Field Application of Newly Designed Non-Damaging Sealing Killing Fluid to Control Losses in Completion and Workover Operations in Western Desert, Egypt

Abstract

Invasion of completion fluids to permeable reservoir formations causes different challenges including increase in water saturation, fine migration problems, well control problems and complicated fluid management. Such problems can result in severe reservoir damage leading to delay in production and increase in operation cost. This paper presents newly designed non-damaging, sealing and killing fluids (Salt Plug) customized to solve such challenges and engineered to control fluid invasion of completion fluid into reservoir. Formation damage might occur during subsequent well workover and perforation operations which requires non-damaging, sealing and killing fluids. The salt plug design incorporates a temporary plugging agent that form a physical barrier across formation face or within formation matrix. Consequently, the plug minimizes formation damage and fluids invasion into reservoir formation during well flow back. Due to its water solubility characteristics, the plug can be easily cleaned up using unsaturated brine water after remedial workover operations. Salt plug was used in reservoir formation in a wide fluid density range of 10.3 - 15.0 Pounds per Gallon (ppg) based on brine type and sized particles concentration to prevent fluid loss during remedial completion operations. This plug was applied in field proving its success in more than 10 deep wells and was successful to seal off void spaces around perforation tunnels and holes up to 0.5 inch. It can be customized to meet project requirements through proper selection of the particle-size distribution (PSD) of salt. Filter cake associated with salt was easily removed with start in production phase with a minimal differential pressure of 20-50 Psi to unload the well. This pill was effective replacing conventional water insoluble calcium carbonate (CaCO3) bridging solids with water soluble sized salt bridging solids which are less aggressive breaker systems.