METHOD AND DEVICE FOR THERMAL INSULATION OF MOUTH ZONE OF PRODUCING WELL IN PERMAFROST GROUND Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: this relates to operation of producing wells in cryolitic zone and is intended for keeping ground around mouth zone of well in frozen condition during its entire service life. According to method, placed around upper section of pipe string is thermal-insulating component. Installed over entire length of this component are heat-transmitting pipes or containers. Effected by these pipes or containers is heat removal from thermal-insulating component. Installed into pipes or containers directly after guiding pipe are seasonally operating thermal stabilizers which can be extracted and replaced. These thermal stabilizers carry out transfer of natural cold from atmospheric air to boundary between thermal-insulating component and permafrost ground. Number and relative positioning of pipes or containers and thermal stabilizers around perimeter of guiding pipe is determined by solving two-dimensional non-stationary heat transfer equation. Calculation area is represented by segment of cross-section which is parallel to ground surface. Extension of calculation area can vary from 1x1 m to 30x30 m. Pitch of division to elementary units is non-uniform and can vary within 0.01 - 5 m. Application of aforesaid method and device allows for maintaining stability of producing well, ensuring reliable fixing of bore-hole in mouth zone of well, with saving energy due to utilization of natural cold air from atmosphere. EFFECT: higher efficiency. 5 cl, 2 dwg