The theories result and comprehensive technique measure is introduced to improve side entry well cementing quantity,annular clearance of slim hole and casing,micro-step hole enlargement technology,slim hole cementing technology and complement are dissertated concretely.

This paper addresses sidetrack drilling technology in respects of directional sidetracking inside the casing,optimization of annular clearance,slim-hole cementing of reduced narrow clearance,casing failure control for thermal recovery wells and sidetracking with low cost.

Application of turbine-generator air gap monitoring technique;

Study on external insulation of air gap of ±800 kV DC system;

Influence of air gaps in single-layer bandpass FSS structures;

This paper presents the results of DC breakdown voltages of air clearances on typical electrodes at the area with the altitude of about 2000m.

The requisition of improving the air clearance accurancy in the large scale synchronous machine erection and changing configure method are presented.

For this reason, based on the research results in the field of insulation coordination principle for extra- and ultra-high voltage transmission lines and discharge characteristics of external insulation for towers, the author researches and analyzes the air clearance of the towers for AC 750kV single circu.