A New Retrievable Wire Line Cementing

This paper describes a new retrievable wire line cementing tool, its field operation, well applications, well conditions, and performance data. The cementing tool is "run" into a well on an armored electric cable in the same manner as a conventional perforating gun. The tool utilizes gases from the burning of a high energy propellant to expand a rubber packer against either casing or an open hole section. Further expansion of gases shears an aluminum retaining plug from the bottom of the cement container, forcing cement into the desired position. The complete tool with the exception of the small aluminum plug and gun seal is retrieved from the well. Additional cementing"runs" may be made for additional cement fill. This wire line tool has been used successfully to eliminate bottom-hole water from an open hole section, to squeeze cement either a complete or partial set of perforations, to squeeze leaky casing shoes, to seal leaky bridging plugs, and to seal channels in the annulus. Introduction In the past few years with deeper drilling and new well completion techniques, the cementing of oil wells has become a more highly developed operation with specialized equipment and trained personnel. During primary casing cementing operations, neat cement is placed in the annulus to accomplish any or all of the following:Separate formationsSeal formation for deeper drillingForm a support and protective cement sheath around the casing Squeeze cementing may be defined as a secondary cementing operation in which cement or other sealing material is forced into an open section or into perforations to obtain a seal or a "shut off" of undesirable fluids or gas. The quantity of cement usually necessary to actually seal perforations, channels, and voids, or to successfully seal an open hole section has generally been found to be relatively small. It is necessary only to fill the desired channel or perforations with cement, allowing it to harden in position. The problem is to place the cement where it is needed, and with conventional methods, this sometimes requires many times the amount of cement actually needed for sealing.