Shares in Lansdowne Oil & Gas shot up again on Friday and, unlike last week, when the directors of the company said they were mystified by the sharp price rise, the catalyst for the latest rise is a resource update for the company's Celtic Sea Acreage.In the two oil discoveries in which Lansdowne has an interest, namely Barryroe (20% interest) and Helvick (10%), Lansdowne's net combined proved plus probable (2P, or P50) technically recoverable oil amounts to 12.3m barrels. In its two oil exploration prospects, Amergin and Rosscarbery (Basal Wealden Level), Lansdowne's net combined P50 technically recoverable oil amounts to 80.8m barrels. For the three main gas exploration prospects, Rosscarbery, Midleton and East Kinsale, the new P50 reserves estimate is 331bn standard cubic feet.