歧口凹陷湖相碳酸盐岩储层岩性识别及储集类型研究

On Lithology Identification of Limnetic Facies Carbonate Reservoir in Qikou Sag and Its Reservoir Types

歧口凹陷湖相碳酸盐岩油藏储层横向分布广泛,纵向发育稳定。该类储层岩性多样,主要岩性为白云岩及生屑灰岩等,储集空间复杂。通过对歧口凹陷沙一下段湖相碳酸盐岩储层不同岩性测井响应特征的分析,提出了利用测井响应特征及岩性敏感系数交会图法快速识别岩性的方法。应用岩性指数曲线有效识别岩性,结合这些特征对不同类型的湖相碳酸盐储层进行划分,形成了一套利用测井资料评价湖相碳酸盐岩的方法。

Lacustrine carbonate reservoir in Qikou sag is characterized by stable longitudinal de- velopment and wide transverse distribution. In the sag, reservoir lithologies are various and main lithologies are dolomites and born flocks limestones, etc. Reservoir space in the sag is also com- plex. On the basis of analysing lithology log responses of different lacustrine carbonate reservoirs in the sag, proposed is a method to use log response characteristics ＆~ lithology sensitive coeffi- cient crossplot quickly recognize the lithologies. Lithology index curve is effective in lithology i- dentification. According to core data and geologic classification method, the above reservoirs may be classified into two types, pore-fracture reservoir and pore reservoir. An initiative method is formed for lacustrine carbonate reservoir identification with log data.