采用膨胀套管技术优化复杂深井超深井下部井身结构

Optimization of bottom casing program of complicated deep and ultra-deep wells based on expandable casing techniques

为了探索采用膨胀套管技术优化复杂地质条件下的深井、超深井井身结构的可行性,采用理论分析与计算机有限元模拟研究手段,对在φ244.5 mm套管以下采用φ193 mm和φ139.7 mm膨胀套管的新的井身结构方案进行了分析论证,并对膨胀后的套管强度进行了有限元模拟计算。结果表明,相对于传统设计,新的井身结构可以在φ244.5 mm套管以下多增加2层套管,并且膨胀套管的膨胀幅度可以根据需要进行优选,而且110 ksi和80 ksi钢级的膨胀套管膨胀后的强度是能够满足要求的。认为应用膨胀套管技术优化深井、超深井下部井身结构是解决复杂地质条件下深井、超深井钻井问题的一个值得探索的好方法。

To probe into the feasibility of optimizing the casing program of deep andultra-deep wells under complicated geological conditions using expandable casing techniques, theoretical analysis and finite element simulation are applied to analyze and demonstrate the new casing program plan of using the O 193 mm and O 139.7 mm expandable casing. What＇s more, the finite element simulating calculation of the casing strength after expansion is conducted. Results show that two layers of casing can be added below the 0244.5 mm casing by using the new casing program. The extent of expansion can be selected according to requirements. The strength of the 110ksi and 80ksi steel grade casing after expansion is qualified. It is considered that the expandable casing techniques deserve exploration to solve the problems of deep and ultra-deep wells drilling under complicated geological conditions.