气体钻井对井口四通冲蚀磨损规律研究  

Erosion and Abrasion of Wellhead Spool induced by Gas Drilling

作　　者：邹康[1] 王健功[1] 杨赟达[2] 艾志久[1] 胡坤[1] 孟璋劼 

机构地区：[1]西南石油大学 [2]宝鸡石油机械有限责任公司

出　　处：《石油机械》2015年第1期21-26,共6页China Petroleum Machinery

基　　金：中石油2011年塔里木油田重点项目"工艺安全与钻完井工程基础研究"之子课题"井口装置"(TLMYT-2011-GC-007)

摘　　要：气体钻井中携岩气体冲击四通内壁是导致四通失效的主要原因。基于气固两相流和冲蚀理论,运用CFD软件对四通本体流体域进行数值计算,分别研究了实际钻井工况下钻杆偏心的情形和不同钻井工艺对四通本体的冲蚀规律。研究结果表明,随着偏心距的增大,岩屑的轴向速度逐渐增大,局部冲蚀速率也呈现增大的趋势;由于偏心造成的岩屑粒子轨迹偏转向四通宽流道一侧冲击,容易在局部造成严重的冲蚀缺陷,导致四通承压能力下降;在不同钻井工艺下,冲蚀速率峰值和流体速度峰值都随注气量和岩屑质量流量的增加而基本呈线性递增趋势,而与岩屑粒径成反比关系,四通出口压力对冲蚀速率的影响不大。因此,在实际钻井中应尽量减少钻杆的偏心作业,合理控制注气量、岩屑质量流量,以保证钻井作业的安全进行。Impacts of cuttings carried by gases to internal walls of spool can be seen as major contributors to failure of such spool in gas drilling. With consideration to theories related to gas/liquid flows and erosion, CFD has been deployed for numerical calculation of fluid domain in the spool to determine eccentricity of drill-pipe during field application and impacts of different drilling technologies to erosion of spool. Research results show that larger eccentricities may lead to higher axial velocities of cuttings and consequently higher local erosion rates. Due to ec- centricity problems, cuttings may impact the wider flowing channel in the spool. Such deviated impacts may induce severe local erosion defects and reduce pressure-beating capacities of the spool. Under different drilling technolo- gies, peak erosion rates and peak fluid flowing velocities may increase with the increase of gas volumes and flowing rates of cuttings. Moreover, these peak valves may decrease with the increase in diameters of such cuttings. Impacts of export pressures of the spool displayed minimum impacts to erosion. During drilling operations, cares shall be taken to minimize eccentricity of drill pipes, to control volume of gas injection and flow rates of cuttings to ensure safety of drilling operations.

关 键 词：气体钻井 气-固两相流 冲蚀 四通本体 CFD 数值模拟 

分 类 号：TE249[石油与天然气工程—油气井工程]