Massive data exists in Well-Engineering domain, and they are distributed or heterogeneous. These features lead to difficulties during data integration and global decision making. For this problem, this paper proposes a solution of building virtual data center by means of semantic integration technology. In this method, schemas of data sources are firstly mapped to semantic views on domain ontology, secondly, with translation algorithm, global semantic query is rewritten into series of SQL statements which will be dispatched to relevant data sources and executed on local sites, finally, query results are reorganized and submitted to users. By practical application, this virtual data center can supply semantic-based data support for well production decision.