What Does
Cast Iron Bridge Plug Mean?
A cast iron bridge plug (CIBP) is a high-pressure plug made of drillable cast iron that can be used to isolate a section of the well. It can be easily set using a pipe or coil tubing or a wireline pressure setting tool. It is highly dependable and widely used in the oil and gas industry.
CIBP is used for well-abandonment, zonal isolation, stimulation, and casing pressure tests. It is available for tubing and casing sizes from 4" to 20" and is easy to drill out due to the cast iron material.
Trenchlesspedia Explains Cast Iron Bridge Plug
The cast-iron bridge plug (CIBP) is considered as one of the most dependable and effective isolation plugs available. It can be permanently set in tubing or casing and is capable of withstanding large pressure differentials and high temperatures. It can easily be set using conventional wireline pressure setting tools. CIBP can be drilled out if necessary, maintaining sufficient strength while it’s set.
It can be designed with shorter lengths to provide a shorter drill out time to save time and cost. It uses setting sleeves and adapter rods and can be set on wireline tool or pipe tubing. The opposing slips are located above and below the rubber packing elements which are contained by back-up rings that eliminate element extrusion at high temperature and pressure. An adequate amount of cement or sand has to be placed over the plug to prevent damage to the plug from perforating shock.
Zone Isolation and Treatment Using CIBP
Using conventional wireline setting tools or tools conveyed via coiled-tubing, the lower zone is perforated, treated, and isolated. Once the CIBP is placed, the lower zone is completely isolated from the other zones protecting that zone from further treatments. It also allows the other zones such as the middle zone to be perforated and treated. During normal treating conditions, the CIBP allows treating pressure above the plug up to 10,000 psi.
Once the middle zone is treated, it can be isolated using another CIBP, and the upper zone can now be treated without affecting the lower and middle zones. Using this technique, all zones in a well can be isolated and treated.
Removing a CIBP
To bring back the wellbore to the production stage, the CIBP has to be removed. This can be done under pressure, in the absence of kill-weight fluids. The removal technology consists of a collection of thru-tubing fishing equipment (mills and motors), remedial or simulation equipment (composite bridge plug), and coiled tubing.
The thru-tubing fishing equipment allows the CIBP to be drilled without pipe rotation. The coiled-tubing conveys mills and motors as a bottomhole assembly downhole to provide maximum efficiency for the drill-out operation.