In the petroleum and natural gas sectors, large vertically integrated multinationals engaged in the extraction, refining and distribution of oil and gas products contract out (see box 1) the services that they need in order to find, develop and deliver oil and gas, such as the initial determination of likely sub-surface reserves, drilling services, derrick erection, well casing, specialized construction services to build pipelines and refineries, and services to remove impurities from oil and to liquefy and re-gasify natural gas.
在石油和天然气部门,从事石油和天然气产品的开采、提炼和分配的纵向联合大型纵向联合跨国公司把它们探测、开发和提供石油和天然气所需要的服务承包出去(见框1),例如可能的地下储藏的初步确定、钻井服务、井架架设、钻井套筒、建造输送管和炼油厂的专门建筑服务,以及消除石油中杂质和天然气液化和重新气化的服务。UN-2 UN-2