METHOD AND APPARATUS FOR SEALING AN UNDESIRABLE FORMATION ZONE IN THE WALL OF A WELLBORE

摘要

A method and apparatus are provided for intentionally inducing "formation plugging" in a partially damaged section, water layer, or an otherwise undesirable target zone in the wall of a wellbore. The rigless apparatus is deployed to the target zone by coiled tubing and includes a pair of adjacent inflatable packers or a multi-section inflatable thermoplastic balloon component which is in valved fluid communication with an inflating container filled with formation plugging fluid. The inflating container is in valved fluid communication with a reactant-filled chemical container, the reactant being activated by contact with reactant fluid pumped through the coiled tubing via a circulation valve. The hot pressurized exothermic reaction products pass into the inflation container and displace the formation plugging fluid into the balloon sections and through weakened portions of a central balloon to penetrate the walls of the target zone. The expanded central balloon is melted by the heat of the chemical reaction and a portion adheres to the formation wall thereby sealing the undesirable target zone; thereafter, the remaining balloon sections are deflated or ruptured to permit the apparatus to be withdrawn through the production tubing.