高温高压深井射孔段套管应力理论计算与分析  

Analysis of Stresses on Casings in Perforated Intervals of HTHP Deep Wells

作　　者：岳艳芳[1] 仝少凯[2] 窦益华[3] 

机构地区：[1]华北油田公司采油工程研究院 [2]川庆钻探工程有限公司长庆井下技术作业公司 [3]西安石油大学机械工程学院

出　　处：《石油机械》2015年第4期48-53,共6页China Petroleum Machinery

摘　　要：在高温高压深井套管射孔完井作业过程中,井下套管处在极为复杂恶劣的环境中,特别是封隔器以下套管受射孔冲击力的影响,受力状态瞬间发生改变,出现瞬间失稳、脉动甚至弯曲折断现象。为此,综合考虑内外压、油层出砂及套管自重等因素,运用断裂力学理论和有限元法分析射孔段套管的应力,对比分析其强度安全性。分析结果表明,相同工况及出砂量下,外径139.7 mm、壁厚9.17 mm和10.54 mm射孔套管应力理论解比有限元解大;大量出砂使射孔段套管发生弯曲,射孔改变了套管的力学性质;孔眼附近有应力集中现象,造成射孔处套管抗挤强度降低;孔眼周围的应力沿螺旋线布孔方向相对较小。研究内容可为优选射孔工艺、泵压、排量、套管规格与钢级等参数提供必要的参考依据。During perforation and completion of HTHP deep wells, casings may experience extremely complicated and unfavorable environments. It is worth mentioning that casings below the packer may be subject to impacts of perforation and experience instantaneous instability, pulsing, curving or breaking due to changes in instantaneous forces. Under such circumstances, internal and external pressures, sand production from pay zones, weights of casings and other factors shall be considered jointly. At the same time, fracturing mechanics theories and finite element methods shall be used to analyze stresses on perforated casings and to determine their structural safety. Analysis results show that theoretical solutions related to perforated casing with OD of 139.7 mm and wall thick-nesses of 9. 17 mm and 10. 54 mm are higher than solutions obtained by using finite element methods under the same working conditions and sand production volumes. Massive sand production may induce bending of perforated casings, and at the same time, perforation may change dynamic properties of these casings. Concentration of stres- ses around the perforation holes may lead to reduction in collapsing strength of casing over there. Stresses around perforation holes are relatively small along the direction of helical hole distribution. The researches can provide nec-essary references for selection of optimal perforation technology, pumping pressures, discharging capacities, casing specifications, steel grades and other parameters.

关 键 词：深井 套管 射孔 应力 出砂 断裂力学 有限元分析 

分 类 号：TE925[石油与天然气工程—石油机械设备]