含水凝析气相态特征及非平衡压降过程产液特征  

Phase behaviors of condensate gas with vaporous water and liquid production characteristics in a non-equilibrium pressure drop process

作　　者：王长权[1,2] 汤勇[1] 杜志敏[1] 陈亮[3] 孙扬[1] 潘毅[1] 石立红[4] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500 [2]长江大学石油工程学院,湖北荆州434023 [3]中国石油新疆油田公司,新疆克拉玛依834000 [4]西南石油大学化学化工学院,四川成都610500

出　　处：《石油学报》2013年第4期740-746,共7页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.50604011)资助

摘　　要：气态水的存在对凝析气藏相态特征的影响不容忽视,常规的相态测试过程无法模拟含水凝析气田开发过程中近井带的非平衡压降过程的实际产液特征。利用PVT筒开展了含气态水凝析油气体系相态特征实验,研究了气态水对凝析气相态特征的影响,并通过缩短凝析气体系定容衰竭过程的平衡时间,模拟含水凝析气田开发过程近井带的非平衡压降衰竭过程,对比分析了非平衡压降过程含水凝析气体系中凝析油、水的抽提蒸发效应。结果表明,气态水的存在引起了凝析油气体系中重质含量的增加,导致露点压力升高,反凝析提前,最大反凝析压力提高,反凝析液量增加。含水凝析油气体系在非平衡压降衰竭过程中,由于气液相体系未达平衡,导致液相滞后析出并随气相运动一起被采出,造成凝析油采出程度和产水量提高,且非平衡压降速度越大,凝析油采出程度越高。因此,凝析气田近井带的非平衡压降有利于凝析油的开采并缓解液锁的发生。The effect of vaporous water on phase behaviors of gas condensate reservoirs should not be ignored, and through conven- tional phase-equilibrium experiments it is unable to simulate the real liquid production features during the non-equilibrium pressure drop process of a nea^wellbore formation in development of aqueous gas-condensate reservoirs. Therefore, a series of experiments was performed to investigate phase characteristics of the aqueous gas-condensate system using the PVT cell, in which the effect of vaporous water on phase behaviors was examined, the depletion process of non-equilibrium pressure drop within near-wellbore for- mations in development of aqueous gas-condensate reservoirs was simulated by shortening equilibrium time of the constant volume de- pletion （CVD）, and analytical comparisons were made on extraction and evaporation effects of condensate and water in an aqueous gas-condensate system during the non-equilibrium pressure drop process. The results show that the content of heavy hydrocarbon components in a gas condensate reservoir will increase due to the presence of gaseous water, which results in a rise in dewpoint pres- sure, advance of retrograde condensation and an increase in both the maximum pressure and the liquid volume of retrograde conden- sation. During the non-equilibrium pressure drop depletion of an aqueous gas-condensate reservoir, the liquid of retrograde condensa- tion is recovered along with gas due to the non-equilibrium of the gas-liquid system, resulting in an increase in both the condensate recovery ratio and the water production, moreover, the faster the speed of non-equilibrium pressure drop, the higher the ratio of con- densate recovery. Consequently the non-equilibrium pressure drop within near-wellbore formations of a gas condensate field is propi- tious to both the condensate development and the liauid blocking alleviation.

关 键 词：气态水 凝析气 高温高压 相态 非平衡压降 产液特征 

分 类 号：TE372[石油与天然气工程—油气田开发工程]