Well Flushing Technology with Drilling Mud in Super Large Diameter and Great Thick Gravel-oulder Formation

Abstract:

The paper introduced the well protection and well washing technology with drilling mud by mechanical drilling construction method; the drilling diameter was 8.3 m, the depth was 286 m and the thickness of gravelboulder was up to 251 m. The preparation of drilling mud, the selection & adjustment of mud performance parameters in different formations, mud purification and well washing were illustrated.

Key words:gravel-boulder formation; superdiameter shaft; mechanical drilling; mud; well protection and well washing