摘要
古构造的高点通常是致密气长期运移和聚集的有利低势区,古构造恢复对致密砂岩气勘探尤为重要。以沁水盆地南部地区为例,基于该地区丰富的钻井、录井、测井等资料,对该地区在燕山早期(J_1—J_2)、燕山晚期(J_3—K_1)及喜马拉雅中期(E—N)等3个关键构造演化期的古构造进行了恢复。结果表明,自晚三叠世以来,本区表现为整体隆升剥蚀,强剥蚀区沿着NE—SW方向展布。燕山运动期间古隆起具有继承性,晚二叠世地层挤压变形强烈,古构造表现出"多隆多坳"特征;喜马拉雅运动中期出现"夷平化"现象,逐渐接近现今构造特征,部分古隆起逐渐变得宽缓,构造形态表现为"背斜宽缓,向斜紧闭"。将喜马拉雅运动中期的古构造单元划分为相对隆起带、相对斜坡带及相对坳陷带。相对隆起带是下一步该区煤系致密砂岩气勘探的有利区域。
The paleohighs are generally favorable accumulation areas for tight gas,so paleo-tectonic restoration is particularly important. Taking southern Qinshui Basin as an example,paleo-tectonic restoration was carried out for key tectonic stages of early Yanshanian（J_1-J_2）,late Yanshan（J_3-K_1）and middle Himalayan（E-N）periods based on drilling,log and logging data. The results show that the whole area has been uplifted and eroded since the Late Triassic,and the strong erosion area distributed along the NE-SW direction. During the period of Yanshan movement,the paleouplift was inherited,the Permian strata were deformed strongly,and the paleo-tecnonic shows＂multi-highs and multi-lows＂features. Deplanation occurs during the middle Himalaya movement,and the paleo-tecnonic is gradually close to the current feature. Some of the paleo uplifts gradually become wide and gentle,and their tectonic forms are characterized by wide anticline and closed syncline. The paleo-tectonic units during the middle period of Himalayan movement were divided into highs,ramp and lows. It is suggested that paleo highs should be exlpored for tight sandstone gas in coal measure.
出处
《岩性油气藏》
CSCD
北大核心
2017年第6期43-50,共8页
Lithologic Reservoirs
基金
国家自然科学基金"硬脆/塑性泥页岩微裂缝产生的岩石物理学机制基础研究"(编号:41572130)
国家"十三五"重大科技专项"四川盆地周缘海相页岩气有利区优选及重点目标评价"(编号:2017ZX05035001-007)联合资助
关键词
古构造恢复
致密砂岩气
油气意义
沁水盆地
paleo-tectonic restoration
tight sandstone gas
hydrocarbon significance
Qinshui Basin
