Theoretically, in vitro fertilisation could be performed by collecting the contents from a woman's fallopian tubes or uterus after natural ovulation, mixing it with sperm, and reinserting the fertilised ova into the uterus.
Upstream operations deal primarily with the exploration stages of the oil and gas industry, with upstream firms taking the first steps to first locate, test and drill for oil and gas. Later, once reserves are proven, upstream firms will extract any oil and gas from the reserve.
Term used to refer to the part of the oil industry responsible for the sales and delivery of oil and natural gas products. see also upstream. We needed to go further downstream because I thought I saw something there earlier that would give me a nightmare.