Research On Characteristics Of Inflow And Outflow Performances For ASP Lifting System

Oil-gas wells production system is a continuous flow process, a whole oil-gas wells production systems generally include the flow process of reservoir to wells, the vertical lifting process in tubing and the horizontal pipe flow process on the ground. Oil-gas wells production system can be divided into two parts including inflow and outflow parts by selecting a random node. The changes of pressure and flow rate are continuous in the whole oi-gas wells production system, coordination deliverability and reasonable bottom flowing pressure of oil-gas wells can be determined through the researchs on characteristics of inflow and outflow performances.Node analysis method is a systematic analysis method in petroleum engineering, which mainly used in the design of manufacturing parameter of oil-gas wells and emphasized harmonious relation between inflow deliverability and lifting ability of oil-gas wells and parameter optimization etc. If bottom of rod pumped well is key node, flow process can be devided into inflow and outflow parts in ASP lifting system. On the researchs of flowing characteristics of two parts, flowing characteristics curves of two parts are ploted. The coordinated point of flowing characteristics curves of two parts corresponds coordination deliverability and reasonable bottom flowing pressure of ASP lifting system. Research on characteristics of inflow and outflow performances in ASP lifting system has practical significance of the project and general theory significance for predicting the deliverability and reasonable bottom flowing pressure of ASP lifting system.On the research of dynamic characteristics of inflow performance of ASP lifting system, the basic differential equations of flow of ASP reservoir fluid were established using power-law fluid model and viscoelastic fluid model respectively in the article, the basic differential equations were dispersed and numerically calculated using non-uniform logarithm grid, on the works of above mentioned, the deliverability of ASP lifting system was forecasted using Lagrange interpolation method when bottom flowing pressure was given, and the results of theoretical arithmetic were compared with the measured data, the percentage of error was less than 20%.On the research of dynamic characteristics of outflow performance in ASP lifting system, the pressure gradient of unsteady flow of production fluid of ASP lifting system which can be looked upon as power-law fluid in annulus which is consisted of pitshaft and pumping rod with pumping rod reciprocating axially motion was calculated by the dichotomy method based on solving the motion equation of unsteady flow of produced fluid of ASP lifting system which can be looked upon as power-law fluid in annulus which is consisted of pitshaft and pumping rod with pumping rod reciprocating axially motion using the finite difference method. On the research of above-mentioned, the bottom flowing pressure of outflow performance of ASP lifting system was solved, and the results of theoretical arithmetic were compared with the measured data, the percentage of error was less than 20%.Based on the researchs of characteristics of inflow and outflow performances of ASP lifting system, associating node analysis method, coordinated point of ASP lifting system was determined, namely coordination deliverability and optimum bottom flowing pressure of ASP lifting system,the influences of a variety of factors on the optimum point of ASP lifting system were analysed in the article.