An approach to rational well spacing for steam soaking development in middle deep heavy oil reservoir;

Two methods for determine rational well spacing in condensate gas reservoir;

The rational well spacing under certain perforating level and the rational open thickness under certain well density can be determined by this equation.

Old conventional ideas should be given up while new ideas should be established:interference among wells is requirement of injection results;reducing well spacing will not affect unit well productivity ;reasonable well pattern and spacing depend on injection ability of a injector;well pattern controls "flow system" not "oil sand bank".

Determination of grid interlayer rational position in asphalt overlay structure

The rational position of roadway was put forward and has been applied successfully in roadway driving of fully-mechanized top-coal caving face 5318.

Based on the educing of the minimal capsizing moment and the minimal earth pressure by Rankine’s earth pressure theory,the rational position of retaining wall relieving board was found:the upright distance from relieving board to the external surface of filling soil is one-third to one-second times of retaining wallh ighness.