Study On Gas Reservoir Engineering In Condensate Gas Reservoir With Water Vaporization

Condensate gas field plays a very important role in the development of gas field in the world.With the development of petroleum and natural gas,it is found that there are more and more high temperature and high pressure condensate gas reservoirs in the world.With the step-down production process of gas reservoirs,the edge and bottom water and the pore water will evaporate,and then the gaseous water will mix with gas in the gas reservoir under the condition of high temperature.The production practice of condensate gas reservoir in high temperature and high pressure,experiments and numerical simulation indicated that the effect of water on the fluid phase state must be considered to avoid calculating errors in condensate gas phase state parameters,the reserves and production performance evaluation.Through systematical study,including theory,experiments and application,the following results are achieved in this paper:(1)Phase behavior experiments were conducted,using formation fluid with saturated gaseous water and without gaseous water from the same condensate gas reservoir.The results indicated that the dissolution of gaseous water would affect the wellhead composition,dew point pressure,deviation factor,natural gas expansion capacity and amount of anti-condensate in a way.(2)The mechanism and laws of condensate water production during depletion were studied,especially the effect of temperature,pressure,CO2 content,heavy hydrocarbon content and rock properties on water content in condensate gas,and the reasons why the increase of water production in condensate gas field were clear and definite.(3)The basic relationship between condensate content and formation pressure,heavy hydrocarbon content and CO2 content during the production process was established with the experimental data.This method was applied to analyze the mechanism of water production and water source with production data.(4)The calculation method of the basic physical properties of saturated gaseous condensate gas and the physical relationship of the near-wellbore area were screened and revised with experimental results.The productivity of gas wells was evaluated with field test data.Then the difference in gas well production capacity considering and without considering the effects of gaseous water was studied which showed that gas well productivity decreased considering gaseous water.(5)The method of estimating the dynamic reserves considering condensate water was established according to the experimental results and literature survey.The data of gas field production were sorted and the reserves of gas field were calculated,and reserves accounting methods were filtered.