By OGJ editors
HOUSTON, Aug. 24 -- Calvalley Petroleum Inc., Calgary, has named David Tkachuk to senior vice-president and managing director of Calvalley's Yemen operations.
Tkachuk will oversee all of the company's international exploration and development activities in Yemen. He brings 25 years oil and gas experience to Calvalley.
Before joining Calvalley, Tkachuk was a senior officer of Nelson Resources Ltd. and director general of Nelson's joint venture project in Kazakhstan.
Calvalley succeeds David Winter, who has resigned to pursue personal interests.
