Establishment And Application Of Energy Efficiency Benchmarking System For Offshore Crude Oil Gathering And Transportation Systems

Offshore crude oil gathering and transportation system is an important part of offshore oil field development process.Its energy consumption accounts for about 35%of the system energy consumption.Because of the special load and environmental conditions,its oil and gas processing technology and equipment are significantly different from those of onshore oil field gathering and transportation.With the increasing demand for energy utilization of energy-consuming enterprises during the 13th Five-Year Plan period,how to achieve energy conservation,low carbon environmental protection and sustainable development has gradually become a concern of the whole society.Therefore,it is of far-reaching significance to control the rising energy consumption of offshore crude oil gathering and transportation system and reduce the energy consumption of offshore oil field development process to realize the efficient operation and scientific management of offshore oil field development system.Firstly,through the analysis of four typical gathering and transporting processes of offshore oilfields,the main energy consumption equipments and links of the system are concluded as follows:heating furnace,pump,three-phase separator,electric dehydrator and submarine pipeline,and the energy efficiency analysis and energy-saving monitoring model of the above energy consumption links are established.Secondly,the overall energy consumption of the system is analyzed by using grey box theory and grey correlation analysis model;a comprehensive weight calculation method is validated and used;an energy efficiency prediction model is established and validated by introducing comprehensive impact factors of indicators.Thirdly,according to the above theoretical analysis,a set of energy efficiency benchmarking analysis software for offshore crude oil gathering and transportation system is developed by using MATLAB.Finally,taking an offshore oilfield gathering and transportation system as an example,the index system and the benchmarking software are validated.Through analysis,the main energy consumption links of the oilfield are:gas heating furnace,crude oil outflow pump,crude oil lifting pump,electric dehydrator,three-phase separator and submarine pipeline.The energy consumption of energy-consuming equipment in the oilfield is calculated and analyzed by using energy efficiency benchmarking analysis software.The main energy consumption problems are summarized as follows:high exhaust gas temperature of heating furnace,low pump efficiency,high heat loss on the surface of separator,high load rate of electric dehydrator,excessive temperature drop of submarine pipeline,etc.The energy efficiency prediction model is used to predict the energy efficiency of heating furnace,three-phase separator and electric dehydrator.The results show that the comprehensive energy efficiency will be increased to about 88.5%,91.84%and 78.2%respectively,which exceed the initial benchmark value.This also shows that the energy efficiency benchmarking system established in this paper has strong feasibility,can find the energy efficiency gap reasonably,and has made a beneficial attempt for benchmarking management idea to be applied to energy efficiency monitoring and energy saving potential tapping of offshore crude oil gathering and transportation system.