| According to subsequent development needs, two production facilities(include platforms and subsea pipelines) to be established on the south side of Panyu 4-2WHP platform and Panyu 5-1 WHP platform for meeting the demand of the late development. Considering the property of oil is heavy in new development zone, the new platforms must be required to meet some special standards. Such as the safe transportation of subsea pipe, the transport capacity, the oil concentration of the wastewater and so on.The main function of the platform is to separate oil, gas and water. In addition, the platform is the core of the development and production system in offshore oil field. The paper mainly discussed the treatment system of the crude oil and the oily sewage and the transportation system of subsea pipe. At first, the reliable API and ASME standard was used as the basis of theoretical calculation for the crude oil treatment system and the oily sewage treatment system. Secondly, according to the HYSYS software simulating the systems, we can acknowledge the handling capacity and the operating paramete rs. Reference to the operation parameters of Panyu 4-2WHP platform, we fully consider the operating parameters of Panyu 4-2DPPA platform and the physical parameters of crude oil, the pressure of output, the inlet pressure of FPSO, the inlet pressure of subsea tee, the oil temperature, the flow in subsea pipeline and so on. Study and design the subsea pipeline transport process of crude oil in Panyu 4-2DPPA platform; Considering the high content of heavy oil and wax in the new platform, we used the Pipesim software to simulate and research the minimum throughput of the subsea pipeline, at the same time, we explore the before-running pre-heat and stop running pre-heat of the subsea pipeline, the influence to the subsea pipeline’s hydraulic power and heating power when the platform shuts down, the allowed stop running time, displacement of subsea pipeline and the sensitivity of the main operating parameters.The results of this study show that the rate of water content of crude oil will be kept below 15% after the secondary treatment under the normal operating condition, and the crude oil concentration of oily sewage can be reduce to 20 mg/L and below through by water conservancy whirl and air flotation at the same time. These both can meet the requirement of the original design. The water content of the crude oil can be reduce to 0.5% and below for the crude oil with water after two stage separation to be pressurized and heated to 98℃, and to be dehydrated by the electric dehydrator. The whole flow rate of the crude oil must exceed 510 m3/d (15% water content) to assure the crude oil mixture to flow into the FPSO under the condition of the minimum throughput of 200 m3/d, including Panyu 4-2WHP and Panyu 4-2DPPA platform. The minimum temperature of the subsea pipeline shutdown is 40℃, and the allowable shutdown time is 2 hours. The flow rate is more sensitive than the temperature and the viscosity of the crude oil to the pipeline pressure. All those not only provide theoretical reference to reservoir adjustment, secondary development design and operation safety assureance in Panyu oil field, but also be took as an example for the design of the gathering and transportation planning of other similar offshore oil and gas fields. |
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