Research on oil-based plugging technology in a horizontal well section of the Fuling shale gas field

Abstract

To address the serious issues of leakage, challenging plugging, and significant friction related to the long horizontal section construction in the Fuling shale gas field, a study was conducted to develop a suitable leak-proof agent OBMCP for oil-based drilling fluid. The difficulties of preventing leakage and plugging oil-based drilling fluid were analyzed, and the amount of reactively consolidated polymer HY-1 was controlled at 6.25 – 7.5% while considering the plugging strength requirements and plugging costs. The enhancer ZQJ was controlled at 0.4 – 0.6% to achieve high-strength rapid plugging, and the gelation time was controlled under the premise of safe construction to achieve a controllable curing time. Consequently, the oil-based drilling fluid leakage prevention and plugging technology were formed and applied in the J1 and J2 wells. The field test showed that the optimized drilling fluid had stable performance, a good plugging effect from the consolidation plugging agent, a stable borehole wall, small leakage, and strong anti-pollution ability, thereby achieving high-strength rapid plugging and a controllable curing time.

Keywords

• oil-based drilling fluid
• plugging while drilling
• consolidation plugging agent
• wellbore instability
• fuling shale gas