井口无支撑段连续油管极限拉压载荷分析  

Analysis of ultimate tension and compression load of coiled tubing in unsupported section of wellhead

作　　者：杨明 刘巨保[1] 王田玉 丁宇奇[1] 岳欠杯[1] 杨宝 YANG Ming;LIU Jubao;WANG Tianyu;DING Yuqi;YUE Qianbei;YANG Bao(School of Mechanical Science and Engineering,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;Oil Recovery Plant No.2,Daqing Oilfield Company Limited,Daqing,Heilongjiang 163414,China)

机构地区：[1]东北石油大学机械科学与工程学院,黑龙江大庆163318 [2]大庆油田有限责任公司第二采油厂,黑龙江大庆163414

出　　处：《东北石油大学学报》2023年第1期116-126,I0008,共12页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(11972114);国家自然科学基金项目(51904075);黑龙江省自然科学基金项目(LH2022A003)。

摘　　要：井口无支撑段连续油管内外压差最大且无井筒约束,易发生弯曲甚至折断。根据Lame公式,推导无支撑段连续油管在轴向载荷和内压作用下极限拉压载荷的理论计算公式;根据ASME规范,建立极限拉压载荷的数值模拟方法,与理论计算公式、试验数据进行验证,采用理论公式计算不同钢级和壁厚的无缺陷连续油管在内压作用时的极限拉压载荷曲线,采用数值方法模拟含椭圆度和壁厚减薄缺陷的连续油管在内压作用时的极限拉压载荷曲线。结果表明:随钢级和壁厚的增加,连续油管的极限拉压载荷逐渐增大;随内压增加,连续油管的极限拉伸载荷先增大后减小,具有极值点,极限下压载荷与内压呈抛物线形式降低;在内压较高时,椭圆度和壁厚减薄缺陷大幅降低连续油管的极限拉压载荷。该结果为现场射孔和压裂作业时井口无支撑段连续油管的压力和载荷评价提供依据。The unsupported section of the wellhead coiled tubing has the largest differential pressure and no wellbore constraints,which is easy to bend or even break.According to the Lame formula,the theoretical calculation formula of the ultimate tension and compression load of coiled tubing in unsupported section under the action of axial load and internal pressure was derived.According to ASME code,the numerical simulation method of ultimate tensile and compressive loads was given,and verified with theoretical calculation formulas and experimental data.The ultimate tensile and compressive load curves of fault-free coiled tubing with different steel grades and wall thickness under internal pressure were calculated by theoretical formula.The ultimate tensile and compressive load curves with ellipticity and wall thinning defects under internal pressure were simulated by numerical method.The results show that the ultimate tensile and compressive load of coiled tubing increases with the increase of steel grade and wall thickness.With the increase of internal pressure,the ultimate tensile load of coiled tubing first increases and then decreases,with an extreme point.The ultimate pressure load decreases with the internal pressure in a parabolic form.At higher internal pressures,the ovality and wall thinning defects significantly reduce the ultimate tensile load of coiled tubing.The results provide a basis for pressure and load evaluation of unsupported coiled tubing in wellhead during perforating and fracturing operations.

关 键 词：连续油管 极限载荷 钢级 壁厚 椭圆度 壁厚减薄 无支撑段 井口 

分 类 号：TE355.7[石油与天然气工程—油气田开发工程]