 Summer of '69  is a song recorded by Canadian recording artist Bryan Adams, from his fourth studio album, Reckless (1984). The song was written by Adams and Jim Vallance, a long-time writing partner of Adams.
â¢ UNDULATION (noun). The noun UNDULATION has 3 senses: 1. an undulating curve. 2. wavelike motion; a gentle rising and falling in the manner of waves. 3. (physics) a movement up and down or back and forth. Familiarity information: UNDULATION used as a noun is uncommon.
See: annular velocity, bridge, casing centralizer, cement, cementing, crossflow, displacement, drill collar, eccentricity, flapper valve, pack off. 2. n. [Formation Evaluation]. With reference to invasion, a region between the flushed zone and the undisturbed zone containing a buildup of formation water. The annulus forms during invasion and is caused by the different mobilities of oil and water. It only occurs in the presence of both, but is unstable and will dissipate vertically or horizontally with time. The annulus has approximately the same water saturation as the flushed zone but contains formation water.