水力脉冲空化射流钻进机理及现场应用

Mechanisms and Application of Hydraulic Pulsed Cavitating Jet Assisted Drilling

水力脉冲空化射流钻进是将水力脉冲与空化射流耦合的一种新型钻进方式,通过流体脉冲扰动和自振空化效应耦合,使进入钻头的常规连续流动调制成振动脉冲流动,在井底有限井段形成低压区,减小压持效应,避免重复切屑,同时改变井底岩石的受力形态,产生疲劳破坏,降低破岩荷载,提高机械钻速。对水力脉冲空化射流钻进在塔河油田超深井进行了应用分析,发现与常规钻进相同地层岩性的机械钻速对比,在砂岩及粉砂质泥岩段有很大提高,但在水敏性泥岩段不明显。总体上在塔河油田水力脉冲空化射流钻进具有较大的推广应用价值。

Hydraulic pulsed cavitating jet assisted drilling was a new drill method that matched the hydraulic pulse and cavitating jet.When drilling fluid flowed through the tool,the continuum flow was modulated to vibratory impulse flow through the coupling of flow pulse perturbation and autooscillation cavitation effect,then a low pressure area was formed at the bottom to reduce fthe effect to avoid cutting again.Simultaneously the strained condition of rock was changed which caused rock endurance failure to reduce crack-load and increase penetration rate in under-balance drilling.According to the analysis of the application in ultra-deep well in Tahe Oilfield,the penetration rate is raised observably compared with common drilling in sandstone and siltite,but not obvious in water sensitivity mudstone.In general,it has good application prospects in Tahe Oilfield.