GUIDE METHOD FOR EQUIPPING BOREHOLES WHEN DRILLING PERMAFROST MINERALS Russian patent published in 1997 - IPC

FIELD: oil and gas production. SUBSTANCE: top part of borehole is widened to the depth exceeding depth at which seasonal and annual temperature fluctuations are still detected to form landing. Stable stepped directed borehole is thus formed, guide is centered and communications - thermometric tubes are placed between the guide and minerals. Drilling mud is partially or completely emptied from borehole prior to be cemented or after the first portion of cement is pumped in and hardened. Then, thermometric means are sunk through thermometric tubes with closed ends and, from measured temperatures controlled are: quality of cementation, stabilization of borehole with guide and guide inserter, tightness of drill string-borehole annulus below the guide in the process of drilling according to guide inserter, heat insulating capability of guide and borehole structure, heat interaction of borehole with frozen minerals in the course of drilling, operation, and pauses. EFFECT: simplified equipping borehole by guide with elevated heat insulating and waterproofing capabilities. 8 cl, 2 dwg