Enhance Light Workover Operation Performing B Annular Through Tubing Plug and Abandonment

Traditional well plug and abandonment (P&A) operations often use rigs to remove the completion string and sometimes the production casing to establish necessary barriers. However, this approach can be costly and complex. An alternative method involves light intervention techniques that avoid the need to remove the completion string and casing. This allows operators to seek alternatives to bypass section milling and other invasive procedures, enhancing safety and operational efficiency while reducing costs. This paper introduces an innovative solution for optimizing P&A operations through riser-based light well intervention systems, specifically focusing on through-tubing B-annulus isolation. The proposed method involves a carefully planned operational sequence to place and verify A-annulus cement, followed by perforating to reach the B-annulus. This involves piercing through the tubing, A-annulus cement, and 9 5/8" casing without damaging the 13 3/8" casing. An experimental setup is created using 6-foot-long production tubing placed inside a 9 5/8" casing, which is then cemented. These components are subsequently placed inside a 13 3/8" casing and installed in a test set up. Water fills the remaining annular spaces, and selected charges are fired within the tubing from the bottom hole assembly (BHA). This setup helps choose the appropriate BHA design and ensures that cement placement occurs exclusively within the B-annulus. Additionally, computer simulations are conducted to tailor the slurry and washer rheology, further ensuring successful field operations.