鄂尔多斯盆地上古生界气藏与深盆气藏成藏机理之辩析  

DISCUSSION ON RELATION OF GAS ACCUMULATION MECHANISM BETWEEN DEEP BASIN AND UPPER PALEOZOIC IN THE ORDOS BASIN

作　　者：李仲东[1] 郝蜀民[2] 惠宽洋[2] 李良[2] 过敏[1] 

机构地区：[1]成都理工大学'油气藏地质及开发工程'国家重点实验室,四川成都610059 [2]中国石化集团公司华北分公司,河南郑州450006

出　　处：《矿物岩石》2009年第1期86-92,共7页Mineralogy and Petrology

摘　　要：通过时鄂尔多斯盆地上古生界气藏形成基本条件、气水分布规律和成藏动力学特征研究分析，并与北美典型深盆气进行对比发现，如果仅从气源丰富、储层致密、异常压力、大面积含气等气藏表现特征观察。上古生界气藏与典型深盆气藏极为相似。但从各区气藏形成条件来看，上古生界烃源岩生气速率慢，持续地供气条件较差；气藏上倾方向多因物性或岩性封挡，主要表现为非均质储层条件下的岩性和构造-岩性气藏类型；含气范围内的同一气层连通性较差，气水分布受区域构造控制，局部明显存在边底水，也没有整体活塞式气驱水作用形成的区域性气水界面。成藏动力学机理反映，上古生界储层毛细管阻力过大，天然气二次运移的浮力不够，主要是就近运移聚集成藏，没有大规模运移的迹象，难以实现整体活塞式气驱水运移。所以用深盆气藏成藏机理还不能合理解释鄂尔多斯盆地上古生界气藏成因。综合分析认为，持续供气能力不够、储层连通性差是造成上古生界气藏有别于深盆气藏的主要原因。The relation between gas accumulation of typical deep basin gas and Upper Paleozoic gas field in the Ordos basin was studied in detail on the basis of analysis of sandstone and shale compaction, evolution of porosity, mechanism of pressure formation, distribution of gas and water,gas migration and gas accumulation, as well as in combination with previous research. The characteristics of deep basin gas trap and Upper Paleozoic gas field were similar from the aspects of abundant accumulation, abnormal pressure, large scale gas accumulation and compacted reservoir. However, it was showed that the generation rates of gas was low with poor condition of continuous gas supply in the Upper Paleozoic hydrocarbon rocks,and the migration of gas was prevented by either rock property or lithology, forming lithologic gas reservoir or structural-lithologic gas reservoir in the condition of heterogeneous reservoir. Dynamic analysis of gas formation revealed that the resisting force for the capillary tubes in the Upper Paleozoic reservoir was so high that it prevented the remigration of gas. In fact, the gas only migrated in a very short way and then accumulated. Therefore, the gas accumulation mechanism for deep basin was not suitable for the interpretation of the genesis of the Upper Paleozoic gas pool in the Ordos .basin. Comprehensive analysis indicated that the low capacity of continuous gas supply and poor connection of reservoir were the major factors differing the deep basin gas pool from the Upper Paleozoic gas pool in the Ordos basin.

关 键 词：鄂尔多斯盆地 上古生界 成藏特征 与深盆气藏对比 成藏机理 

分 类 号：TE122.3[石油与天然气工程—油气勘探]