I am of the team and its achievements on a five for six drilling campaign,” he enthuses.