摘要: |
为了研究复杂裂缝性致密油藏注水吞吐机制和开发规律,基于嵌入式离散裂缝模型,建立考虑应力敏感和启动压力梯度效应的油水两相渗流模型及数值模拟方法,并分析应力敏感、启动压力梯度及注水吞吐参数对开发的影响。结果表明:应力敏感和启动压力梯度效应会降低致密油藏的开发效果;随吞吐轮次的增加,开发效果变差;焖井时间的增加会使相同吞吐轮次下的产油量增加,但平均采油速度降低;注入速度的增加对提高吞吐开发的效果最为显著;提出的模型和计算方法可用于计算复杂裂缝形态下致密油藏开发,提供更加准确的指导。 |
关键词: 致密油藏 复杂裂缝 注水吞吐 数值模拟 |
DOI:10.3969/j.issn.1673-5005.2019.05.012 |
分类号::TE 319; TE 348 |
文献标识码:A |
基金项目:国家自然科学基金项目(51504276,7, 51490654) |
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Numerical simulation and mechanism analysis of water huff and puff process in complex fractured tight oil reservoirs |
YAO Jun, LIU Lijun, SUN Hai, LI Aifen
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(School of Petroleum Engineering in China University of Petroleum (East China), Qingdao 266580, China)
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Abstract: |
In order to investigate the mechanisms and production patterns involved in water huff and puff process for oil production in tight oil reservoirs, a water-oil two-phase flow model with stress sensitivity and threshold pressure gradient was proposed, and its corresponding numerical simulation methods were described based on an embedded discrete fracture model. The effects of the stress sensitivity, the threshold pressure gradient and the huff-puff operation parameters on oil production were investigated. The numerical simulation results show that stress sensitivity and threshold pressure gradient can reduce oil production in tight oil reservoirs. The production rate declines with the increase of the cyclic numbers. The increase of water soaking time in the reservoir can increase oil production, while the average oil recovery rate can be decreased. The increase of water injection rate has the most significant enhancement on oil production. The proposed model and its computational method can be effectively used for the numerical simulation study of the complex fractured tight oil reservoirs. |
Key words: tight oil reservoir complex fracture water huff and puff numerical simulation |