Selection of Casings for Water-flooding Development Well

Analyzed are the characteristics staying with damaging of casings used in the water-flooding development well.Based on the analysis, it is pointed out that the key approach to solving the problem of such damaging is developing and properly selecting high anti-collapse casings.Moreover, proposal for specifically selecting high anti-collapse casings is put forward as follows.For shallow wells with depth under 2 000 m, anti-collapse production casings are considered to be used for the reservoir section, water-flooding crack stratum section, and overburden pressure stratum section above the reservoir, or be used through out the entire well; for medium-deep wells with depth ranging as 3 000~4 500 m, selection of casings can be done according to the two major conditions, i.e., production casing well section and various stratum cementing sections;and for deep and extra-deep wells with depth ranging as 5 000~8 000 m, the selection can be made as per the four conditions, i.e., production casing well section, various complex stratum cementing sections, tail casing section, and multi-layer casing strings in extra-deep wells.