南海北部流花碳酸盐岩储层频域属性分析

生物礁碳酸盐岩油气藏储层具有丰度大、产能高的特点,一直以来是油气勘探重点探索的目标。南海北部大部分的油气发现均位于新近系,生物礁油气田也是该区勘探发现最大的亮点。其中东沙隆起区LH11生物礁是我国近年来发现的最大规模的同类型油气田。但其作为复杂的一类岩性油气藏,其非均质性和隐蔽性,使得在常规地震剖面上往往难以识别。本研究从地震频域属性角度出发,通过提取地震剖面频域图谱并结合测井孔隙度数据,分析生物礁储层频域特征,并结合正演模拟加以验证,认为研究区生物礁碳酸盐岩储层总体偏薄,导致了频率和衰减的异常,另外也证实薄层调谐效应方法可以较准确地估计层厚。

Spectral attribute analysis of Liuhua carbonate reservoir in the northern South China Sea

Reef carbonate reservoirs have been the focus of petroleum exploration for their abundance and high capacities. Most oil and gas discoveries in the northern South China Sea (SCS) have been located in Neogene, and the reef oil?gas field is the bright spot inside this area. Among reservoirs of this type, the LH11 reefs on the Dongsha uplift is the largest oil field discovered in China in recent years. However, as a typical lithological reservoir with high heterogeneity and intense concealment, it is often difficult to identify conventional seismic sections. Considering the seismic frequency domain attributes in this paper, we analyze spectral characteristics by extracting a series of seismic spectrograms and comparing them with porosity data to verify previous speculations with forward modeling. Based on our results, we consider the thin layer of the reservoir itself to be the primary reason for the abnormal frequency and attenuation. In addition, we confirm that the tuning effect can be used to estimate the thickness of thin reservoirs.