【摘要】 塔里木盆地北部坳陷周缘发现的大量油气主要来源于下寒武统泥质烃源岩。坳陷西部下寒武统发育玉尔吐斯组,东部发育西大山和西山布拉克组,两者在有机质丰度、类型和成熟度等方面存在明显不同,微量元素显示玉尔吐斯组具有较高的古生产力,总体反映西部水体较深的强还原斜坡相沉积环境,而东部则反映为水体更深、还原程度更高的盆地相沉积环境。通过地震标定及解释,刻画了下寒武统烃源岩厚度图,发现了满西、满东两个沉积凹陷,结合总有机碳(TOC)分布图,对下寒武统烃源岩生烃潜力进行了计算及成图。北部坳陷生烃量巨大,而目前已发现油气仅占很小一部分,所以北部坳陷及周缘下步勘探潜力巨大。更多还原

【Abstract】 A great quantity of oil and gas has been found in the periphery of the Northern Depression in the Tarim Basin, which was primarily derived from Lower Cambrian source rocks. These Lower Cambrian source rocks comprise the Yuertusi Formation in the west and the Xidashan-Xishabulake Formation in the East. Several differences were observed between the formations, including total organic carbon content(TOC), kerogen types, and maturities. Biomarker composition and life trace elemental concentration demonstrated that the Lower Cambrian source rocks were deposited in a strong reducing slope environment in the west but in a deeper and stronger reducing basin environment in the east. Isopaches for the source rocks demonstrated that there were two depositional sags at Manxi and Mandong in the Northern Depression, which were plotted based on seismic tracing and interpretation. Hydrocarbon generative potential for the source rocks was estimated based on the contours of thickness and the TOC in the Northern Depression. The amount of oil that has been found to date only accounts for a small portion of this estimate, suggesting that a huge amount of oil remains undiscovered in the depression.更多还原