Off Shore Production System Optimization

Offshore operations are usually associated with limited space, limited production system capacity and high cost for additional facilities. The efficiency of operations and the optimum utilization of available equipment are of prime importance. Efficient use of offshore production system necessitates the study of such systems as a whole. The span from reservoir to storage tanks, passing through production wells, manifold, pipelines, and facilities, is to be covered by investigation to identify possible bottlenecks and areas of improvement that would affect overall system performance. Ashrafi field with its satellite; Ashrafi-SW Field is a complex system where production is transferred from the SW platform through one 6" pipeline-in-addition to two 4½" coil tubing lines. In the main platform, Ashrafi Field production is mixed with SW production and then transferred to the shore, 17 kilometers away, through a 16" main pipeline. The processing of crude is performed in the onshore facilities. A multi phase flow simulation software has been used to provide a rigorous and comprehensive engineering picture of the Ashrafi system. The analysis starts with the reservoir and well design using nodal analysis. Effect of changes in fluid properties, gas-oil ratio and water cut on pressure traverse are studied. Results of possible water and gas shut-off actions are predicted through application of the software. The whole wells and pipelines network is then modeled and the outcome of possible improving actions is analyzed to help define the economical factors associated with the actions. Recommendations for shut-in of some high water cut wells, possible application of artificial lifting and effect of water injection implementation are analyzed. This paper discusses the system components, matching of actual system data and the results of the applied actions are also presented along with recommendations for optimization.