Abstract
Sound wellbore construction and maintenance are essential to the successful development and production of hydrocarbons from unconventional resources. During the development of a Polish shale play near the Ukrainian border, the integrity of a well under construction became compromised resulting from a breach in an external casing packer on the production string. Successful completion of this well could require fracture-stimulation operations at pressures up to 9,000 psi, which would be impossible, unless the breach could be repaired. A cementing valve just above the breached packer had already reduced the inside diameter (ID) of the 4 1/2-in. production string to 3.827 in. The difficulty of running a casing patch in this restricted environment and the further diameter reductions eliminated this option from being a preferred solution. In addition, the high pressures associated with fracturing operations warranted an innovative solution, rather than a conventional approach. Recently commercialized resins have displayed the ability to withstand stresses higher than 10,000 psi and compressive strains greater than 40% without failure. However, case histories on field deployment of these materials, their ability to be drilled, and performance after hydraulic fracturing were essentially non-existent. This paper presents a case history on the laboratory development of a customized resin solution, the rigless operation using coiled tubing (CT) to place the materials and repair the breached packer, and the drillout after placement. Effectiveness of the remedial operation was determined by subsequent pressure testing. After restoring wellbore integrity, hydraulic fracturing operations were completed and successful production from this well began.
