Abstract: The Xiwang 1-B oilfield is a multi-layer wide transitional zone oilfield which is located in South China Sea waters. The simultaneous exploitation in pure oil areas and transitional zones enhanced the control area of wells and the sweep efficiency of the whole oilfield. The best perforation percentage of the wells which are located in the oil layers with bottom water or in transitional zones is about 30%-40%, but the blocking action of sandwich layers and caliches to bottom water must be fully considered. The oil wells that are located in the pure oil areas with distance less than 200 m from edge water must properly avoid being perforated. Reasonable proration is important during well production. It can obtain good production effects to utilize the center casing string with packers inter layers, which controls each measures production, not only combined production but also single zone production. It becomes simple to exploit oil measures and easy to get well information by the individual layer sand control method.