Study On The Method Of Reservable Reserves For Girard Edge Water Condensate Gas Reservoirs

In recent years, with the exploration and development of pertroleum, we have found a lot of edge and bottom water gas condensate reservoir. Due to high development value of condensate gas reservoir, it gets more and more people’s attention. However, it is still lack of proper gas condensate reservoir recoverable reserves computational method of the country. To solve the situation of a large gap between the evaluations of recoverable reserves of the Jilake condensate reservoir with bottom edge water in different time, which in the Tarim gas field, and the results are not ideal, it is more urgent need to work out a complete system of gas condensate reservoir recoverable reserves calibration method.Based on a large number of international and domestic literature of gas condensate reservoir, taking the modern reservoir engineering technology theory, methods of gas reservoir engineering, and well testing analysis, combine the static data and dynamic characteristics of Jilake gas condensate reservoir, several aspects of condensate reservoir have been researched and the corresponding results mainly as follows:(1) Analysising the applicable conditions of each abandoned condition methods, six condensate gas reservoir conditions calibration methods are summed up, which apply to Jilake bottom edge condensate gas reservoir:four kinds of abandonment pressure calibration method and two kinds of waste production calibration method. Finally, the burial depth conversion method and comprehensive analysis (economy-productivity equation-bottomhole pressure method) are optimized.(2) Respectively, both from dry gas and condensate oil, the literatures of gas condensate reservoir recovery factor calibration methods both in domestic and foreign are researched. Four kinds of methods are summarized:analogy method, empirical formula method, analytical method, and Hagoot material balance method, another, analysis the advantages of these methods deeply. Ultimately, preferred Hagoot material balance method, which more in line with gas condensate reservoirs’ unique thermodynamic properties, and calibrated the recovery factors of Jilake gas condensate reservoirs, dry gas and condensate oil respectively.(3) On the basis of recoverable gas reserves standard calibration method, the current conventional domestic and international gas condensate reservoir recoverable reserves of calibration methods are summarized, including:volumetric method, material balance method, the pressure recovery curve method, improved attenuation curve method, water drive characteristic curve method.Then, the problems of gas recoverable reserves methods are improved. Considering the phenomenon of retrograde condensate, material balance equation of edge and bottom water with oil ring gas condensate reservoir is derived theoretically. While combining gas condensate reservoir material balance equation and linear quadratic productivity equation, material balance combined with the productivity equation method is proved. Explore the linear relationship between the wellhead pressure and production of condensate gas, dynamic diminishing law are improved, it can directly obtain the recoverable oil reserves and recoverable reserves of gas condensate. The prediction models of recoverable reserves are solved by trial and error method. Introduction of condensate gas formation volume factor, virtual curve method are improved, the results show that the improved abandonment pressure higher, the recoverable reserves smaller, and it is more suitable for gas condensate reservoirs.Using actual production data of Jilake condensate gas reservoirs for the above method make examples, the applicability of each method in Jilake gas condensate reservoirs are evaluated. Then, the advantages and probelems of methods are analyzed deely. Ultimately, prefer recoverable reserves calibration methods are selected in order, which apply to Jilake gas condensate reservoir. This paper make a progress in the recoverable reserves calibration methods on the edge and bottom water with oil ring gas condensate reservoir which depletion developed. This research gives guidance to the same type of gas condensate reservoir of calculation recoverable reserves, and has some practical value.