柴达木盆地中东部地区储层特征与天然气成藏条件

柴达木盆地中东部地区第四第七个泉组是重要的储集层，也是主要的产气层段。通过研究储层的沉积特征以及气藏形成条件认为：（）储集层的岩石粒度普遍较细，以粉砂岩、泥质粉砂岩为主，属滨浅湖沉积体系；（2）储集层成岩程度低，岩石结构松散，原生孔隙发育并具有良好的渗透性；（3）在第四纪更新统湖盆总体上经历了扩张－稳定－收缩的变化过程，因而沉积相在垂向上表现为滨湖、浅湖、较深湖的相互交替；（4）研究区的气藏具有自生、自储、自盖的特点，产气层主要分布于K2－K10层段。

CHARACTERISTICS OF RESERVOIR AND THE FORMING CONDITION OF GAS RESERVOIR IN MIDDLE-EAST AREA OF CHAIDAMU BASIN

The Qigequan formation is one of the important reservoirs and the important layers that produce gas. Based on the study of depositional characteristics and forming condition of gas pool we can concluded that: (1) Rock granularity of the reservoir is generally. very fine and mudbearing siltstone, which belong to a shore shallow lake sedimentation system. (2) Diagenetic degree of the reservoir rocks is very low so primary porosity of rock is well developed and have excellent permeability. (3) In the Quaternary system, Pleistocene series, lake basin underwent a changeable process of expanding, stabilizing and shrinking. So the sedimentary facies of shore lake, shallow lake, and deeper lake are joint each other vertically. (4) The gas reservoirs in the study area have the characteristic of generating itself, storaging itself and enveloping itself, and primary reservoirs exist in K 2 -K 10 .