低渗透应力敏感性油藏的合理开发

发布时间：2018-02-01 15:15

本文关键词： 低渗透储层应力敏感性不可逆单井产油量生产压差　出处：《油气地质与采收率》2017年04期 　论文类型：期刊论文

【摘要】：针对低渗透油藏开发效果难以达到预期的现象,通过采用变流体压力应力敏感实验方法,保持围压不变对某低渗透油藏的岩心在不同流体压力下的渗透率进行测试。研究结果表明:随着流体压力的减小,岩心渗透率逐渐降低,但减小幅度趋于平缓;岩石渗透率越低,应力敏感性越强,流体压力恢复后,岩心渗透率并不能恢复到原来水平,其原因是低渗透岩石应力敏感性是不可逆的。利用径向渗流理论,结合应力敏感性对渗透率的影响,建立新的油井产能方程,计算出地层压力变化对单井产能的影响。在保持生产压差为4 MPa不变的前提下,地层压力下降5MPa,单井的产能降低10%~30%,储层渗透率越低,降幅越大。为使低渗透应力敏感性油藏得到合理高效的开发,储层在进行压裂、射孔和作业过程中需注意油层保护;在开采过程中需观察井底流压的变化,维持合理的生产压差;当油井产油量明显下降后,适时对近井地带储层进行酸化,增大近井地带的渗透率。
[Abstract]:In view of the phenomenon that the development effect of low permeability reservoir is difficult to achieve the expected results, the method of variable fluid pressure and stress sensitivity experiment is adopted. The permeability of the core of a low permeability reservoir under different fluid pressures is tested by keeping the confining pressure unchanged. The results show that with the decrease of fluid pressure, the core permeability decreases gradually, but the decrease tends to be gentle; The lower the permeability of rock, the stronger the stress sensitivity. After the fluid pressure recovers, the core permeability can not return to the original level, the reason is that the stress sensitivity of low permeability rock is irreversible. Combined with the effect of stress sensitivity on permeability, a new well productivity equation is established, and the influence of formation pressure change on single well productivity is calculated. The production pressure difference is kept constant at 4 MPa. Formation pressure is reduced by 5 MPa, productivity of single well is reduced by 10% and 30%, the lower the reservoir permeability is, the greater the decrease is. In order to make the low permeability stress sensitive reservoir develop reasonably and efficiently, the reservoir is fracturing. Pay attention to reservoir protection during perforation and operation; In the process of mining, the change of bottom hole flow pressure should be observed to maintain reasonable production pressure difference. When the oil production decreases obviously, the near well zone reservoir is acidified at the right time, and the permeability of the near well zone is increased.
【作者单位】：西南石油大学石油与天然气工程学院;
【分类号】：TE348
【正文快照】： ——低渗透储层开发过程中如何提高单井产能是油气开发难题。单井产能主要由岩石渗透率决定,而低渗透储层除本身孔隙结构、岩石骨架特征导致渗透率低之外,在开发过程中岩石会表现出明显的应力敏感性,随着油藏内压力下降,微小孔道闭合,渗透率进一步下降[1],导致开发难度增大

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