The harder the oil is to extract, the bigger the rewards for the oil-service companies.
石油越难提炼，油田服务公司获利就越大。
2
He was once its finance director, and has private-sector experience. His job will be to pilot the negotiations with private oil-service firms.
他曾任Pemex金融部经理并有私部门经验，主要工作是要带头与民营石油服务公司进行谈判。
3
But the oil-service firms will get only the book value of their assets, paid in government bonds and with deductions for any labour or environmental liabilities the government adduces.