摘要
在四川盆地东部古生界地层发现大量天然气资源，鲜有原油发现。重庆天府磨心坡煤矿下二叠统茅口组石灰岩上部地层裂隙发现沿层间裂隙随水渗出的黄绿色液态轻质油苗。研究表明：油苗碳数分布较窄，为C4-C26，具有明显的姥鲛烷优势，Pr／Ph值为1．64，δ13C值为-26．2％；油苗所反映的成熟度较高，折算凡约为1．6％，一维盆地模拟验证二叠系的热演化程度可达与之相当的热演化程度。综合研究认为油苗与二叠系煤系地层关系密切。油苗的发现表明，在四川盆地古生界整体高过成熟的大背景下，某些成熟度相对较低。保存条件适宜的区域仍有发现一些中小型油藏的可能，这对四川乃至南方古生界油气勘探具有一定的启示意义。
There is abundant natural gas but less oB accumulaSon in Palaeozoic and Triassic marine reservoins in the east part of Sichuan Basin. Recently,some yelow greenish rcjht crude oil ,show was discovered in fissures of marine Lower Permian Maokou limestone at Moxinpo Coal Mine in Chongqing. The oil has been anelyzed by a series of geological and ozjanic geochemistry methods. The distribution of n-alkane in aliphatic fraction of the oil ranges from n-C4 to n-C=withobviouspdstane preference （Pr/Ph=1.64）. RelativelyhighRo （about1.6%） of the calcutated oil matudty is consistentwiththe measured Wottte reffectance of the Pertain coal at Moxinpo. The δ13C -26.2%, which is similar to those from Permian Longtan shale and coal. It is considered that the oil in limestone fissures is mostly dedved from the marine Permian coal measure strata, including some contributions of continental organic matter. The accumulation of the hydrocarbon needs to be further studied. The discovery of the oil show hints possible industrial accumulalion in some relative low mature reserviors among high mature areas of Sichuan Basin.
出处
《海相油气地质》
2010年第1期44-50,共7页
Marine Origin Petroleum Geology
