In the horizontal well of long and middle radius, the drillstring of several thousand meters is in random contact with the bore hole wall in a large area along the well depth, which is a nonlinear contact problem.

A large bending stress appeared when the casing passed the bending part of a medium/short radius horizontal well with a big curvature,which reduced the permission compressive strength of casing leading the failure.

Simulation on the influencing factors of bending steering mechanism used in radial horizontal wells;

Research of simulation on steering mechanism used in ultrashort radius radial horizontal wells;

A study of non-radial expand of production tube in radial horizontal well;

By simulation of the drip irrigation technology in mulched cultivation, pointinfiltration experiments are performed under different temperatures, and the influences are analyzed of the temperature on the shape of wetted soil, horizontal wetted radius, vertical wetted depth, and water content of wetted soil.