The present invention relates to a downhole patch setting tool for expanding a patch over a distance of more than 10 metres in a well, the downhole patch setting tool having a top and comprising a tool body having a bore, an outer face, a first end and a second end, the second end being arranged closer to the top than the first end, a first bladder assembly arranged at the first end on the outer face and a second bladder assembly arranged at the second end on the outer face, the bore at least extending from the first bladder assembly to the second bladder assembly, an expandable metal patch circumferenting the tool body, the first bladder assembly and the second bladder assembly creating an annular space therebetween, the expandable metal patch having an inner diameter in an unexpanded condition, the tool body having a first opening opposite the first bladder assembly and a second opening opposite the second bladder assembly, providing fluid communication between the bore and the first bladder assembly and the second bladder assembly in order to allow pressurised fluid into the bladder assemblies to expand the bladder assemblies, wherein the tool body has a third opening arranged between the first bladder assembly and the second bladder assembly, and a valve arranged in the third opening for controlling passage of the pressurised fluid from the bore to the annular space. The present invention also relates to a downhole completion system and to a patch setting method.