Rich Gaseous Condensate Water Condensate System States And Its Application

The common oil-gas mixtures phase behavior study ignores the influence of formation water. With the mumble of condensate gas reservoirs in abnormally high temperature and pressure increasing, the related study and the development of such condensate gas reservoirs indicated that the study and its application of condensate gas reservoirs with rich gaseous condensate water in abnormally high temperature and pressure have great influence on the developments of condensate gas reservoirs. Under formation condition of abnormally high temperature and pressure, bottom water, edge water and active porous water coexist with condensate gas in vapor. In order to estimate the mutual solubility between formation water and condensate gas and the influence of formation gaseous condensate water on phase behavior of oil-gas mixtures and the developments of gas reservoirs, this paper carries out a series of experiments, then establishes a gas-liquid-liquid 3-phase equilibrium model which suits for oil-gas mixtures with rich gaseous condensate water, and use experiments data to simulate phase behavior for gas-liquid-liquid 3-phase equilibrium with rich gaseous condensate water.Through systematical study, the following results are achieved in this paper.1. A phase behavior test scheme is designed for condensate gas-oil mixtures with rich gaseous condensate water in abnormally high temperature and pressure. The scheme is used to analyze gas content in formation water and water content in condensate gas, estimate condensate liquid saturation, condensate liquid content, condensate liquid and gas recovery, and water output from gas in Constant Composition Expansion (CCE) and Constant Volume Depression (CVD) processes.2.Common phase behavior tests without water and phase behavior tests with rich gaseous condensate water are carried out on the formation fluid from the same gas reservoir. The comparisons between two experiments results prove high solubility of formation water in condensate gas under formation condition of abnormally high temperature and pressure. So, water content in condensate gas can't be ignored for phase behavior analysis of condensate gas-oil mixture in developing scheme organization. The solubility of formation gaseous condensate water greatly influences the compositions of well fluids, dew point pressure, oil-gas compressibility, the amount of condensate liquid, condensate liquid recovery and so on.3.This paper establishes a set of material balance model and thermodynamic balance model for gas-liquid-liquid 3-phase equilibrium gaseous condensate water, which suit to condensate gas reservoirs with rich gaseous condensate water in abnormally high temperature and pressure. Considering the polarity of water, fugacity and fugacity coefficient by PR EOS are used to deal with oil phase and condensate gas phase, while activity coefficient by the theory of regularity solution is used to deal with water phase. Huron-Vidal a-parameter mixing rule connects PR EOS and the theory of regularity solution. Gas-liquid-liquid 3-phase equilibrium model is solvedby Newton-Ruffison gaseous condensate water on algorithmAAn phase envelope algorithm is put forward for gas-liquid-liquid 3-phase equilibrium of condensate gas reservoirs considering gaseous condensate water. The algorithm can trace the influence of water content on dew point line and bubble point line of the mixtures, trace 3-phase phase boundaries of oil-gas-water mixtures, and can forecast 3-phase points.5.Gas-liquid-liquid 3-phase equilibrium model is used to simulate saturated vapor content and liquid water content in separator, condensate liquid saturation, condensate liquid content and cumulative recovery under formation condition. Simulated results well match the results of PVT test. The new model is used to simulate phase envelope for formation fluid from Zhongyuan Qiaokou condensate gas reservoir with rich gaseous condensate water. 6. This paper can apply the experiment results of oil-gas mixtures phase behavior with rich gaseous condensate water and the results from phase b...