丘东凝析气藏开发中后期提高采收率实验研究

发布时间：2018-04-30 22:21

本文选题：凝析气藏 + 提高采收率　；参考：《西南石油大学》2015年硕士论文

【摘要】：凝析气田因其可观的储量和极高的经济价值,在我国乃至世界气田开发中占有重要地位。而目前我国相当部分凝析气田已进入开发中后期且大多由于严重的反凝析污染而处于低产低效状态,因此探索凝析气藏开发中后期如何提高凝析油采收率对凝析气藏开发具有非常重要意义。本论文在中石油“凝析气藏开发中后期提高采收率机理及技术可行性”项目的资助下开展实验研究,对指导凝析气藏合理高效开发具有重要意义。丘东凝析气藏属于中等凝析油含量的低渗气藏。开发进入中后期,凝析油和天然气采收率较低。本文通过在室内配制有地层代表性的流体并开展凝析气体系注气膨胀实验,研究不同注入介质、不同注入压力条件下对反凝析液的抽提规律。在此基础上采用实际储层岩心,在室内开展长岩心驱替实验模拟凝析气藏开发中后期不同注入流体、不同注气方式条件下提高凝析油采出程度的差异以及储层层间物性差异对注气效果的影响,并结合实际优选出合适注入流体和注气方式,同时定量评价了层间干扰对注气效果的影响。本文主要取得了以下结论与认识： (1)注气膨胀实验结果表明：目前地层压力下,CO2对反凝析液的抽提能力最强、其次为干气,N2最弱;注气压力越高,对反凝析液抽提能力越强。 (2)不同注入流体长岩心实验表明：目前地层压力下注干气驱凝析油累计采收率可达到38.68%,且总注入量较少(2.6HCPV),故考虑干气为补充地层能量的首选介质。 (3)不同注气方式长岩心实验表明：目前地层压力下脉冲注气凝析油采出程度达到64.96%,但注入量高达4.51HCPV;其次是连续气驱,凝析油采出程度达到38.68%,注入量2.04HCPV。故针对丘东凝析气田,建议首先选择连续气驱开发方式,气量充足的情况下可选择脉冲注气。 (4)层间干扰实验结果表明：笼统注气时,高渗层凝析油采出程度增加迅速且大于低渗层。与分层注气比较,相同注气速度下注入相同体积气量1.48HCPV时,笼统注气比分层注气凝析油采出程度低5.77%。
[Abstract]:Condensate gas field plays an important role in gas field development in China and the world because of its considerable reserves and high economic value. However, at present, quite a part of condensate gas fields in China have entered the middle and late stage of development, and most of them are in a state of low productivity and low efficiency due to serious retrograde condensate pollution. Therefore, it is very important to explore how to improve condensate oil recovery in the middle and late stage of development of condensate gas reservoir. This paper is of great significance to guide the rational and efficient development of condensate gas reservoir with the support of PetroChina project "improving recovery mechanism and technical feasibility in the middle and late stage of development of condensate gas reservoir". Qiudong condensate gas reservoir belongs to low permeability gas reservoir with medium condensate content. The recovery of condensate oil and natural gas is low in the middle and late stage of development. In this paper, the extraction law of reverse condensate was studied under different injection medium and different injection pressure through the preparation of stratigraphic representative fluid and the gas injection expansion experiment of condensate gas system. On this basis, the actual reservoir core is used to simulate the different injection fluid in the middle and late stage of condensate gas reservoir development by using long core displacement experiment in laboratory. The effects of different gas injection modes on the gas injection effect are discussed, and the suitable injection fluid and gas injection mode are selected according to the different gas injection modes, as well as the effect of reservoir physical property difference on the gas injection effect. At the same time, the effect of interlayer interference on gas injection effect was evaluated quantitatively. In this paper, the following conclusions and understandings are obtained: 1) the results of gas injection expansion test show that CO _ 2 has the strongest extraction ability to reverse condensate at present, followed by the weakest dry gas N _ 2, and the higher the gas injection pressure, the stronger the extraction ability of reverse condensate. 2) the long core experiments of different injected fluids show that the cumulative recovery factor of condensate oil driven by dry gas flooding can reach 38.68 at present, and the total injection quantity is less than 2.6 HCPVN, so the dry gas is considered as the preferred medium to replenish the formation energy. 3) long core experiments of different gas injection modes show that the recovery degree of condensate oil by pulsed gas injection is 64.96 at present, but the injection rate is as high as 4.51 HCPV.The second is continuous gas drive, the recovery degree of condensate oil is 38.68 and the injection quantity is 2.04HCPV. Therefore, for Qiudong condensate gas field, it is suggested that continuous gas drive should be selected first, and pulse gas injection should be selected when gas quantity is sufficient. The experimental results of interlaminar interference show that the recovery degree of condensate oil in high permeability layer increases rapidly and is larger than that in low permeability layer under general gas injection. Compared with stratified gas injection, the recovery degree of general gas injection is 5.77% lower than that of stratified gas injection condensate oil under the same gas injection velocity and same volume gas volume 1.48HCPV.
【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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