摘要
鄂尔多斯盆地中东部下二叠统山西组2段为重要的勘探层位和主力产气层。在野外露头分析、岩心观察、测井资料综合解释以及地球化学分析的基础上,研究认为山西组2段早中期研究区受海相作用影响,山32、山22期发育河控—潮控三角洲,其三角洲平原包括分流河道、废弃河道、泥炭沼泽和分流间洼地,三角洲前缘包括水下分流河道、河口坝、远砂坝、潮汐砂坝、分流间湾等沉积微相;山12期海水沿东南方向推出鄂尔多斯盆地,研究区在陆相湖泊背景上发育河控—湖泊三角洲。古地理条件的不同使其砂体类型及储集性能也有一定的差异,其中米脂—子洲及塔湾—高桥地区山32段储集砂体受海相环境改造彻底,在岩性特征、砂体厚度以及储集性能方面更具优越性,为天然气勘探的有利目标区。
The member 2 of Lower Permian Shanxi formation is a main gas-producing reservoir and an important layer for exploration in the mid- eastern Ordos Basin. Outcrop analysis, core observation, comprehensive logging data interpretation and geochemical analysis suggest that the study area was affected by Marine facies at the early-middle stage of member 2 of Shanxi formation. It developed a rivertide controlled delta at the 2 and 3 sub- member of member 2 of Shanxi formation. The delta plain included distributary channel,abandoned channel, peat swamps and interdistributary depression. The delta front included sedimentary micro-facies, such as underwater distributary channel, mouth bar, distal bar, tide sand dam, and interdistributary bay. Seawater pushed out along the southeast Ordos Basin in the age of the 1 sub- member of member 2 of Shanxi formation. The study area developed a river controlled- lake delta on the background of terrestrial lakes. The differences of ancient geographical conditions lead to the different types of sand and reservoir properties. The reservoir sand in the 3 sub-member of member 2 of Shanxi formation was changed by the marine facies completely in the Mizhi- Zizhou and Tawan- Gaoqiao area. It has more advantages in lithologic characteristics, sand thickness and reservoir performance,which are favorable for gas exploration.
出处
《科技导报》
CAS
CSCD
北大核心
2016年第2期110-115,共6页
Science & Technology Review
关键词
沉积环境
砂体展布
山2段
鄂尔多斯盆地
sedimentary environments
sand-body distribution
member 2 of Shanxi formation
Ordos Basin
