In geological survey well engineering for CBM resources investigation and evaluation project in Miaoergou area of Changji of Xinjiang, the designed well depth was 2500m, and full borehole coring was required. There are problems of difficult coring, leakage, hole shrinkage and winter construction. By adopting special coring tools, enlarging bit outer diameter and annular clearance, heating with oil heater and some effective measures, the difficulties in drilling technology and logistics supply are effectively solved to provide data for CBM resources investigation and evaluation in this area.