裂缝-孔洞型凝析气藏不同开发方式的长岩心实验

柴达木盆地塔中Ⅰ号气田裂缝-孔洞型碳酸盐岩储层表现出“双孔双渗”特征，凝析油反蒸发机理不同于砂岩凝析气藏，国内外对如何提高裂缝-孔洞型凝析气藏采收率的研究还比较少。为此，首先取得无裂缝的碳酸盐岩岩心进行孔隙度和渗透率测试（平均孔隙度6.5%，平均渗透率1 mD），然后进行造缝（裂缝渗透率5~10 mD），并将岩心组合成长岩心（105.8 cm），最后采用塔中Ⅰ号气田凝析气（凝析油含量533 g/m³）进行了注气、吞吐和脉冲注气实验，优选出提高凝析油采收率的开发方式。实验结果表明：露点压力以上注气凝析油采收率最高，其次是最大凝析油饱和度下注气或脉冲注气；与低渗透砂岩凝析气藏不一样，注气吞吐提高凝析油采收率效果最差。该实验对裂缝-孔洞型储层高含凝析油型的凝析气藏的合理开发提供了技术支撑。

A long-core experimental study of different development schemes on fractured cavernous gas condensate reservoirs

The fractured cavernous carbonate reservoirs in the Tazhong-I Gas Field,Tarim Basin,present the characteristics of dual-porosity and dual-permeability,and the retrograde vaporization mechanism in this kind of reservoir is different from that in sand gas condensate reservoirs,and few studies have been found at home and abroad on how to improve the recovery of fractured cavernous gas condensate reservoirs.In this paper the porosity and permeability of the non-fractured carbonate cores were first measured(the ...