Technical Difficulties in Large Diameter Well Drilling in Coal Mine Construction and the Countermeasures

Abstract:

Based on a well drilling engineering of a mine in Shandong, the paper introduced the advantages and difficulties of construction without surface casing drilling with the countermeasures. The construction of 2 wells were fulfilled ahead of time through deviation control by tower drilling tools, inclination survey by gyro inclinometer, wall protection by high-quality mud and working intensity reducing by buoyancy device and impact wrench. Drilling without surface casing greatly saved the construction cost.

Key words:large diameter well; no surface case; construction difficulty; countermeasure