近年来，为解放底板高承压灰岩水上煤炭资源，华北煤田普遍采用地面定向钻技术，对太原组薄层灰岩进行区域性注浆加固改造(习称“底板区域治理”)，以全面封堵灰岩岩溶裂隙并阻断垂向导水通道。该技术中，与浆液扩散范围(半径)密切相关的“水平分支孔”孔间距设计问题，一直备受学界和业界的广泛关注。皖北矿区底板区域注浆工程量大，特别是深部资源开采，将有数十亿元的注浆工程，有必要查清浆液扩散范围真实数据。为此，以皖北矿区恒源煤矿为研究基地，依托Ⅱ63采区底板区域治理工程，设计并实施浆液扩散范围示踪试验，在中间的水平分支孔(Z8-7)投放荧光剂(示踪剂)，在两侧的水平分支孔(Z8-6、Z8-8)以及交叉分支检测孔(Z8JC)取岩屑样鉴别荧光水泥，以获得浆液扩散范围，进而在浆液扩散影响因素分析基础上，构建恒源煤矿底板区域注浆治理浆液扩散范围计算公式。结果表明：① 综合岩屑现场及室内鉴别结果分析，获得恒源煤矿Ⅱ63采区底板区域注浆浆液扩散范围为38.3 ～ 44.0 m，且水泥分布密集区在水平分支孔浆液扩散范围30 m以内，该区域内注浆效果最佳。② 通过现场岩屑快速鉴别与室内岩屑精准鉴别，取得的浆液扩散范围基本一致，证明了荧光示踪浆液扩散范围的有效性。③ 通过对比分析，认为在计算参数、边界约束等符合实际注浆工况条件下，浆液扩散范围理论计算和数值模拟结果，与现场示踪试验实测结果较为接近。④ 利用示踪试验过程中的压水试验及注浆参数、钻遇构造及水文地质响应等数据，考虑重力、构造、地下水径流等因素影响，借助SPSS非线性拟合软件，得到恒源煤矿Ⅱ63采区底板区域注浆浆液扩散范围计算公式。⑤ 基于恒源煤矿受注层实际地质、水文地质条件，利用拟合的浆液扩散范围计算公式得出Ⅱ63采区Z8场地浆液扩散范围为37.8 ～ 42.9 m，与浆液扩散范围示踪试验实测结果相近，计算公式可在类似条件下推广应用。本次煤矿底板区域注浆浆液扩散范围现场示踪工程试验，不仅取得了浆液扩散范围的真实数据，而且阐明了浆液扩散与多种地质、水文地质因素之间的内在联系，揭示了超深、超长定向钻注浆浆液扩散机理，构建了浆液扩散范围计算公式，为类似条件下底板区域治理工程水平分支孔孔间距的合理设计提供了参考依据。

In recent years, to liberate coal resources from high pressure limestone water on the coal seam floor, North China Coalfields have generally adopted surface directional drilling technology to carry out regional grouting reinforcement and transformation (commonly known as “floor regional treatment”) on the thin-layer limestone of the Taiyuan Formation in order to comprehensively seal karst cracks in limestone and block vertical guide water channels. In this technology, the design of the spacing between “horizontal branching holes” closely related to the diffusion range (radius) of the slurry has been widely studied by academia and industry. There is a large amount of grouting work in the bottom plate area of the Anhui North mining area, especially in the mining of deep resources, which will cost billions of yuan. It is necessary to verify the true data of the diffusion range of the grout. Therefore, based on the Hengyuan Coal Mine in the northern Anhui mining area as the research base, relying on the II63 mining area floor area treatment project, the slurry diffusion range tracing test was designed and implemented. The fluorescent agent (tracer) was added to the horizontal branch hole (Z8-7) in the middle, and the rock debris samples were taken from the horizontal branch holes (Z8-6, Z8-8) and cross branch detection holes (Z8JC) on both sides to identify fluorescent cement and obtain the diffusion range of the slurry. Furthermore, based on the analysis of the influencing factors of slurry diffusion, a formula for calculating the diffusion range of slurry in the grouting treatment of the bottom plate area of the Hengyuan Coal Mine was constructed. The results show that: ① Based on the analysis of on-site and indoor identification results of rock debris, the diffusion range of grouting slurry under the coal seam floor area of the Hengyuan Coal Mine II63 mining area was 38.3−44.0 m, and the cement distribution was dense within the diffusion range of horizontal branch hole slurry within 30 meters. The grouting effect was the best in this area. ② Through a rapid identification of on-site rock cuttings and precise identification of indoor rock cuttings, the diffusion range of the slurry obtained was basically consistent, proving the effectiveness of fluorescence tracing of the diffusion range of the slurry. ③ Through comparative analysis, it was believed that under actual grouting conditions such as calculation parameters and boundary constraints, the theoretical calculation and numerical simulation results of the slurry diffusion range were close to the measured results of on-site tracing experiments. ④ Using the data from water pressure tests, grouting parameters, drilling structures, and hydrogeological responses during the tracer test process, taking into account the factors such as gravity, structure, and groundwater runoff, and using SPSS nonlinear fitting software, a formula for calculating the diffusion range of grouting slurry in the bottom plate area of the Hengyuan Coal Mine II63 mining area was obtained. ⑤ Based on the actual geological and hydrogeological conditions of the injection layer in the Hengyuan Coal Mine, using the fitted slurry diffusion range calculation formula, the slurry diffusion range of Z8 site in the II63 mining area was obtained to be 37.8−42.9 m, which was similar to the measured results of the slurry diffusion range tracer test. The calculation formula could be promoted and applied under similar conditions. The on-site tracing engineering test of the diffusion range of grouting slurry in the coal mine floor area not only obtained real data on the diffusion range of slurry, but also clarified the inherent relationship between slurry diffusion and various geological and hydrogeological factors. The diffusion mechanism of grouting slurry for ultra deep and ultra long directional drilling was revealed, and a formula for calculating the diffusion range of slurry was constructed, providing a reference basis for the reasonable design of horizontal branch hole spacing in bottom plate area treatment projects under similar conditions.