李 智,胥 云,王振铎,陈 作,张光伟

(1.西安石油大学机械工程学院,西安710065;2.中国石油勘探开发研究院廊坊分院,河北廊坊 065007)

水力喷砂压裂工具喷嘴磨损分析

李 智1,胥 云2,王振铎2,陈 作2,张光伟1

(1.西安石油大学机械工程学院,西安710065;2.中国石油勘探开发研究院廊坊分院,河北廊坊 065007)

分析了水力喷砂压裂工具喷嘴磨损的机理。水力喷砂射流对喷嘴的磨损主要是喷砂射流中砂粒对喷嘴内壁材料的冲蚀磨损。砂粒对喷嘴内壁面冲蚀磨损作用的形式包括微切削磨损、疲劳磨损、脆性断裂磨损及扩散磨损等。研究表明:喷嘴材料的微观组织结构及物理力学性能、喷嘴内流道结构形状及几何参数、喷嘴内表面粗糙度、喷砂射流中砂粒浓度、砂粒特性(硬度、粒度、形状等)及射流工作参数(射流压力等)对于喷嘴的磨损都有影响。提出了耐磨材料选择,喷嘴内流道结构优化等延长喷嘴寿命的措施。

压裂;水力喷嘴;喷砂射流;磨损

Abstract:Abrasion mechanism on nozzle of hydraulic sandblast fracturing tools was analyzed.In the hydraulic sandblasting process,the nozzle inner wall was mainly worn down by sand erosion.There are several forms of erosion effect as follow:micro-cutting wear,stress fatigue wear,brittle fracture wear,diffusion wear etc.Studies show that wear of nozzle was affected by many factors,such as the microstructure of the nozzle material,its physical properties and mechanical properties,the shape parameters and geometric parameters of the nozzle inner passageway,the inner surface roughness of the nozzle,sand concentration in abrasive water jet,characteristics of sand(rigidity,particle sizes,shape etc.)and jet operating parameter(jet pressure etc.).Some advices which aimed to enhance the nozzle’s lifespan such as choosing anti-friction material and optimizing nozzle passageway shape are proposed.

Key words:fracturing;hydraulic nozzle;abrasive water jet;wear

水力喷砂压裂中的喷砂射流技术是在管柱中加入砂粒再经由喷嘴喷出形成喷砂射流,利用砂粒的冲击力以提高射流切割、破碎岩石的能力。这是近年发展起来的一项低渗油气储层改造技术,具有广阔前景[1]。在此技术中,喷嘴居于关键元件的地位,其执行效果对于整个射流工作效果至关重要。然而由于喷砂射流对喷嘴的作用,致使喷嘴较易磨损破坏,寿命较短,这降低了水力喷砂射流技术在实际生产中的应用效果,影响了进一步推广使用。……