Shares in oil development and production company Nighthawk Energy gushed higher Monday after an upbeat trading update revealed a significant increase in estimated oil in place at the Cherokee and Atoka shale formations on its Jolly Ranch prospect.The company said that the reservoir simulation model of its Jolly Ranch prospect has put the oil in place per acre in the target within the simulation study area at a level some 14 times higher than previous estimates."Ultimately, this higher estimate should also result in larger recoverable resources as the significant upgrade in oil in place within the Cherokee and Atoka shales more than makes up for the study area's unproductive conventional Marmaton horizon," said broker Westhouse Securities."The simulation study further underlines the potential of Jolly Ranch; however, operational work remains to be undertaken in order to demonstrate that oil can be economically and consistently recovered from the field," said Tim Heeley, chief executive officer of Nighthawk. The study report has been passed on to Gaffney Cline and Associates who have commenced the reserves and contingent resource report.