Drillinginfo Inc., an Austin-based company that makes digital tools for oil companies, has been acquired by Genstar Capital LLC, according to a Tuesday announcement by the San Francisco-based private equity firm. Genstar did not disclose financial terms. Drillinginfo had been majority owned by Insight Venture Partners LLC, a New York-based venture capital and private equity firm, since 2012. Insight will maintain “a significant minority stake,” the announcement said.