针对致密砂岩地层的复合垢问题，以酸、白油、复合乳化剂、助剂制备一种酸包油型微乳解堵剂。采用透射电子显微镜（transmission electron microscopy, TEM）、动态光散射（dynamic light scattering, DLS）表征了微乳解堵剂内部结构及形态，并对微乳解堵剂进行了热稳定性与无机垢堵溶蚀、有机堵溶解、储层伤害性等性能评价。采用X射线光电子能谱（X-ray photoelectron spectroscopy, XPS）、扫描电子显微镜（scanning electron microscopy, SEM）以及能量色散仪谱（energy dispersive spectroscopy, EDS）对解堵机理进行了研究。解堵剂在溶液中呈球状分散，平均粒径6 nm，90 ℃稳定48 h以上，对不同位置形成的复合垢溶蚀率分别达到87.61%、77.41%，微乳解堵剂能将油润湿（120°）反转为水润湿（35°），相比于酸解堵液，微乳解堵剂能更快更有效解除复杂垢堵。岩芯驱替实验，微乳解堵剂能将岩芯渗透率恢复率提高到80%以上。研究表明，微乳解堵剂具有热稳定性好、溶垢能力高、能够有效去除有机无机复杂垢等优点，可有效解除井筒、近井地带堵塞物，疏通井筒及地层渗流通道，提高油气产能。

To address the issue of composite scale in dense sandstone formations, an oil-in-acid microemulsion unblocking agent comprising acid, white oil, composite emulsifiers, and additives was developed. The internal structure and morphology of the microemulsion unblocking agent were characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Its performance was assessed in terms of thermal stability, dissolution efficiency for inorganic and organic scale plugs, and impact on reservoir permeability. The mechanism of unblocking was investigated using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The microemulsion unblocking agent exhibited a spherical dispersion in solution with an average particle size of 6 nm, and maintained stability at 90 ℃ for over 48 h. The dissolution rates for scale formed at different locations were 87.61% and 77.41%. The microemulsion unblocking agent the ability to transition from oil wettingto water wetting, and proved more efficient and faster in resolving complex scale plugging compared to traditional acid solvents. The microemulsion unblocking agent enhanced core permeability recovery rates to over 80%. Results highlight the advantages of the microemulsion unblocking agent, including excellent thermal stability, high scale dissolution capacity, and effective removal of both organic and inorganic composite scales, They can efficiently eliminate obstructions in the wellbore and near-wellbore regions, thereby clearing the wellbore and enhancing the flow paths in the formation and increasing oil and gas production capacity.