China Coal Research Institute
Xi’an Research Institute of China Coal Technology & Engineering Group Corp
College of Geology and Environment, Xi’an University of Science and Technology

黄陇煤田开采面临巨厚洛河组砂岩顶板水害的威胁。针对彬长矿区高家堡煤矿洛河组砂岩骨架的微观孔隙特征展开实验室研究，综合运用XRD衍射，铸体薄片、扫描电镜研究了砂岩骨架颗粒的孔隙类型，采用覆压孔渗探究其不同压力下的孔隙率和渗透率变化特征，联合高压压汞和核磁共振手段表征了砂岩岩心的孔喉半径大小，结合X射线三维CT扫描对砂岩内部大于9 μm的孔隙进行精细定量化表征，结果表明：① 中粒砂岩骨架颗粒大，孔隙类型主要以剩余粒间孔为主，少量粒间溶孔，而细粒砂岩骨架颗粒小，颗粒间多由黏土矿物填充，为次生溶蚀粒间孔，少量粒内溶孔，孔隙发育较小；②中粒砂岩中的大孔孔喉半径介于0.61～4.94 μm，累积分布频率达到48%，而细粒砂岩中的大孔孔喉半径介于0.188～0.683 μm，累积分布频率达到47%，说明中粒砂岩的孔喉半径较大，更有利于地下水存储和运移；③ CT显示中粒砂岩平均面孔隙率为7.081%，细粒砂岩平均面孔隙率为2.032%，中粒砂岩内高度发育的大孔(等效孔隙直径>180 μm)和微孔贡献了较高的面孔隙率，结合较大的孔喉半径，宏观表现较高的渗透性，两者的微观孔隙特征与现场对应含水层的富水层评价相一致。研究成果可为洛河组砂岩顶板水害防治提供基础参考。

The mining of Huanglong Coalfield faces a serious threat from roof sandstone water disaster of the extremely thick Luohe Formation. A laboratory study on the microscopic pore characteristics of the sandstone of the Luohe Formation in the Gaojiapu Coal Mine, Binchang Mining Area were carried out using various methods. XRD diffraction, casting thin sections, and scanning electron microscopy were combined to study the pore types of the sandstone particles. Overburden porosimeter was used to illustrate the variation characteristics of porosity and permeability under different confining pressures. High-pressure mercury injection and nuclear magnetic resonance techniques were used to characterize the pore-throat radius of the sandstone core, and X-ray three-dimensional CT scanning was used to quantitatively characterize sandstone pores larger than 9 μm. The results show that, ①the sandstone particles of medium-grained sandstone are larger, and the pore types are mainly residual intergranular pores with a small amount of intergranular dissolved pores, while the particles of fine-grained sandstone are smaller, and the intergranular pores are mostly filled with clay minerals, secondary dissolution intergranular pores, and a smaller degree of pore development.; ②The pore throat radius of large pores in medium-grained sandstone ranges from 0.61 to 4.94 μm, with a cumulative distribution frequency of 48%, while in fine-grained sandstone, the pore-throat radius ranges from 0.188 to 0.683 um, with a cumulative distribution frequency of 47%, indicating that medium-grained sandstone has larger pore-throat radius, which are more conducive to groundwater storage and migration.; ③CT scanning shows that the average surface porosity of medium-grained sandstone is 7.081%, and that of fine grained sandstone is 2.032%. The highly developed macropores (equivalent pore diameter > 180 μm) and micropores contribute to a higher surface porosity. Combined with a larger pore throat radius, the medium-grained sandstone presents a higher permeability. The microscopic pore characteristics of the two types of sandstone are consistent with the on-site evaluation result of the water yield propertyof the corresponding aquifer. The research findings can provide a basic reference for the prevention and control of water disasters from the sandstone roof of the Luohe Formation.

国家自然科学基金资助项目（52004326）；陕西省2023年自然科学基础研究计划资助项目（2023-JC-QN-0459）

冯龙飞，王双明，王　海，等. 彬长矿区典型顶板水害矿井洛河组砂岩微观孔隙特征研究[J]. 煤炭科学技术，2023，51（8）：208−218

FENG Longfei，WANG Shuangming，WANG Hai，et al. Micro pore characteristics of Luohe aquifer sandstone in Binchang Mining Area typical roof water hazard mines[J]. Coal Science and Technology，2023，51（8）：208−218