| Nowadays, the formational pressure of Yaha gas condensating reservoir is below the dew point pressure, and the retrograde condensate phenomenon is serious, which has great influence on gas well or reservoir, making the productivity of gas well declines substantially.In order to draw the reasonable producing system, the methods of nodal system analysis and material balance principle is applied to have dynamic analysis and optimal design, aiming at the production system of gas condensate wells,which makes the efficient and rational development of gas condensate reservoir become reality. So, the main accomplished work of this article is as follows:1. Incorporating the PR state equation and providing the fluid two phase equilibrium model solution method has provided the phase equilibrium theoretical foundation for the Yaha block gas-condensate well production performance analysis.2. Based on the condensation gas reservoir steady seepage theory, the condensate oil in the Yaha block is regarded as the Darcy seepage because of its low delivery and flow rate in the reservoir.However, the condensate gas own the character that the kinematic viscosity is low and the flow rate is fast in the stratum,for which its flow can be regarded as the Non-Darcy seepage; The oil-gas two-phase inflow dynamic mathematical model is established in the stratum seepage section and the relevant solution method is provided.3. The Yaha block 87 testing datas of the 15 wells are evaluated and analysed by using the common computation model which includes Gray model, the Hagedorn&Brown model, the Duns&Ros model, the Mukherjee&Bril model. Because of the flowing pressure intersection chart and the smallest relative performance coefficient(RPF), the Gray model is selected and it fits for the wellbore pressure calculation of this block.4. On the basis of the gas-fluid two-phase production equation and the gas condensate well vertical pipe flow computation, the establishment of the nodal system analysing and computing model is appropriate for the gas condensate well in the Yaha block; By using the nodal system analysis procedure,the flow-in and flow-out dynamic curve plate for the gas condensate well is plotted, and some factor, including wellhead pressure,tubing diameter and gas nipple diameter,which will affect the condensate gas production, is analysed sensitively.5. With these methods of the prevention to the liquid loading and sand entry at the bottom of a well and the appearance of the retrograde condensate pressure border, the rational drawdown for the Yaha gas condensate well is established integratively,so the reasonable production of the gas condensate well is determined.6. On the basis of the material balance principle, the rational production and some key production datas altered regularly,such as rational production and the gas well production during the steady and deceasing production period at the present production, can make comparison and analysis. The recovery at the rational production during the steady production and the end of the decreasing period is higher than the recovery at the present production.In view of the Yaha block, a set of studying gas condensate well dynamic production system optimization and designing theory and method is determine by using the above theory. The procedure of the gas condensate well production performance system analysis programed by the use of the VB, analyse the effect to the gas condensate well production as a result of the the drop out of the condensate oil and some parameter including tubing diameter and wellhead pressure is analysed sensitively.The rational production parameters are optimized,and the gas condensate well performance can be predicted.the optimal reasonable production parameter, as well as has forecast the gas-condensate well dynamic change. This article can provide technological method for the prediction of the condensate gas production and the establishment of the rational production condition as well as the optimizing and designing of the tube pillars. |
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