超高压辅助钻井高压喷嘴侧倾角模拟研究  

STUDY ON HIGH PRESSURE SPRAY NOZZLE'S ROLL ANGLE UNDER THE ENVIRONMENT OF ULTRA-HIGH PRESSURE SUBMERGED JETTING

作　　者：董学成[1] 王春[2] 卓智川 廖刚 

机构地区：[1]油气藏地质及开发工程国家重点实验室.西南石油大学 [2]CACT作业者集团 [3]川庆钻探公司井下作业公司 [4]川庆钻探工程公司钻采工程技术研究院

出　　处：《钻采工艺》2011年第5期16-18,95,共4页Drilling & Production Technology

基　　金：国家自然科学基金项目:西南油气深井物理法随钻防漏堵漏(编号:90610013)

摘　　要：利用超高压射流在井底圆周上切割出一圆形切槽,改变井底待破碎岩石应力状态,辅助提高机械破岩效率,为此,通过建立井底流场计算域,运用数值模拟的手段,在K-ε两方程数学模型基础上计算封闭的N-S方程,对简化的三牙轮钻头超高压淹没射流在高压喷嘴不同侧倾角情况下的井底流场进行模拟。模拟发现随着超高压喷嘴侧倾角的减小,井底平面上高速流体的漫流速度增加,过流面积增加,等速核的长度增大,直射点的最大静压力增大。分析认为超高压喷嘴侧倾角的减小有助于井底岩屑的及时清洗;在喷射速度、喷距、喷嘴直径一定的情况下,针对不同门限压力值的岩石,存在一个最大的超高压喷嘴侧倾角角度,侧倾角角度小于等于8°时,超高压射流对于大部分岩石都适用。This paper showed a new method,using high pressure water jet to cut out a circular cutting in the bottom hole rock. This method can change the bottom hole rock's stress state and enhance the rock fragmentation efficiency. Through numerical modelling,some laws were found that with the decrease of roll angle the crossflow velocity of high-speed flow on the bottom hole increased,the flow area increased,the length of potential core increased,point-blank point's static pressure increased. A conclusion was got that the decrease of roll angle was conducive to the migration and clearing of the drill cuttings from the bottomhole. When jet velocity,spraying distance and nozzle diameter were definite,for rock with different threshold pressure,there was a biggest roll angle. When the roll angle was less than 8°,the ultra-high pressure water jet could break most of rock which have different hardness.

关 键 词：超高压淹没射流 破岩效率 侧倾角 井底流场 数值模拟 

分 类 号：TE21[石油与天然气工程—油气井工程]