<P> Many major security companies take part in securing the industry . </P> <Ul> <Li> Other: </Li> </Ul> <P> Any other oil and gas related business not defined above . </P> <P> In ISO 20815 define Upstream in definition section as: 3.1. 48 upstream business category of the petroleum industry involving exploration and production . </P>

What is oil and gas downstream upstream and midstream