南堡3号构造中深层大斜度井钻井技术

Drilling technology for deep long displacement and highly deviated well in Nanpu No.3 Structure

南堡3号构造油藏埋藏深度3 800~4 500 m,受地面条件和地质靶点的制约,主力储层主要采用长位移大斜度井开发。针对该地区储层埋藏深、地层温度高、斜井段长、井壁失稳严重、地层可钻性差、机械钻速低、钻井周期长等技术难题,开展了井身结构及井眼轨迹设计、防磨减扭技术措施、提高泥页岩井壁稳定性的抗高温钻井液性能优化、高效PDC钻头的优化设计及提速工具的现场试验等方面的综合研究。现场应用取得了明显效果,机械钻速提高了39.86%,平均单井钻井周期缩短了38.5%;井径扩大率控制在7%以内,井眼质量得到了明显的改善,实现了该地区水平位移在3 500 m范围内长位移大斜度井安全快速钻井的目标,为加快南堡3号构造中深层沙河街组油藏勘探开发步伐提供了保障。

The formation depth of Nanpu No.3 Structure is 3 800-4 500 meters. Controlled by the field conditions and geological targets, the deep long displacement and highly deviated well was used for reservoir development. Considering the high formation depth and temperature, long inclined section, poor wellbore stability, low drilling rate and long drilling period, the targeted comprehensive technology researches were carried out, including well structure design, well trajectory design, anti-abrasion and torque reduction technology, shale wall stability improvement, anti-high temperature drilling fluid, efficient PDC bit and speed field tools. The successful results of field application show that the mechanical drilling speed increases by 39.86%, and the average single well drilling cycle is shortened by 38.5%; the well diameter expansion rate is controlled within 7%, and the borehole quality is improved obviously. This realizes the safe and rapid drilling with long deviation controlled by 3 500 meters and high slope, which provides technical support for the development of deep Shahejie Formation in Nanpu No.3 Structure.