Technical Research Of Using Geothermal Water For Heat Tracing In Gathering System Of Oil Field

The main aim of this paper is to make good use of the abundant geothermal resource in HuaBei oil field. Exploiting geothermal energy from the abandoned wells and taking the place of some fuel can save energy and reduce consumption. Firstly, the geothermal resource utilization status and the available resource of HuaBei oil field were investigated, and a feasible study for geothermal energy utilization was conducted. The water flow model in geothermal well was established, and the geothermal water outlet temperature and wellbore heat loss were obtained. The flow model of geothermal water pipes was established at the same time and the effect of thermal insulation on heat loss of pipeline was studied. Appropriate insulation material and thickness were choosed to calculate the hot water temperature reaching combined station. Then the whole planning for geothermal resource utilization was maked based on the principle of energy conservation and environmental protection, and the geothermal water was allocated reasonably according to the requirements of oil field.According to the water quality conditions, the two-stage heat exchange system using geothermal water indirectly was designed. Appropriate heat exchange equipment was choosed to improve thermal efficiency and working life as far as possible. The range of geothermal water temperature was extended by using absorption hot-pump and part of hot water for heating was heated. According to the structure and technology feature of gathering flow of oil field, four-stage utilization scheme of hot water was proposed in order to improve hot water efficiency. This paper focused on the analyses of oil heat transmission, dehydrating of crude oil, oil storage tank heat preservation and heat tracing of oil pipeline. Appropriate heat exchange equipment was choosed and cascading use of hot water was maked.When calculate the heat tracing pipeline, we apply the energy equilibrium analysis model of crude oil tracing pipeline system. The effect was compared with different methods of heat tracing using numerical simulation of heat tracing pipeline system. According to the heat tracing methods of gathering flow of oil, pipeline network form and the numbers of pipeline, thermal and hydraulic calculation methods of heat tracing system were studied and established by using fluid mechanics and engineering thermodynamics theory. Then the temperature, flow rate and other parameters of hot water could be determined, the heat loss and head loss of pipelines were calculated, the efficiency of gathering system and the utilization ratio of system and so on were calculated. Then the energy flow curves of geothermal utilization system were drawed and the efficiency of system was analysed using three links method. At last, the economic benifit of the system was analysed after reconstruction.