DESIGN AND RESEARCH OF COALBED METHANE THERMAL INSULATION AND PRESSURE PRESERVING CORING TOOLS

摘要

A new hydraulic reverse pressure system, temperature-measuring pressure gauge assembly and measuring instrument, and nitrogen pressure compensation assembly were developed. A detachable aluminum alloy vacuum insulation tube and a pressure-preserving core ball valve assembly were designed. Strength check and calculation; corrected temperature and pressure effects, analyzed the interaction between internal temperature, pressure and core composition under external environmental changes; achieved pressure and temperature maintenance during core drilling, and reached design requirements.Completed the on-site experiment of the coring tool, accumulating 36 cylinders, holding pressure of 33 cylinders, holding pressure success rate of 91.67%, experimenting and verifying the various systems of coring tools, through field experiments, holding pressure on insulation. The construction process, core cutting process, data processing technology and pressure operation process of the coring tool have accumulated experience.