塔东2井古油藏成藏期分析  

Timing of paleo-oil accumulation in Tadong No. 2 Well, Tarim Basin

作　　者：孙玉善[1] 金英爱[1] 顾乔元[1] 申银民[1] 杨帆[1] 

机构地区：[1]中国石油塔里木油田勘探开发研究院

出　　处：《石油勘探与开发》2003年第5期31-33,61,共4页Petroleum Exploration and Development

摘　　要：塔里木盆地塔东低凸起的塔东2井在寒武系一下奥陶统获得少量重质油,发现寒武系一下奥陶统碳酸盐岩是优质烃源岩,其中的有机质和沥青赋存产状大致有3种:①基质中的大量黑色炭化的有机(泥)质;②收缩溶蚀缝脉和Ⅰ期构造溶蚀缝脉及晶间溶蚀孔中的黑色炭质沥青;③局部Ⅲ期构造缝中的油质-胶质沥青。根据沥青的产状,结合碳酸盐岩成岩演化序列与其成岩阶段和构造演化史,认为塔东2井油藏为两期成藏,烃源岩在奥陶纪末的早成岩末至晚成岩早期阶段就已排烃形成早期油藏,志留纪末进入晚成岩深埋藏阶段,古油藏因高温热蚀变遭破坏;晚期成藏在海西—印支期以来,经同层调整后再次成藏,属自生自储的残余古油藏。The Cambrian and the Lower Ordovician in Tadong No. 2 Well in the East Tarim Basin produces some amount of heavy oil. There are three types of occurrence of organic material and bitumen: ① carbonized argillaceous black organic matter in rock matrix; ② black carbenes in dissolution veins/ fractures due to compaction or primary structural compression, and inter-crystal pores from dissolution; and ③ oil bitumen in localized fractures formed during the later structural deformation. Based on bitumen occurrence, carbonate diagenetic sequence and stage, and tectonic history, it is likely that the accumulation of paleo-oil in Tadong No. 2 Well took place in two separate periods. The earliest oil was accumulated in the late early to early late carbonate diagenesis near the end of Ordovician. This early palaeo-oil was then destroyed in Late Silurian due to high temperature degradation. The present oil was first formed in the latest Silurian and then it has gone through stratal modification since the Late Paleozoic.

关 键 词：塔东2井 寒武系-下奥陶统 古油藏 沥青产状 成岩演化序列 成藏期 

分 类 号：TE122.1[石油与天然气工程—油气勘探]