塔里木油田碳酸盐岩大尺度溶洞油藏试井新模型研究

A New Well Test Interpretation Model for the Large Scale Karst Cave Carbonate Reservoir in Tarim Oilfield

针对塔里木油田岩溶碳酸盐岩油气藏,建立并求解大尺度溶洞两区复合油藏模型,绘制试井双对数典型曲线,并与常规试井曲线进行对比分析,最后用实例井进行验证。研究表明,大尺度溶洞碳酸盐岩油藏试井典型曲线与常规复合油藏基本相同,不同之处在于,大尺度溶洞油藏压力导数曲线出现多个凹陷,凹子的深浅受溶洞的大小及与井筒距离控制,一般地,溶洞越大、离井筒距离越近,凹子将越深。将裂缝孔洞渗流与大型溶洞"空腔流"结合来建立试井模型,弥补前人建立的大尺度溶洞试井模型的缺陷,可为大型溶洞碳酸盐岩油气藏勘探开发提供理论支持。

According to the karst carbonate reservoir in Tarim oilfield,the well test interpretation models for the large scale karst cave composite reservoir were established and solved. Then,the well test typical log-log curves were drawn and compared with conventional well test curves. Finally,the reliability of the models is verified with a practical example. The result indicated that the well test typical curves of large scale vuggy carbonate reservoir are fundamentally the same as the conventional composite reservoir. That makes their different is that multiple concave might be appeared on the pressure derivative curves of large-scale karst cave reservoir,and the depth of the concave would be affected by the scale of the karst cave and the distance of cave with well-bore. Generally,the larger and nearer the cave,the concave would be deeper. Combined seepage flow in facture and vug with 'cavity flow' in large scale cave,the well test models would make up for the defects in the previous large-scale karst cave models,and would provide theoretical support to large scale cave carbonate reservoir exploration and development.