中国低阶煤煤层气资源量约为10.3×10¹² m³，其中二连盆地群占总资源量的四分之一，具有大规模工业开发潜力。二连盆地吉尔嘎朗图区块煤储层具有低阶煤（镜质体反射率为0.35%，）、低温（26.6 ℃）、低杨氏模量（1 500~2 000 MPa）、低压力系数（1.02~1.03）、低含气量（1.8 m³/t）、超低延伸应力（7 MPa）、巨厚煤层（垂直厚度40~128 m）“六低一厚”的特点。前期勘探评价22口井，由于对地质认识不深入、工艺体系不成熟、技术方案不匹配等因素，各井在压裂投产后均未取得理想产气效果。该研究在深化研究区地质条件认识基础上，明确开发存在的关键问题，认识到低含气量需要体积压裂获取工业气量，温度低需要攻关低温破胶技术防止储层伤害，巨厚煤层需要优选优质主力层段集中改造，低压力系数需要降低泥浆漏失与压裂液滤失，塑性强需要克服支撑剂嵌入对导流能力的影响。在厘清压裂改造难点后，针对性攻关形成了基于地质工程一体化压裂理念的低煤阶水平井聚能分段体积压裂技术。修正机械比能模型，计算煤岩破碎指数进行煤岩可压性评价，进而优选出地质工程双“甜点”集中压裂改造。升级低温可溶桥塞+射孔联作压裂工艺，光套管泵注提供高排量压裂施工空间。匹配射孔参数，射孔长度2 m，孔密16孔/m，相位角60°螺旋射孔。优化压裂规模与强度，设计压裂液量1 500 m³/段，加砂用量180 m³/段，排量18 m³/min。研发低温、低质量浓度、低伤害胍胶压裂液体系，采用粒径分别为0.106~0.212 mm、0.212~0.425 mm、0.425~0.850 mm的组合加砂方式。在研究区JP1井现场成功应用，压后稳定日产气量突破4 000 m³，成为中国低阶煤套管压裂水平井产量最高单井，有力助推了中国低阶煤煤层气效益开发进程。

Low-rank coalbed methane (CBM) resources in China are approximately 10.3 × 10¹² m³, with the Erlian Basin group accounting for one-quarter of the total, indicating significant potential for large-scale industrial development. The coal reservoirs in the Jiergalangtu block of the Erlian Basin are characterized by six “lows” and one “thick”: low coal rank (vitrinite reflectance R_O of 0.35%), low temperature (26.6 ℃), low Young’s modulus (1 500 to 2 000 MPa), low pressure coefficient (1.02 to 1.03), low gas content (1.8 m³/t), ultra-low tensile stress (7 MPa), and an extremely thick coal seam (vertical thickness of 40 to 128 m). In the early exploration and evaluation stage, 22 wells were fractured and put into production. However, none achieved ideal gas production output due to insufficient geological understanding, immature engineering techniques, and mismatched technical designs. Based on an enhanced understanding of the geological conditions, this study identified the key challenges to development. The low gas content necessitated volume fracturing to achieve industrial-scale gas production. The low temperature required breakthroughs in low-temperature gel-breaking technology to prevent reservoir damage. The extremely thick coal seam necessitated careful selection of high-quality main layers for concentrated stimulation. The low pressure coefficient required strategies to reduce mud loss and fracturing fluid filtration. The strong plasticity required measures to mitigate the impact of proppant embedment on fracture conductivity. After clarifying and addressing these challenges, the research established an integrated geological-engineering fracturing strategy for low-rank coal horizontal wells using energy-focused staged volume fracturing technology. The mechanical specific energy model was modified to calculate the coal rock breakage index, thereby enabling the evaluation of coal fracability and identification of geological-engineering dual “sweet spots” for focused stimulation. A combined fracturing technique of low-temperature soluble bridge plug and perforation was upgraded, and the unperforated casing pumping was used to facilitate adequate operational space for high-displacement fracturing. Perforation parameters were optimized as follows: perforation length of 2 m, hole density of 16 holes/m, and a 60° phased spiral perforation. The fracturing scale and intensity were optimized, with a designed fluid volume of 1 500 m³ per stage, sand addition volume of 180 m³ per stage, and a displacement rate of 18 m³/min. A low-temperature, low-concentration, and low-damage guar gum fracturing fluid system was developed, and a combination of sand addition schemes was used with particle sizes of 0.106~0.212 mm, 0.212~0.425 mm, and 0.425~0.850 mm. This integrated technology was successfully applied to well JP1 in the research area. After fracturing, the well achieved a stable gas production rate exceeding 4 000 m³/day, making it the highest-producing single well among low-rank CBM horizontal wells with cased-hole fracturing in China. This successful application effectively promotes the efficient development of low-rank CBM in China.