The Rising Influence of Rising Affluence

[OakesCS]

If u were confused about the 2 strings of casing, that was probably a bad choice of word. ‘Tubing’ would be more general. Wells are frequently a series of over-lapping tubes with ‘casing’ providing support to keep rock from collapsing into hole. Other tubes and ‘liners’ can be put into the cased hole for varying purposes so tube within tube configurations are common/norm.

As a simple, not necessarily realistic example, a well may have a tube in contact with rock & that tube has been perf’d at 2 locations which are isolated by ‘packers’. A 2nd, interior production tube may penetrate the packers and join the 2 perf’d zones. Later, the production company may decide to go back and perf and stimulate the previously isolated zone but to do so they have to shoot thru 2 tubes to get to the rock.