Isolation of Zones for Fracturing Using Removable Plugs

摘要

An interval can be divided into zones by inserting a series of plugs that register with specific profiles at predetermined intervals along a section of pipe. Each plug supports a releasable perforating gun that can release from the plug and perforate an interval for treatment such as fracturing or acidizing. A subsequent plug then isolates the just treated zone and the process is repeated working up toward the surface. When the full interval is treated the plugs can then be removed by making their cores disappear using a reaction or dissolving techniques. Mechanical alternative that push all the plugs to hole bottom or that retrieve them together or individually are possible alternative techniques for removal of the plugs from the treated interval before production is initiated.