Kentz co-founder Noel Kelly helped develop the Tipperary-based oil services firm into a global player in the energy contractor sector. He sold 16m worth of shares after the company floated. When he left Kentz, he had 3.4m shares in the firm. It was subsequently bought in a 1.68bn deal. Kelly now invests in start-ups including innovative waste water treatment firm OxyMem. In 2015, he invested in OxyMem through Kellysan, his family-owned private equity firm.