Tang Yong, Liao Songlin, Lei Xinhui, et al. Study on improving the sweep efficiency of CO2 flooding in low permeability fractured reservoirs in Huang-3 block[J]. Petroleum Reservoir Evaluation and Development, 2019, 9(3): 9-13.
DOI:
Tang Yong, Liao Songlin, Lei Xinhui, et al. Study on improving the sweep efficiency of CO2 flooding in low permeability fractured reservoirs in Huang-3 block[J]. Petroleum Reservoir Evaluation and Development, 2019, 9(3): 9-13. DOI: 10.13809/j.cnki.cn32-1825/te.2019.03.002.
Study on improving the sweep efficiency of CO2 flooding in low permeability fractured reservoirs in Huang-3 block
RF提高了1.8 %;优势通道井气窜早期关井效果较好;注水保持地层压力时其次;生产井GOR达到2 000 m
3
/m
3
时关井相对较差
RF仅提高0.11 %。研究成果对于低渗裂缝性油藏注气驱方案设计具有指导意义。
Abstract
A CO
2
flooding pilot test was carried out on the low permeability fractured reservoirs in Huang-3 block. The research results indicated that there were obvious oil-increasing effects in the overall area
but the gas channeling phenomenon was serious in some wells
resulting in a poor effect of CO
2
flooding. In order to improve the CO
2
flooding efficiency of low permeability fractured reservoirs
the dominant flow channels were identified by tracer monitoring combined with production dynamic analysis and numerical simulation of production history fitting. On this basis
a numerical simulation model of the well group considering the dominant channels was obtained. The effects of the dominant channels on the CO
2
displacement were studied by the numerical simulation technology of the component reservoirs
and four measures to improve the oil displacement efficiency were simulated. The results showed that the dominant channels reduced the CO
2
flooding oil recovery by 7 %. The best effect was obtained by blocking the dominant channels with high-intensity plugging measures
and the RF had increased by 1.8 %. The second best effect was when the dominant channels wells were shut down in the early stage of the gas channeling. Then followed when the water injection maintained the formation pressure. Shut in of the well was relatively poor when the GOR of production well reached 2 000 m
3
/m
3
and the RF only increased by 0.11 %. The research results have guiding significance for the design of gas injection drive scheme for low permeability fractured reservoirs.