鄂尔多斯盆地石炭二叠系沉积特征与储集条件

SEDIMENTARY AND RESERVOIR CHARACTERS OF PERMOCARBONIFEROUS IN ORDOS BASIN

魏红红 彭惠群 李静群 谢正温

Wei Honghong Peng Huiqun Li Jingqun Xie Zhengwen

鄂尔多斯盆地石炭-二叠系形成于陆缘障壁海三角洲河流湖沼的沉积环境,自下而上构成一个由石英砂岩岩屑石英砂岩岩屑砂岩的沉积序列。本溪组、太原组、山西组、下石盒子组又各自由三个次一级的沉积序列组成。河道砂体和三角洲前缘砂体是有利于天然气富集的储集体,储集空间可归纳为:大孔粗喉型(Ⅰ)、大孔细喉型(Ⅱ)、小孔细喉型(Ⅲ)和细孔微喉型(Ⅳ)四类。Ⅰ类占11.91%,Ⅱ类占50.53%,Ⅲ类占28.06%,Ⅳ类占9.5%,工业气流一般都形成在前三类储层孔隙中。

The Carboniferous-Permian System in Ordos Basin was formed in marginal barrier seadeltariverlimnetic environment,and constitute a sedimentary sequence of silicarenitedetrital silicareniteclastic sandstone in ascending order.The Benxi,Taiyuan,Shanxi Formations of the System are composed respectively of three subsequences.River channel sandbodies and deltaic front sandbodies are favourable reservoirs for natural gas;the reservoir spaces of the reservoirs could be classfied into four types such as big pore coarse throat type(I),big pore fine throat type(Ⅱ),small pore fine throat type(Ⅲ)and fine proe minimal throat ytpe(Ⅳ).Among them,type I occupies 11.19%,type Ⅱ occupies 50.53%,type Ⅲ occupies 28.06% and type Ⅳ occupies 9.5%.Commercial gas flows are usually preserved in the first three types.

10.11743/ogg19980210