一种大井眼气井钻井和完井程序正广泛应用于卡塔尔海滨North大型气田的开发。与以前的177.8mm井眼设计相比,大井眼的优势在于可以减少井口数量从而降低开发费用,可以提高井口流动压力从而推迟安装压缩机。大井眼设计已用于个别气田,并在很多井上得到应用。迄今已有多口这样的井钻井并完井,而且都是世界上最高产的气井。这也是将大规模气田开发的大井眼设计与装备设计和制造的特色工业发展相结合的第一批海上气井。对详细设计评价、设备性能试验、质量程序等方面进行了广泛的系统性研究,以满足复杂的井眼可靠性设计要求。这些井的特点是锥形管柱设计,即通常所说的“大井眼优化”(OBB)。本文讨论了这些OBB井在设计与施工中的难题,介绍了最初的OBB井设计、North气田预期会遇到的钻井难题、设备的临界规格,以及在过去4年中通过优化所完成的设计修正。 A wellbore gas well drilling and completion program is being widely used for the development of large North Gas fields on the Qatari coast. Compared with the previous 177.8mm borehole design, the advantage of big boreholes is that they can reduce the number of wellheads and thus reduce development costs, which can increase the wellhead flow pressure and delay the installation of compressors. Large borehole designs have been used in individual gas fields and are applied in many wells. To date, many such wells have been drilled and completed, and both are the most productive gas wells in the world. It is also the first of a series of offshore gas wells that combine the development of large-scale wellbore designs with the distinctive industrial design and manufacture of equipment designed and manufactured. Extensive systematic research has been conducted on detailed design evaluation, equipment performance testing, quality procedures, etc. to meet the complicated design requirements of wellbore reliability. These wells are characterized by a conical column design, commonly referred to as the “Great Hole Optimization” (OBB). This article discusses the design and construction challenges for these OBB wells, describes the original design of the OBB well, the expected drilling challenges for the North gas field, critical equipment specifications, and design corrections that have been made through optimization over the past four years .