** Shares of Grand Gulf Energy GGE.AX rise as much as 30%
to A$0.013, their highest since Dec. 11
** Stock posts its biggest intraday percentage gain since
Dec. 11
** Gas explorer says flow testing showed helium gas flowing
to the surface with high helium concentrations at its Red Helium
project in Utah, U.S.
** More than 21 mln shares change hands, versus the 30-day
average volume of 4.4 mln
** Stock down ~47% this year, as of last close
(Reporting by Aaditya Govind Rao)
((Aaditya.govindrao@thomsonreuters.com;))