针对渤海海域在烃源岩总有机碳质量分数(w (TOC))研究中难以反映其垂向连续变化的问题,利用改进的ΔlgR法对其进行系统研究。研究认为,沙南凹陷发育沙河街组三段、二段、一段和东营组三段4套有效烃源岩,总厚度可超过500 m,具有良好的生烃能力。但不同时期烃源岩的w (TOC)变化较大。其中,沙三段中、早期和沙一段沉积时期形成的烃源岩中有机质尤为富集,w (TOC)均大于2%,最高可达10%。
In allusion to the problem being difficult to reflect the vertical continuous change of total organic carbon (w (TOC)) in the study of Bohai Bay basin, the improved ΔlgR method was deployed for a systematical study of it. Study shows that in Shanan Sag there develop 4 sets of effective source rocks, such as Es3, Es2 and Es1 and Ed3; their total thickness is over 500 m and it has good hydrocarbon generation capacity. However, the w (TOC) of source rocks varies greatly in different periods. Among them, the organic matter in the source rock, which is formed during the mid and early stage of sediment, is especially rich, and w (TOC) is more than 2%, up to 10%.