We are one of the largest providers of contingent/contract personnel with expertise in the upstream oil and gas sectors. NTGV, with the merger of Sierra Hamilton, has a 50 + year history and has developed a well-established network of more than 44,000 contractors who manage critical aspects of our customers’ most challenging projects. NTGV is a trusted partner to multinational oil and gas corporations and independent exploration companies with more than 350 active master service agreements.