在渤海花岗岩中钻中曲率大斜度井的实践

PRACTICES OF DRILLING THE WELLS WITH MIDDLE CURVATURE AND LARGE INCLINATION IN BOHAI GRANITE FORMATION

渤海石油公司为了开发花岗岩油气藏,在海上钻成了一口高难度中曲率大斜度定向井,该井在2617m造斜,最大狗腿度21.2°/30m,最大井斜75°,贯穿花岗岩地层73m,水平位移271.21m,完全达到了地质设计要求。该井使用了MWD测量技术、顶部驱动钻井技术、同向双弯马达在硬地层造斜技术以及花岗岩地层中的井眼轨迹控制技术、MMH泥浆技术等5项关键技术,使得整个作业过程安全、顺利。文中总结了该井在钻具结构、机械钻速、钻头的使用以及泥浆工艺等方面的实践经验,为今后在花岗岩地层中钻大斜度和水平井,积累了宝贵的经验。

A very difficult directional well with middle curvature and large inclination,the biggest doglegging of 21.2°/30 m,hole deviation of 75° and horizontal section of 271.21 m,deflecting at 2 617 m and running through granite formation of 73 m,was drilled by Bohai Company,CNOPC five techniques such as MWD survey,top drive drilling,deflecting in hard formation by use of accordant direction and double bend motor,controlling well track in granite formation and MMH mud have been used to make the whole operation safe and smooth. The practical experience concerning the drilling tool texture, penetration rate,bit service, technology etc. are summarized to accumulate abundant experiences for drilling the horizontal wells with large inclination in granite formation.