低效气田套管经济可靠性选择

Reliable and economical selection for casing pipe in low-potential gas field

王建东 林凯 赵克枫 王新虎 王建军

WANG Jian-dong LIN Kai ZHAO Ke-feng WANG Xin-hu WANG Jian-jun

中国石油天然气集团公司管材研究所, 陕西西安 710065

Institute of Tubular Goods of China Petroleum and Gas Group Company, Xian 710065, Shaanxi, China

低效气田开发中套管的经济可靠性选择是降低开发成本的有效措施之一。通过API长圆螺纹套管的适用性评价试验明确了影响螺纹密封性能的主要因素;结合低效气田苏里格的实际工况和主流井身结构,依据套管历史实物试验数据统计结果,采用可靠性分析方法确定了套管柱设计的安全系数,校核了载荷变异性对套管柱可靠性的影响,成功设计了2套管柱方案:?139.7mm×7.72/9.17 mm N80/J55 LC+CATTS101特殊螺纹脂复合套管柱和?139.7 mm×9.17 mm N80 LC+CATTS101特殊螺纹脂套管柱;套管螺纹参数按紧密距、螺距控制,接箍不圆度控制在0.7%以下,用最佳~最大扭矩上扣,过盈圈数不少于1.70圈;采用CATTS101螺纹脂上扣,涂抹均匀、适量;依据影响套管适用性的各种因素制定了套管订货补充技术条件和现场操作规范。在油田现场推广应用160多口井,运行良好,取得显著的经济效益。

Reliable and economical selection of casing pipe in development of low-potential gas field is one of efficient measurements to reduce development cost.The main influence factors are specified by application evaluation test of API long round thread casing pipe.With actual working conditions and mainstream well structure of low-potential Sulige gas field,according to statistical results of experimental data for casing historical goods,the safety coefficient of string casing design is determined by reliability analysis methods,reliable effect of load variability on casing pipe is checked,and two string plans is designed successfully.They are ?139.7mm×7.72/9.17 mm N80/J55 LC+CATTS101 special thread compound casing string and ?139.7 mm×9.17 mm N80 LC+CATTS101 special thread casing string.Casing thread parameter controls collar out-of-roundness under 0.7% by standoff and pitch.Optimum and maximum torque is used for threading and interference coils are not less than 1.70 coils.CATTS101 thread compounds are used for threading,which should have uniform and appropriate painting.According to various factors influencing casing pipe suitability,additional technical specification for casing order and field operation specification are established.As a result,more than 160 wells,taking the said measurements,have good performance and make remarkable economic benefit.

10.3969/j.issn.1000-7393.2007.05.027