低压脉冲空化射流复合钻井技术

A Comprehensive Drilling Technology of Low-pressure Pulse and Cavitating Jet

低压脉冲空化射流复合钻井技术是在钻头与钻具组合之间安装一个低压脉中空化射流调制装置,通过其对射流进行调制,产生脉动低压改变井底岩石的受力状态,降低抗破碎强度,提高钻头机械破岩效率,同时变常规连续射流为空化射流,增加井底水力破岩和清岩效率,进一步提高深井钻井速度。塔河油田现场实验结果分析表明,实验井段5 349～6 162 m,纯钻时间为129.36～136.63 h,低压脉冲空化射流调制器工作正常,与临井相同井段对比,机械钻速平均提高40.6%～85.1%。

A comprehensive drilling technology of low-pressure pulse and cavitating jet is to install a modulation facility of low-pressure pulse and cavitating jet between drilling bit and bottomhole assembly.In the technology,jet may be modulated to generate low-pressure pulse further to change the forced status of bottomhole rock,to decrease the anti-crushing strength,to increase the efficiency of breaking rock,meanwhile to change the conventional continuous jet into the cavitating jet,to increase the efficiency of hydraulic breaking and cleaning rock of bottomhole,and to increase the drilling rate of deep wells.An experiment of Tahe oilfield shows that the tested well interval ranges from 5349 to 6162 m,the drilling time varies from 129.36 to 136.63 h;and the modulation facility is in a normal work;compared with same interval of adjoining well,the penetration rate is increased by 40.6～85.1%. Through the technology,the drilling rate of deep wells in Tahe oilfield can increase a lot.