尾管固井回接压裂套管屈曲失效研究

Casing buckling failure analysis in tie?鄄back fracturing under liner cementing conditions

杨同玉 韩峰 马兰荣3

中国石化华北油气分公司，河南 郑州 450006 北京石油化工学院，北京 102617 中国石化石油工程技术研究院，北京 100101）

North China Oil & Gas Company, Zhengzhou 450006, China Beijing Institute of Petrochemical Technology, Beijing 102617, China SINOPEC Research Institute of Petroleum Engineering, Beijing 100101, China)

尾管固井回接压裂技术已成为中石化鄂北致密低渗油气藏储层改造的重要手段，压裂施工中的高压对回接套管的结构安全性提出了很高的要求。针对尾管固井回接压裂施工中套管出现的屈曲变形，运用理论分析和数值模拟方法研究了套管在高压作用下的屈曲失效形式。分析结果表明，?准114.3 mm N80钢级的回接套管在不同施工压力下的屈曲失效形式是不同的。当施工压力超过20 MPa时，套管就会发生正弦屈曲；压力超过50 MPa时，套管将会以螺旋屈曲的形式发生失效。为保障施工安全，提出了预防套管失效的关键措施，优化了回接管柱方案。

The tie?鄄back fracturing under liner cementing conditions is an effective way of stimulating the tight and low?鄄permeability reservoirs in SINOPEC North Ordos Basin. The high pressure in fracturing presents very high demand on the structure safety of casing. Focusing on the deformations of casing in tie?鄄back fracturing under liner cementing conditions, casing failure modes under high pressure condition are researched by theoretical analysis and numerical simulation. The results show that the failure modes are quite different due to the different operating pressure values for N80 casing of ?准4.5". When the operating pressure is more than 20 MPa, the casing deformation has the sine wave form. If the operating pressure is more than 50 MPa, the failure mode will be helical form instead. In order to ensure the engineering safety, measures are suggested to prevent such failure, and tie?鄄back design is optimized.

10.6056/dkyqt201905026