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.
Downstream sector. The downstream sector of the oil and gas industry involves the refining of the crude oil and/or raw natural gases obtained in the upstream sector as well as selling or distributing the products obtained.he downstream sector of the industry is the sector that relates with the consumers. Facilities involved in this sector include petrochemical plants, oil refineries, natural gas distribution companies, retail outlets and so forth.