摘要
为了准确确定断裂的封闭性,在对断层岩形成过程及封闭性演化特征进行研究的基础上,根据断层岩开始压实成岩时间和封闭能力形成时间把断层岩封闭性演化划分为3个阶段:(1)压实不封闭阶段,时间从断裂停止活动至断层岩开始压实成岩;(2)成岩弱封闭阶段,时间从断层岩开始压实成岩至封闭能力形成;(3)成岩强封闭阶段,时间从断层岩封闭能力形成至现今。由此建立了一套断层岩封闭性演化阶段的确定方法,并将其应用于渤海湾盆地南堡凹陷南堡5号构造,以确定该构造内的f_1、f_2、f_3这3条断裂在古近系东营组三段(以下简称东三段)断层岩中的封闭性演化阶段。结果表明:(1)f_1断裂在东三段断层岩封闭性演化目前处于第1封闭性演化阶段,即压实不封闭阶段,不利于油气的聚集与保存;(2)f_2、f_3断裂在东三段断层岩封闭性演化目前均处于第3封闭性演化阶段,即成岩强封闭阶段,有利于油气的聚集与保存。结论认为:该方法确定的结果与目前该构造f_1、f_2、f_3断裂两侧东三段已发现的油气分布规律相吻合,表明采用该方法来确定断层岩封闭性演化阶段是可行的。
In order to accurately define the sealing capacity of faults, based on the study of the formation process of fault rocks and their sealing capacity evolution characteristics it is necessary to divide this process into 3 stages according to their initial compaction diagen- esis time and sealing capacity formation time. The first stage lasts from the termination of faulting activity to the initial compaction dia- genesis of fault rocks. And in this stage, it is compaction without sealing. The second stage lasts from the initial compaction diagenesis of fault rocks to the formation time of sealing capacity, and it is characterized by diagenesis and weak sealing capacity. And the third stage has lasted since the formation time of sealing capacity of fault rocks, and it is characterized by diagenesis and strong sealing capacity. And accordingly, a method for determining the sealing capacity evolution stage of fault rocks was developed. This method was applied to No.5 structure of the Nanpu Sag in the Bohai Bay Basin to determine the sealing capacity evolution stage of Faults ft, f2 and f3 in Ed3 fault rocks. It is shown that the sealing capacity evolution of Fault fl in the Ed3 fault rocks is currently in its first stage, namely, the compaction without a sealing capacity, which is not conducive to accumulation and preservation of oil and gas; and the sealing capacity evolution of Faults f2 and f3 in the Ed3 fault rocks is currently in their third phases, namely, the diagenesis with a strong sealing capacity, which is conducive to accumulation and preservation of oil and gas. It is concluded that the result confirmed by this method is consistent with the discovered distribution rules of Ed3 oil and gas on both sides of Faults fl, f2 and f3 in No.5 structure. It is indicated that this method is fea- sible to determine the sealing capacity evolution stage of fault rocks.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2017年第10期11-16,共6页
Natural Gas Industry
基金
国家自然科学基金项目"油源断裂转换带优势输导油气条件研究"(编号:41372153)
关键词
渤海湾盆地
南堡凹陷
古近纪
断层岩
封闭性
演化阶段
确定方法
压实成岩时间
封闭能力形成时间
Bohai Bay Basin
Nanpu Sag
Paleogene
Fault rock
Sealing property
Evolution stage
Determination method
Compaction diagenesis time
Timing of sealing capacity
