An Improved Oil-Based Chemical Gel System for Wellbore Stabilization

摘要

Historically, water-based chemistries, such as epoxy resins, latex polymers and transition metal crosslinked polymers have been used to mitigate many of the operational problems associated with formation fractures. However, these approaches have found limited success for various reasons such as temperature limitations, complicated mixing and placement issues, weak gel strengths, health & safety concerns, and compatibility with various types of drilling fluids. A new oil-based chemical gel system which addresses many of the issues associated with current systems has been developed. The thermal stability, curing time, compressive strength, and adhesion properties of the new system depend on the manipulation of the composition and chemistry of the components. This newly developed chemical gel is more controllable over a wide range of temperature and time, and is compatible with many invert-emulsion drilling fluids. This paper will detail the innovative chemistry of this oil-based gel system. The gel is formed by the crosslinking reaction of a modified polyurethane resin and a uniquely modified siloxane mechanism. Systematic development and evaluation, including temperature stability, controllable curing times, compressive strength and adhesion strength to formation of the system will be included.