Causes of and solutions to easy deviation of gas drilling track

Gas drilling can effectively protect low-pressure oil and gas layers and increase drilling speed,which has been widely applied in the area with suitable geological conditions.It is shown that deviation controlling drilling tool assembly and drilling parameters do not perform well in gas circulation drilling,although they are effective in drilling fluid circulation.In this paper,direct and indirect effects of drilling fluid density exert on capacities of building assembly and effect of drilling pressure on capacities of building assembly are analyzed.Anti-deviation measures are proposed for gas drilling.Research shows that drilling speed increases as drilling fluid density decreases.As a result,the sinkage of stabilizers near the bit hence decreases,which leads to greater deviation building capacity.This is the main cause that deviation controlling drilling tool assembly and drilling parameters do not perform well in gas circulation drilling.It is proposed that anti-deviation measures of gas drilling be used for guiding practice.