Shares in Roxi Petroleum jumped 20% early on Monday, as the oil and gas explorer provided operations update at its flagship BNG asset.The Kazakhstan-focused group said that the blockage at the A5 discovery well on the project had been removed and the 30-day flow test was expected to begin in the middle of June, while core samples at Deep Well 801 revealed a potentially oil bearing interval starting from 4,536 meters.Meanwhile, the London-listed company said it had completed the first phase of the Galaz asset sale to Xinjiang Zhudong Petroleum Technology Company.The China-based group has paid $58m (£38m) to LGI, which owns 40% of the site, while Roxi is scheduled to receive its share of the payment in the second phase of the agreement, which requires a separate Chinese exchange control approval that is expected to be granted during early June.Roxi and Xinjiang Zhudong have agreed to extend the date for completion of the Galaz sale to 12 June, when the AIM-listed group will receive approximately $23m.Analysts at WH Ireland Research described the development as "pleasing", adding they reiterated their 'buy' rating on the stock."We are pleased with the operational progress Roxi has announced today," they said in a note."We look forward to the 30-day flow test at A5, which we believe is a key catalyst for Roxi's share price in the near term."Roxi shares were up 17.87% to 16.35p at 10:39 on Monday.