准噶尔盆地南缘冲断带--呼探1井超深井钻井方案优化

STUDY ON ULTRA DEEP WELL DRILLING TECHNOLOGY IN THE THRUST BELT OF THE SOUTHERN MARGIN OF JUNGGAR BASIN--WELL HU TAN 1

呼探1井是中石油股份公司2019年在在准噶尔盆地南缘山前部署的一口重点风险探井,勘探意义十分重大。该井设计井深7 280 m,存在井身质量控制困难、钻井提速难度大、喷漏风险并存、钻井液和水泥浆性能维护难度大、固井质量难以保证等钻井技术难点。为此,根据该井所钻遇地层的特点,充分考虑预探井风险,在保证钻井安全的前提下,兼顾井身质量、效率、经济等因素,剖析邻井资料,与地质紧密结合,充分考虑钻井存在的风险,确定了五开井身结构,采用主动防斜技术、PDC钻头及辅助工具试验的强化、钻具组合采用"螺杆+MWD+PDC钻头"复合钻井技术,提高钻井速度;优化完善钻井液体系,采用油基钻井液体系以有效应对钻井过程中可能存在的各种复杂情况;针对固井难点,提出四开随钻扩眼,以提高窄环空间隙的顶替效率,五开采用抗高温的水泥浆体系以确保固井质量,为今后超深井设计提供理论参考。

Well Hutan 1 is a key risk exploration well deployed by PetroChina in the southern margin of Junggar Basin in 2019.It is of great significance for exploration.The design depth of the well is 7280 meters.There are many difficulties in drilling technology,such as the difficulty of wellbore quality control,the difficulty of increas⁃ing drilling speed,the coexistence of blowout risk,the difficulty of maintaining drilling fluid and cement slurry performance,and the difficulty of guaranteeing cementing quality.Therefore,according to the characteristics of the strata drilled by the well,taking full account of the risk of the pre-exploration well,taking into account the factors of wellbore quality,efficiency and economy,the data of adjacent wells are analyzed,closely combined with geology,fully considering the risks of drilling,the structure of the Five-opening wellbore is determined,and the active deviation prevention technology,PDC bit and auxiliary tool test are adopted to strengthen and drill tools are adopted.The combination uses the"screw+MWD+PDC bit"composite drilling technology to improve drilling speed;optimizes and improves drilling fluid system,uses oil-based drilling fluid system to effectively deal with various complex situations that may exist in the drilling process;in view of the difficulties in cementing,proposes four hole while drilling enlargement to improve the displacement efficiency of narrow annular space gap,and uses high temperature resistant cement slurry system to ensure cementing quality.