Abstract: Horizontal wells are more and more valuable beginning from adopted to oil and gas development. In fact, horizontal wells are used as producers as more as possible in offshore fields. The case was studied when horizontal and vertical wells were simultaneously deployed as producers and injectors respectively. It assumed that a central vertical well was surrounded by several horizontal wells. The producibility equations of horizontal wells in areal well spacing were presented by the equivalent flowing resistance method. It was efficient to predict that how much output should be designed for the development units of horizontal wells.