Energy Consumption Analysis And Calculation Models For Oil Well And Corresponding Study On Optimization Design Of Well Lift

The traditional optimization design of artificial lift is based on the optimal design of the Parameters for machine,rod and pump that can meet the specific output.Its essence is to optimize the efficiency of the lifting device(equipment)that can provide a certain amount of energy,with the purpose of not only meeting the lifting requirements but also saving energy.However,the utilization efficiency of the energy for the oil well itself,that is,the oil well efficiency,is always ignored in those kinds of design methods,oil well efficiency is the efficiency that the oil well using the natural energy provided by the formation.In the case of insufficient formation energy,when the wellhead pressure is constant,the energy that drives a certain amount of fluid to flow from the bottom of the well to the wellhead is certain,while lifted in different positions,the energy consumption for the flow process is different,and the energy required to be provided is also different,that is to say,the degree of natural energy utilizationfor lifting at different positions is different.How to make full use of the formation energy,improve oil well efficiency,reduce energy consumption and reduce energy input is worth studying.Even if the efficiency of lifting equipment itself is not taken into account,from the perspective of multi-phase flow in wellbore and inflow performance of oil well,when the formation energy is insufficient,different depth of the pump means different energy needed to be provided,and the utilization efficiency of natural energy is also different.Based on the above idea,this Paper firstly studies calculation methods of lifting energy required for different rate and different depths of vertical wells,and sensitivity analysis of related influencing factors are conducted.On this basis,the characterization method of oil well efficiency is provided,and the calculation model of oil well efficiency is established.With the increasing demand for energy and continuous improvement of exploration and development technology,the proportion of directional wells,horizontal wells,multilateral wells in the drilling wells is increasing,and there are different deviated sections in these wells.In this Paper,an experimental device is also established to simulate two-phase flow in inclined shaft with different dip angles.Through physical simulation experiments,the influence of angle of inclined shaft on multi-phase flow in wellbore,especially the transition boundary of two-phase flow Pattern,is studied,which provides fundamental researches for the establishment of calculation models of energy consumption,lift pressure difference and oil well efficiency corresponding to wells with inclined sections.This Paper also studied the oil well efficiency and system efficiency of deep wells and ultra deep wells lifted by the tandem lift system in the development process of deep oil and gas reservoirs and offshore oil fields.The efficiency of the oil well itself for alternative lifting is not only related to the position of each lifting point in the wellbore,but also the matching relationship of the energy of each lifting point.In view of the lack of considering the efficiency of the well itself in the existing artificial lift optimization design,this Paper studies and analyzes the utilization efficiency of the natural energy of the well itself on the basis of inflow performance of the well and multiphase flow in the wellbore,combined with the thinking of the node analysis method of the oil and gas well system.The efficiency of the oil well itself is characterized and calculated,the optimization design methods of rod pump considering the oil well efficiency and the efficiency of lifting equipment are further studied.For replacement lifting in deep wells,the calculation method of wellbore energy consumption and oil well efficiency under different lifting position combination,lifting distance and matching relationship of lifting pressure difference required for each position are studied,and the corresponding lifting optimization design method parameter is developed.