顶部注气重力驱技术在底水油藏应用探讨

Application of Top Gas Injection-Assisted Gravity Drainage in Bottom Water Reservoirs

顶部注气重力驱技术在国内油田现场应用仍处于"摸石头过河"探索阶段。通过综合考虑油藏地质参数、开发参数等方面因素,初步定性、定量建立了适合注气重力驱油藏筛选条件,并以国内首个开展实施顶部注气重力驱技术的西部某底水砂岩油藏为例,结合油藏工程法、数值模拟法、现场动态及监测结果等开展注气重力驱油藏方案要点、估算注气规模、开井时机优选及气液界面稳定性研究,论述了注气重力驱关键技术注入优化控制技术、生产井开关井控制技术、注采优化射孔技术、动态跟踪及调整技术,最后,针对控制气液界面稳定性提出"注采兼顾、分区控压限产、追踪界面调整"开发技术政策。

The application of top gas injection-assisted gravity drainage technology in domestic oilfields is still in the exploratory stage. Based on the comprehensive consideration of the formation's geological parameters, development parameters, and other factors, preliminary qualitative and quantitative screening conditions for identifying reservoirs suitable for gas-assisted gravity drainage were established. A bottom water sandstone oil reservoir in the western part of China, where top gas injection-assisted gravity drainage technology was implemented for the first time first in China, was used as an example. Combined with the reservoir engineering method, numerical simulation method, field dynamics, and monitoring results, studies on the key points of gas-assisted gravity drainage reservoirs, estimation of gas injection scale, optimization of well opening timing, and stability of the gas-liquid interface were carried out. Key technologies of gas-assisted gravity drainage technology were discussed,including injection optimization control technology, production well switch and control technology, injection and production optimization perforation technology, dynamic tracking, and adjustment technology. Finally, for the control of gas-liquid interface stability, the technology policy was proposed that recommended focusing on both injection and production, zoning to control pressure and limit production, and tracking interface adjustment.