大庆油田聚合物驱交替注入方法研究

发布时间：2018-05-26 06:20

  本文选题：大庆油田 + 匹配关系　； 参考：《东北石油大学》2017年硕士论文

【摘要】：在实际的油藏中,由于油层纵向或平面上的非均质性,水驱过程中容易出现注入水的突进和指进现象,造成注入井周围不同方向的生产井受效不均匀,以及油层内部主流线和非主流线上对原油驱替的不均匀。聚合物等化学驱、化学剂调剖、调驱等技术可以大幅改善水驱效果,但仍然受油层非均质性的影响,这些方法应用后仍有大量剩余油在油层内呈不均匀状态分布,即定黏度的驱油剂与非均质的油层之间的矛盾仍然没有解决。论文采用恒速和恒压两种方法相结合的技术思路,将恒速注入计算出的阻力系数、残余阻力系数与恒压实验中得出的注入速度三个参数相结合,制定了驱油剂与油层注入界限的判定标准,总结了相互的匹配关系,并给出了配伍关系图版,得到了不同浓度,不同分子量聚合物与油藏匹配关系。之后在渗透率分别为100、300、500、700、900和1100×10-3μm2并联的6支人造岩心上,进行了聚合物交替变渗流阻力体系提高采收率的室内实验。通过对比不同交替方式和交替周期方案的分流率、采收率、含水率和压力等参数的变化,考察适合该非均质情况的交替变渗流阻力注入方式。研究发现,交替注入能够增加低渗层吸液量,调整吸液剖面,有效抑制注聚合物过程中剖面返转现象,从而改善非均质油层驱油效果,但交替周期存在一个最佳界限,就实验模拟的非均质油层而言,交替周期在0.2PV时可获得最佳驱油效果。对于交替注入的先后顺序,发现高浓高分聚合物在前的方式好于低分或低浓在前的方式,进而优选出了最佳聚合物交替变渗流阻力注入方式。通过含水、采收率、低渗层吸液比例等参数的对比说明,非均质情况下,交替周期段塞大小为0.2PV时,驱油效果好于交替周期为0.1PV和0.4PV的驱油方案;交替周期段塞大小为0.2PV时,驱油效果最好的交替顺序为先高分、高浓,后高分、普浓的交替顺序,注入量为2000PV·mg/L时聚驱采收率达到34.51%,最终采收率达到74.86%;高浓高分在前的交替顺序,好于低分或低浓在前的交替注入顺序。
[Abstract]:In the actual reservoir, due to the heterogeneity in the vertical or plane of the reservoir, it is easy to appear the phenomenon of injection water penetration and fingering in the process of water flooding, which results in the uneven effect of the production wells in different directions around the injection wells. And the inhomogeneous displacement of crude oil on the main and non-mainstream lines inside the reservoir. Chemical flooding, such as polymer flooding, profile control with chemical agents, flooding control and other techniques, can greatly improve the water drive effect, but it is still affected by reservoir heterogeneity. After the application of these methods, a large amount of remaining oil is still distributed unevenly in the reservoir. The contradiction between the constant viscosity flooding agent and the heterogeneous reservoir is still unresolved. In this paper, the method of constant velocity and constant pressure is used to combine the three parameters of constant velocity injection, residual resistance coefficient and constant pressure experiment. The criteria for determining the injection boundary between oil displacement agent and reservoir are established, and the matching relationship between oil displacement agent and reservoir is summarized. The matching relationship between different concentration and molecular weight polymer and reservoir is obtained. Then, an laboratory experiment was carried out on six artificial cores with permeability of 100300500700900 and 1100 脳 10 ~ (-3) 渭 m ~ (2) in parallel. By comparing the variation of the flow rate, recovery factor, water cut and pressure in different alternating modes and alternative periodic schemes, the alternative flow resistance injection mode suitable for the heterogeneous situation was investigated. It is found that alternating injection can increase the amount of liquid absorption in low permeability layer, adjust the absorption profile, and effectively suppress the phenomenon of section back shift in polymer injection process, thus improving the displacement effect of heterogeneous reservoirs, but there is an optimal limit of alternate cycle. For the heterogeneous reservoirs simulated experimentally, the best displacement effect can be obtained at 0.2PV. For the sequence of alternating injection, it is found that the way of high concentration and high content polymer is better than that of low score or low concentration, and the best alternative flow resistance injection mode of polymer is selected. The comparison of parameters such as water cut, oil recovery factor and liquid absorption ratio of low permeability layer shows that under heterogeneous condition, the displacement effect of alternating period slug with 0.2PV is better than that with alternate cycle of 0.1PV and 0.4PV, and with alternating period slug size of 0.2PV, the oil displacement effect is better than that of alternative cycle slug with 0.1PV and 0.4PV. The best alternating sequence of oil displacement effect is first high score, high concentration, later high score, common concentration alternating sequence. When the injection amount is 2000PV mg/L, the polymer flooding recovery factor reaches 34.51%, and the final recovery reaches 74.86%. Better than low score or low concentration at the front of the alternating injection sequence.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46
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本文编号：1936258