准噶尔盆地天然气藏地质特征及分布规律

准噶尔盆地迄 今没有发现高产、高丰度的大中型气田,其主要原因是缺乏储集层厚度大、储集性能好、闭合度高与闭合面积大的大型圈闭。准噶尔盆地天然气藏分布的基本规律是:①气源区明显控制着气藏的地理及层系分布,天然气比石油更为近源分布;②伸入烃源区的凸起等正向构造是天然气主要汇聚区:③沟通气源的断裂控制着气藏分布:④区域盖层和储集层共同决定了气藏在垂向上的分布。在上述认识的基础上,指出了准噶尔盆地天然气勘探应该遵循的原则和有利的勘探方向,认为莫索湾、东湾和玛湖背斜等大型背斜构造,应作为天然气勘探的重点目标。

Geologic Characteristics and Distribution Framework of Natural Gas Reservoirs in Junggar Basin

The principle reasons for no large- and middle- scale natural gas fields with high yield and high enrichment up to now have been found in Junggar basin could be lack of large- scale traps with great thickness and good quality of gas reservoirs as well as high closure and big closed area. The study shows that the fundamental distri bution regularities of the gas reservoirs are as fallows:①The geographic and stratigraphic distribution of gas pools are obv iously controlled by the gas source region, showing that natural gas is much more closely distribution nearby the source region than crude oil;②Normal structures like arch stretching hydrocarbon source region should be main accumulating area;③It is faulting connected with gas source that controlled gas pool's distribution;④Regional cap rock and reservoir rock determined its profile distribution. Based on these knowledge, this paper presents the principles that should be followed and favorable exploratory directions for gas prospecting in Junggar basin. It is believed that these large scale anticline structures such as Mosuowan, Dongwan and Mahu anticline should be as important targets for the gas exploration.