Reaserch Of The Characteristics Of Gas And Water Distribution And The Regulations Of Water Production In The Tahe AT11Block Gas Condensate Reservoir With Bottom Water

Gas condensate reservoirs, such as Banqiao, Kekeya, Dazhangtuo, Yaha, etc, have been already developed in our country. In recent years, lots of gas condensate reservoirs have also been found in the eastern and western areas. With the growing production of condensate oil and gas in our country, the development of gas condensate reservoirs increasingly attracts attention of domestic and foreign scholars. Gas condensate reservoir is a special kind reservoir, which is developed difficultly owing to the complicate variation of fluid’s phase state, especially for the development of gas condensate reservoirs with bottom water. When the pressure drops to below the dew point pressure in the process of gas condensate reservoir with bottom water development, interphase mass transfer and phase change would occur in the heavy hydrocarbon of gas phase, condensate oil starts to condense from around the wellbore to the deep reservoir, and it will not immediately flow unless the condensate oil saturation reaches the critical saturation. When the pressure of reservoir continues to decline and spreads to gas-water contact, bottom water coning will happen at the direction of pressure drawdown. In this case, multi phase flow will happen in the process of fluid flowing from boundary to the bottom of the well and there may be single-phase gas flow, gas and water two-phase flow, gas, oil and water three-phase flow, making it complex for the development of condensate gas reservoir. Gas condensate reservoir with bottom water is very special and complex. First, it can extract both gas and condensate oil with the higher economic value. On the other hand, it has its particularity. It has broad applied prospects to develop the research on the water breakthrough characteristics and laws for improving the development effect and economic benefit.The thesis takes AT11gas condensate reservoir with bottom water controlled by Northwest Petroleum Bureau as research object. This paper mainly focuses on the research about water breakthrough characteristics and gas—water distribution laws of gas condensate reservoir with bottom water. During the development of this kind of reservoir, if the gas well produces water, it will lead to serious problems. Gas wells will stop producing due to water flooding. At the same time, water blocking will happen during the production, which can decrease the gas wells’production and retard the development progress and economic benefit. The thesis starts from the gas wells with water problems to judge the sources of water production, studies the regulation of the gas production and the distribution characteristics of gas and water, puts forward the managed projects with the combination of gas wells, water resistance wells and water wells, it has important significance to improve the development effect of condensate gas reservoir with bottom water.The contents and results of this thesis mainly include the following aspects:1. Summarized production characteristics of AT11gas condensate reservoir, based on the original distribution characteristics of gas water interface, calculated the condensate water content in gas wells using Mcketta-Wehe chart, then judged the sources of water comprehensivly with dynamic analysis method.2. Analyzed the influencing parameters of water breakthrough time in the process of production, including interlayers, speed of gas extraction, height of water avoidance and reservoir thickness, especially studied the interlayer distribution characteristics, from the position of the interlayer, scale of the interlayer, penetration of the interlayer.3. Designed different models of reservoirs, including with interlayesr or with high permeability zones and only with interlayers, using numerical simulation technology to study the mechanism of water production in different reservoirs.4. Established the geologic model of AT11gas reservoir, analysed different water coning patterns of gas wells after phase behavior and history matching, and summed up the characteristics of bottom water intrusion, AT11block’s gas-water distribution and the distribution of residual gas are shown clearly, then analysed the formation factors of residual gas from the micro and macro sides, micro factors contain fingering, snap, and leaving on the pore blind side and corner; macro factors mainly contain the bottom water coning, interlayer cover and bottom water plane channeling.5. Analysed the principle of arranging gas wells, water resistance wells and water wells, and then put forward4corresponding design projects, finally optimizing the best scheme using numerical simulation.