THE CASING PROGRAMS FOR THE TROUBLESOME DEEP AND ULTRA-DEEP WELL

The casing programs applied in our petroleum industry at present is single and has no enough casing intervals to insulate more troublesome formations, and it cannot meet the requirements of deep and ultra-deep well drilling in troublesome geological conditions. In this paper, the ways to increase the casing intervals in casing program design are discussed, e.g., increasing the upper hole and casing size, applying slim hole drilling technology, using non-joint casing and reaming bit, and optimizing the matching between casing and hole size, etc. Six new types of casing programs are proposed, and these new programs may be helpful to the troublesome deep and ultra-deep well design.