WS砂砾岩油藏能量补充方式研究

发布时间：2018-01-16 01:28

本文关键词：WS砂砾岩油藏能量补充方式研究　出处：《西南石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：WS砂砾岩油藏是一类被断层割裂开的复杂砂砾岩油藏,储层物性差,为低孔低渗或中低渗,且储层具有强非均质性。前期探索开发显示WS油藏具有复杂的压力系统和油水分布,初步的注水开发效果不明显。由于国内外有关相似油藏的开发均采用注水开发的方式,结合本油藏的特点,本文中,将进一步评价水驱开发的适应性,并在此基础上,探索WS砂砾岩油藏气驱的适应性,为现场注水注气补充能量方式的选择提供依据。为了解决以上问题,本文是以实验研究和数值模拟研究为主,并结合油藏工程方法,三者相结合,研究WS砂砾岩油藏补充能量方式。本文主要展开以下工作:(1)基于WS砂砾岩油藏区块初期开发的缘故,充分调研国内外相似砂砾岩油藏已经趋于成熟的开发方案和经验,为本油藏的进一步投产开发提供充分的现场依据;(2)通过PVT流体相态实验研究原油相态性质,并进一步运用ECLIPSE数模软件进行相态拟合;在此基础上分别模拟CO2、N2和伴生气注气膨胀,通过对比注入C02、N2和伴生气对原油饱和压力、粘度和原油膨胀系数的影响程度确定出CO2和伴生气的增溶效果明显,能有效的改善原油流动性能,为后面的注气方案选取注入气体介质提供依据;(3)进行细管实验,研究CO2、N2和伴生气三种注入气体的最小混相压力,得出结论为CO2最小混相压力小于伴生气,且均低于原始地层压力,为研究CO2和伴生气的混相驱替机理提供依据;(4)通过组合长岩心驱替研究比较水驱、CO2和伴生气三种不同注入方式的驱替效率,为选择注水和注气的驱替方式提供实验依据。最后,通过长岩心驱替实验结果得到,注入CO2在0.60HCPV时突破,突破时间最晚,且突破后油水同采期间的采出程度为14.92%,注CO2驱替最终采出程度为77.37%;注伴生气在0.43HCPV时突破,突破后共提采6.41%,最终采出程度为54.31%,由此可得出,注CO2驱替的效果最好,其次是伴生气驱替;(5)以WS油藏9井区储层非均质特性为基础,通过ECLIPSE数模软件建立起非均质性强弱不同的长岩心数值模拟,从而评价非均质性对驱替效率的影响;(6)充分运用油藏工程的方法,采用经验公式和类比法相结合的方式,初步论证了注水方案的开发技术政策,确定出初步的开发层系、井网井距以及注水量等,为后面注水方案的设计提供依据;(7)基于前面对气驱方式的评价研究,优选出适合气驱的井区,并对该井区进行注气开发技术政策的研究,通过论证和优化井网井距、注气时机、注入方式,对比注入介质、注入压力和注入量等参数,为最后注气方案的确定提供依据。
[Abstract]:WS sand gravel reservoir is a kind of complex sand gravel reservoir separated by fault. Its physical property is poor, which is low porosity, low permeability or low permeability. And the reservoir has strong heterogeneity. Early exploration and development show that WS reservoir has a complex pressure system and oil-water distribution. The initial effect of waterflooding development is not obvious. Because the development of similar reservoirs at home and abroad adopts the way of waterflooding development, combined with the characteristics of this reservoir, the adaptability of waterflooding development will be further evaluated in this paper. On the basis of this, the adaptability of gas drive in WS sand gravel reservoir is explored, which provides the basis for the selection of gas injection and gas injection in situ to supplement the energy, in order to solve the above problems. In this paper, the experimental research and numerical simulation are the main research, and combined with reservoir engineering methods, the three combined. The main work of this paper is as follows: 1) based on the initial development of WS sand and gravel reservoir block. The development plan and experience of similar sandy gravel reservoirs at home and abroad have been fully investigated, which provides sufficient field basis for further production and development of this reservoir. (2) the phase behavior of crude oil is studied by PVT fluid phase experiment, and the phase behavior fitting is carried out by using ECLIPSE software. On this basis, the expansion of CO _ 2N _ 2 and associated gas injection was simulated, and the saturation pressure of crude oil was compared by injection of C _ (02) N _ (2) and associated gas. The influence degree of viscosity and coefficient of expansion of crude oil determines that the solubilization effect of CO2 and associated gas is obvious, which can effectively improve the fluidity of crude oil and provide the basis for selecting the injected gas medium for the later gas injection scheme. The minimum miscible pressure of CO _ 2N _ 2 and associated gas injection gas is studied. It is concluded that the minimum miscibility pressure of CO2 is smaller than that of associated gas and is lower than that of original formation pressure. It provides the basis for studying the miscible displacement mechanism of CO2 and associated gas. 4) the displacement efficiency of three different injection modes of water drive CO _ 2 and associated gas is compared through the study of combined long core flooding, which provides experimental basis for selecting the displacement mode of water injection and gas injection. According to the experimental results of long core displacement, the breakthrough time of injection of CO2 at 0.60 HCPV is the latest, and the recovery degree of oil and water during the same production period after breakthrough is 14.92%. The final recovery degree of CO2 flooding is 77.37; The injection of associated gas broke through at 0.43 HCPV, after the breakthrough, 6.41 was extracted, and the final recovery degree was 54.31. It can be concluded that the effect of injecting CO2 displacement is the best, followed by associated gas displacement. Based on the heterogeneity of reservoir in WS 9 well area, the numerical simulation of long core with different heterogeneity is established by ECLIPSE software. The effect of heterogeneity on displacement efficiency is evaluated. Using reservoir engineering method, adopting experience formula and analogy method, the development technical policy of water injection scheme is preliminarily proved, and the preliminary development layer system is determined. Well spacing and water injection rate provide basis for the design of backwater injection scheme. Based on the previous research on the evaluation of gas drive mode, the well area suitable for gas drive is selected, and the technical policy of gas injection development in this well area is studied. Through the demonstration and optimization of well spacing, gas injection timing and injection mode. The parameters of injection medium, injection pressure and injection rate are compared to provide the basis for the determination of the final gas injection scheme.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE343

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