Hydraulic Modeling of an Off-Shore Crude Oil Emulsion Pumping System

One of the most important facilities of the PEMEX Exploration and Production off-shore transport system has been hydraulically analyzed to determine its current transport capabilities and assess the effect of a possible change of the transported crude oil properties. This facility transports crude oil emulsions from diverse production platforms to an on-land facility that is located 25 miles away from the platform. The current system operates with crude oils in the range of 19° API; however, an increase in the production of heavy oil has been forecasted for the next few years. Thus, the existing pumping equipment and pipeline system need to be evaluated to confirm their satisfactory operation with the expected new mixtures of approximately 16° API. The existing system is a complex, interconnected platform network where different crude oils are mixed and pumped into various pipelines. A water-in-oil emulsion is presented in the system and its composition changes with the different streams that are being mixed in the system. In addition, water cuts and API values vary based on the field that is being produced. A dramatic change of the crude oil quality and API is expected in the next few years. Therefore, the existing booster system will require upgrades and modifications to handle the new operating conditions while the crude oil production is increasing. Currently, the pumping system transports a 350 cP crude oil from an off-shore platform to an on-land receiving terminal through two 36-inch pressurized pipelines. The system includes ten centrifugal pumps; however, an upgrade of the facility will demand the operation of only six pumps (1-6) for the light crude oil. Therefore, it was required to determine if the existing centrifugal pumping equipment, driver, and pipeline system will have the capacity to handle the new conditions while fulfilling the flow rate requirements.