稠油蒸汽驱方案设计及跟踪调整四项基本准则

利用数值模拟方法研究注汽速率、井底蒸汽干度、采注比及油藏压力对稠油油藏蒸汽驱开发效果的影响，给出了具体的量化指标范围。研究结果表明，对于普通稠油油藏，要达到较好的蒸汽驱开发效果，必须满足以下条件：①注汽速率大于等于1．6m^3／（d·hm^2·m），从而保持蒸汽带的不断扩展，并保持井底蒸汽干度；②井底蒸汽干度大于等于40％，反映蒸汽驱对单位注入流体热焙的要求；③油藏压力小于5．0MPa，最好为1．0～3．0MPa，保持较低的油藏压力可提高蒸汽波及体积；④蒸汽驱稳定阶段的瞬时采注比大于等于1．2，才能真正实现蒸汽驱。辽河油田齐40块蒸汽驱先导试验和扩大试验的方案设计、跟踪调整及评价表明，提出的有关量化指标已成为蒸汽驱方案设计、跟踪调整和评价的四项基本准则。图6表1参10

Four fundamental principles for design and follow-up of steam flooding in heavy oil reservoirs

Numerical simulation is used to understand the impacts of steam injection rate, bottom-hole steam quality, production/injection ratio and reservoir pressure on the performance of steam flooding in heavy oil reservoirs, providing the concrete ranges of quantified indices. For conventional heavy oil reservoirs, to realize better performance by steam flooding, the following conditions must be met: (1)steam injection rate should not be less than 1.6 m3/(d·hm2·m), thus keeping the continuous extension of steam chamber and maintaining the bottom hole steam quality; (2)bottom hole steam quality should not be less than 40%, which reflects the requirement of enthalpy for unit injected fluid by steam flooding; (3)reservoir pressure should be less than 5.0 MPa, had better in 1.0-3.0 MPa, thus maintaining a lower reservoir pressure to improve the swept volume of steam; (4)instant production/injection ratio should not be less than 1.2 during the stable stage of steam flooding, realizing practical steam flooding. The design, follow-up and evaluation of steam flooding in pilot test and extension test in Qi40 Block of Liaohe Oilfield show that the quantified indices have become four fundamental principles for such design, follow-up and evaluation.