Abstract: In order to solve the challenges posed to drilling fluid such as wellbore stabilization,hole cleaning,lubrication,rheological property control and reservoir protection in 3rd spud section of Well Xia 103-1HF,which is the first unconventional horizontal well in Linpan Region of Shengli Oilfield,aluminum-amine drilling fluid was investigated.The formula of aluminum-amine drilling fluid was optimized through experiments on selecting and compounding amine,aluminum polymer,and physical plugging agents,filtrate reducers,lubricants and rheological regulators.Laboratory evaluation test showed that the aluminum-amine drilling fluid had strong inhibition,strong plugging,good lubrication,good rheological property,good temperature tolerance,with core permeability recovery rate reaching over 90%.Field application showed that the rheological property of aluminum-amine drilling fluid was stable,with the ratio of yield value to plastic viscosity at around 0.5,API filter loss of less than 2.4 milliters,HTHP filter loss of less than 8.0 milliters,and the mud cake adhesion coefficient of less than 0.1.The excellent performance of the drilling fluid enables the smooth and safe drilling of the well,with all the challenges in this well addressed.The 3rd spud section hole is regular,with an average hole diameter enlargement ratio of 2.0%.The successful application of aluminum-amine drilling fluid in Well Xia 103-1HF showed that this drilling fluid could be popularized and applied in other unconventional hig angle wells or horizontal wells in Linpan Region.