The well inclination angle reaches or approaches 90°, and the well body is drilled along the horizontal direction to a certain length. As shown in the accompanying drawing, the wellbore extends horizontally into the oil formation for a considerable length. Sometimes for some special needs, the well inclination angle can exceed 90°, "upward". Generally speaking, horizontal wells are suitable for thin oil and gas layers or fractured oil and gas reservoirs, with the purpose of increasing the exposed area of ??oil and gas layers.