丘东凝析气藏注气提高采收率数值模拟研究

发布时间：2018-05-31 04:26

本文选题：反凝析污染 + 开发方式　；参考：《西南石油大学》2015年硕士论文

【摘要】：凝析气藏衰竭式开发时地层压力逐渐降低,当压力低于露点时,就会出现反凝析现象,在凝析油饱和度逐渐增大达到临界流动饱和度以前,凝析油不会流动,造成越来越大的流动阻力,气相渗透率降低,大大影响凝析油的采出程度和气井产能,形成反凝析污染。因此,研究凝析气藏合理开发方式,解除反凝析污染,提高凝析油采出程度,对高效开发凝析气藏具有重要意义,是凝析气藏开发领域重要的发展趋势和方向。丘东凝析气藏属中含凝析油型的低渗气藏,目前地层能量不足、近井地带凝析油堆积,反凝析污染严重,因此研究丘东凝析气藏开发中后期提高采收率技术手段及其可行性,为丘东凝析气藏下一步开发技术政策制订提供基础理论依据。本文通过气藏工程方法对丘东凝析气藏开发现状进行了分析,包括对气藏产能的分析、46口气井分类评价、33口气井初始及目前无阻流量评价、13口气井递减规律分析、西山窑上下气藏压力系统分析、气藏及气井反凝析饱和度推算、气井不稳定试井分析等；在此基础上结合反凝析污染实验及解除凝析油污染实验进行丘东气藏注气可行性分析,并针对6口注气井进行气藏工程研究,确定气井合理日注气量范围：随后通过数值模拟,建立丘东凝析气藏单井吞吐注气、典型井组循环注气、典型井组整体吞吐注气数值模拟模型,设计28种预测方案优化丘东7井注气总量、日注气量、焖井时间、日采气量、注入周期等单井吞吐注气参数,14种预测方案优化典型井组回注比、日采气量等循环注气参数,最后开展典型井组整体吞吐方案预测,研究丘东凝析气藏注气提高采收率的可行性。研究成果表明：针对丘东凝析气藏正处于开发中后期,气井无阻流量下降幅度较大,气藏目前平均无阻流量相比初始下降69.86%,气井平均递减率为0.1639mon-1,气藏反凝析污染严重,目前平均凝析油饱和度为4.8%,但是气井连通性较好。丘东气藏反凝析污染实验岩心渗透率最大降低幅度为28.79%,而注气解除反凝析污染实验凝析油采出程度相比衰竭降压至废弃地层压力增加了9.48%,另外丘东气藏注气井井口压力在8MPa-20MPa范围内均可选取出气井的合理日注气量范围。论证得到丘东凝析气藏注气可行性较高。针对实际丘东气藏丘东7井,最优吞吐参数包括注气总量200×104m3、日注气量12.5×104m3/d、焖井时间10天、日采气量15×104m3/d、吞吐周期1个,在最优参数下可提高凝析油采出程度0.1904%,提高天然气采出程度1.239%。而针对丘东气藏典型井组,最优回注比0.7情况下循环注气产出投入比较低,相比衰竭式开发提高凝析油、天然气采出程度分别为3.8%、11.22%,具有一定的可行性。最后结合单井吞吐注气及循环注气研究成果,针对同一典型井组开展整体吞吐注气可行性研究,相比衰竭式开采,证明净增加天然气和凝析油量较为可观,产出投入比较高,具有较高的可行性。
[Abstract]:In the development of condensate gas reservoir , the formation pressure gradually decreases , and when the pressure is lower than the dew point , the phenomenon of anti - condensation will occur . Before the saturation of condensate gradually increases to the critical flow saturation , the condensate will not flow , resulting in more and more flow resistance and decrease in gas phase permeability . Therefore , it is an important development trend and direction of condensate gas reservoir development .

This paper analyzes the present situation of gas reservoir development by gas reservoir engineering method , including the analysis of gas reservoir productivity , 46 deep well classification and evaluation , initial and present non - resistance flow evaluation , 13 gas well decline law analysis , analysis of gas reservoir pressure system in Xiushan kiln , gas reservoir and anti - condensate saturation calculation of gas well , analysis of gas well unstable test well , etc .
On the basis of this , the feasibility analysis of gas injection of Chudong gas reservoir is carried out by combining the anti - condensation pollution experiment and the de - condensate pollution experiment , and the gas reservoir engineering research is carried out for six gas injection wells , and the gas injection parameters such as the total gas injection quantity , the daily gas injection quantity , the stewing time , the daily gas production amount and the injection period of the typical well group are established through numerical simulation .

The results show that the gas - gas reservoir has a higher average recovery rate of 0.1639mon - 1 and an average gas recovery rate of 0.1639mon - 1 , and the average recovery rate of gas wells is 0.1639mon - 1 . The average recovery rate of gas wells is 0.1639mon - 1 , and the average recovery rate of gas wells is 0.1639mon - 1 .
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE372

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