In general, irregular periods are very common during the perimenopause. The most common early menstrual irregularity noticed in the perimenopause is a shortening of cycle length.
Abiogenic petroleum origin. Abiogenic petroleum origin is a term used to describe a number of different hypotheses which propose that petroleum and natural gas are formed by inorganic means rather than by the decomposition of organisms.
Other Key Byproducts of Natural Gas Processing While natural gas liquids, such as propane and butane, are the byproducts most often related to the natural gas recovery process, several other products are also extracted from natural gas at field or gas treatment facilities.