Debottlenecking of Oil Processing Train Capacity

摘要

There was an urgent requirement for a low-cost fast-track solution to increase the oil processing capacity in one of the ADNOC Offshore facilities in order to facilitate the scheduled maintainence of the Oil Trains as well as to handle additional production before a new train is commissioned. Capacity of each of the four Oil Trains is primarily limited by the vibration problem of the 1st vessel (Inlet Sphere) in the train, due to which field tests could not be performed to establish Oil Train maximum throughput. It was concluded through detailed studies, including Computation Fluid Dynamic Analysis, that there is no techno-economically feasible solution to overcome the vibration problem of the Inlet Spheres. However, the problem could be circumvented if the extra flow is routed to the downstream facilities by bypassing the Inlet Sphere completely. The objective of this in-house study is to find a low-cost solution to overcome the limitation of the Inlet Spheres and other bottlenecks in the trains. Based on the debottlenecking study outcome, it was proposed to use the stand-by Emergency Sphere-while retaining its original design functionality of handling emergency liquid relief-and its associated Crude Transfer Pump to transfer the additional flow (above the Inlet Sphere allowable capacity) directly to the Inlet Sphere downstream system. Similarly, course of actions were also identified for other bottlenecks. Based on the debottlenecking study recommendations, it was agreed to carry out the modification in two of the four Oil Trains considering the Crude Transfer Pump capacity limitation as well as to keep the cost to minimum by maximizing the usage of the existing assets. Subsequent to the modifications, field tests were conducted and test result showed that the oil-handling capacity of each Oil Train could be increased by 17%. No change in the operating conditions of the existing facilities were required and all the specifications of export crude oil were also met. Based on the test results, other improvements were also suggested. Accordingly, it was concluded to embark on executing the proposed modifications for all the Oil Trains. The debottlenecking scheme, which is implemented at a cost of ~1 Million USD, is able to generate a revenue of ~2 Million USD per day. Hence, the scheme when extended to the all the four trains would generate a revenue of ~8 Million USD per day. Execution cost for this modification for all the four trains is estimated to be less than 15 Million USD, whereas a new train of similar capacity would cost more than 200 Million USD.