气体钻井轨道易斜原因及对策

气体钻井能有效地保护低压油气层和提高钻进速度,在地质条件适合的区域获得了比较广泛的应用。实践中发现,钻井液钻进时的有效的防斜钻具组合和钻进参数在气体钻进时,效果不佳。分析了钻压、钻井流体密度对钻具增斜能力的影响。研究表明,钻井流体密度降低使钻进速度增加,钻进速度增加使近钻头稳定器下沉量减小,近钻头稳定器下沉量减小导致增斜能力增强,是钻井液钻进时的有效的防斜钻具组合和钻进参数在气体钻进时效果不佳的主要原因。提出了气体钻井的防斜措施。

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.