Phase Behavior Of Gas Condensate Wells And Nodal Analysis Calculation

Gas condensate reservoir is a kind of special and complex gas reservoir with high economic value. With enlargement of oil and natural gas exploration & development scale, gas condensate reservoir is becoming more and more important all over the world. When the reservoir pressure reduces below the dew-point pressure during the production process, the retrograde behavior will occur, thus liquid will separate from vapor phase. This special feature causes huge difficulty for gas condensate development, which is called the world class research topic. Production of gas condensate scientifically and effectively is one of urgent-solved problems.This thesis makes a variety of literature review. Choosing widely-used calculation formulas of condensate fluids physical parameter from many experiences equations provides basic data for the following calculation; Based on rigid theory of thermodynamics with PR-EOS and SRK-EOS, a gas-liquid two phases equilibrium model is established and gets the solution by Newton-Raphson iteration method; Based on phase equilibrium, the inflow performance model of the three-region pattern is established with considering phase behavior change, liquid condensate and non-Darcy flow of vapor phase. Pseudo-pressure and every boundary are determinated by numerical integration and theory of steady respectively. Using steady Darcy flow, steady non-Darcy flow and experience equation, we evaluate well productivity. According to mass conservation, momentum conservation and c energy conservation and different temperature and pressure, two-phase flow models of Hagedorn-Brown and Beggs-Brill with phase change are established, the latter is also applied to horizontal pipes. The single flow adopts Cullender-Smith model.The basic of the thesis is vapor-liquid phase equilibrium, the research object of which is the overall production system of condensate well. The practical program is made using Visual Basic 6.0 according to theory of nodal system analysis, including phase equilibrium module, IPR module, borehole pipe flow module and ground pipe flow from reservoir to well bottom, to well head, to separator. Using actual data of condensate well of Daqing oilfield Hailaer area, we study sensitive parameters such as tubing diameter, gas nipple diameter, wellhead pressure and well bottom pressure on effect of deliverability. Therefore, we can determinate reasonable production drawdown, match point flow rate and limited production condition in order to reduce utmost loss of condensate oil in reservoir and guide highly effective and economic production of gas condensate reservoir, which is of extreme significance.