深部煤层具有高地应力、中高温度、特低渗透、强压缩性、强非均质性等特点，目前尚未形成成熟的开发技术体系，复杂的地质特征为钻井与完井工程带来了新的技术难题与挑战，亟需开展针对深部煤层储层地质特征的钻完井理论与技术攻关，助力油气增储上产，保障国家能源战略安全。

基于鄂尔多斯盆地东缘神府区块深部煤层气开发先导性试验，研发了一套高效钻完井关键技术。

(1)针对深部煤层井壁稳定性差、钻速低、钻井周期长，通过优化二开井身结构、优选钻井液体系与一趟钻技术，并结合井眼轨迹精细化控制，实现了深部煤层一体化高效钻进，助力“新优快”井台建设落地；(2)针对深部煤层地质特征复杂、采用常规压裂规模产量低，形成了以“定向射孔+前置酸液降破压+段内多簇密切割+高排量大规模+一体化变黏滑溜水+暂堵转向+多粒径组合支撑剂”为核心的复合极限规模化压裂技术体系；(3)基于“一区一策+全局寻优”的工作理念，设计立体井网工厂化钻完井作业模式，最优水平井距为350 m时，“拉链式”压裂模式效果最佳；(4)“深部煤层气+致密气”协同开采，获得了更高的工业气流，多气合采是提升鄂尔多斯盆地东缘非常规天然气开发效益的重要措施。研究结果有望为鄂尔多斯盆地深部煤层高效钻完井技术提供理论指导与实践经验。

Deep coal seams exhibit high in situ stress, moderate to high temperatures, ultra-low permeability, high compressibility, and significant heterogeneity, leading to the absence of mature technical systems for their exploitation presently. The complex geological characteristics of deep coal seams pose new technical challenges to their drilling and completion engineering, rendering it urgent to tackle theoretical and technical challenges in drilling and completion tailored to the geological characteristics of deep coal seam reservoirs. The purpose is to achieve the reserve growth and production addition of hydrocarbons in order to guarantee China's strategic energy security.

Based on the pilot tests for deep coalbed methane (CBM) production in the Shenfu block along the eastern margin of the Ordos Basin, a set of critical techniques have been developed for efficient drilling and completion.

(1) Given the low wellbore stability, low drilling rates, and prolonged drilling cycles of deep coal seams, integrated and efficient drilling of deep coal seams has been achieved by optimization using a second-spud-in casing program, the optimal drilling fluid system, and one-trip drilling technique, combined with fine-scale control of borehole trajectories. Such technology can boost the construction of innovative, optimized, and efficient well platforms; (2) To address the challenge posed by the complex geological characteristics and low hydrocarbon production through conventional fracturing of deep coal seams, a composite extremely large-scale fracturing technology system has been developed, which centers on directional perforation, pre-acid to reduce fracturing pressure, multi-cluster closely spaced fracturing within intervals, large-scale fracturing at high injection rates of fracturing fluids, integrated viscosity-variable slickwater, temporary plugging and diverting, and proppants with multiple grain sizes; (3) Following the work philosophy of one strategy for one block and global optimization, a factory drilling and completion operation mode for a stereoscopic well pattern has been designed, with the zipper fracturing mode manifesting the best performance at an optimal horizontal well spacing of 350 m; (4) The high industrial gas flow from the commingled production of deep CBM and tight gas proves that multi-gas commingled production serves as a significant measure to enhance the production efficiency of unconventional natural gas along the eastern margin of the Ordos Basin. It is expected that the findings of this study will provide theoretical guidance and practical experience for the efficient drilling and completion techniques for deep coal seams in the Ordos Basin.