I say, and with God's success: If a large sheep dies in the well, all the water of the well should be drawn out if possible, or an estimate of what is in it should be made by two men who have knowledge of the water if one cannot draw out all of it due to the abundance of water and its generation. This is different from if a small lamb of the sheep dies in the well; in that case, it is obligatory to draw out (40) buckets from the well and recommended to draw out (60). See: Hashiyat al-Tahthawi, pp. 36-37, and God knows best.