龙岗地区礁滩气藏地质建模方法探索

针对四川盆地龙岗地区礁滩储层非均质性强及气藏气水关系复杂、地质建模存在诸多技术难题的现状，开展了三维地质建模的探索工作，并总结形成了以“双相控制，分步建模”技术方法为核心的复杂礁滩气藏建模技术。其建模思路及技术对策为：①突破等时地层界面，以储渗体为研究单元；②沉积相建模确定气藏大的沉积背景及格局；③确定岩性在空间的分布规律，精细刻画储渗体空间的非均质性；④采用局部建模与整体建模相结合的分步建模方法；⑤采用随机与确定性建模相结合的技术方法。模型验证结果表明，该建模技术适用于龙岗地区以及稀井网条件下储层非均质性强、气水关系复杂的礁滩型碳酸盐岩气藏的整体描述。

Geological modeling of reef-bank gas reservoirs in the Longgang Gas Field,Sichuan Basin

In view of the strong heterogeneity of reef-bank reservoirs and the complexity of gas-water contact in the Longgang area,Sichuan Basin,and technical challenges bottlenecking geological modeling,we discussed 3D geological modeling methods and developed a modeling procedure with "dual phase controlling and step modeling" as its core for complex reef-bank gas reservoirs.Its ideas and technical solutions are presented as follows:(1) breaking through the constraint of isochronous sequence boundaries and taking reservoir body as the study unit;(2) defining depositional setting and framework of gas reservoirs through sedimentary facies modeling;(3) determining the spatial distribution pattern of lithology and characterizing in detail the heterogeneity of reservoir space;(4) applying the step modeling method which incorporates local modeling with overall modeling;(5) integrating stochastic modeling with deterministic modeling.Model verification shows that this technique is suitable for the overall modeling of reef-bank gas reservoirs with strong heterogeneity and complex gas-water contact in the Longgang field and other areas with sparse well patterns.