中文摘要：

定北区块地层承压能力普遍较低,漏失层位多,水平井技套固井封固段超过4 000 m,漏失是制约定北区块固井质量的关键问题。结合地层压力数据,兼顾一、二级固井防漏需要,确定了分级箍安放位置优化方法;下套管前,先期堵漏提高了地层承压能力;设计先导稀水泥浆,保证足够的紊流接触时间,有效地冲刷了井壁虚泥饼;双速替浆方法使得替浆排量产生的动摩阻不能超过薄弱地层承压能力与环空浆柱压力之差,既满足了固井防漏需要又提高了顶替效率。该工艺技术应用于定北区块LP15H等水平井的技术套管固井,有效解决了普遍固井漏失问题,提高了固井质量。

英文摘要：

There are generally low formation loading capacity,more thief zones,and more than 4 000 m sealing interval of intermediate casing cementing for horizontal wells in Dingbei block. Leaking is a key problem to restrict cementing quality in the block. On the basis of formation pressure data,considering antileakage requirements for first and two stages cementing,the stage collar position in casing string was optimized. Before running casing,plugging in advance can increase the formation loading capacity. Thin cement slurring was circulated to ensure enough turbulent contact time and wash effectively uncompacted mud cake.The dual- speed displacing mud method can guarantee the running friction less than the difference between formation bearing pressure and fluid column pressure,which can not only meet requirements of antileakage but also increase displacement efficiency. The antileakage cementing technology was successfully applied in intermediate casing cementing for horizontal wells such as LP15 H well in Dingbei block and can effectively control cement loss and improve the cementing quality.