摘要
以地震、测井、录井及地球化学资料为基础,本文采用Easy-Ro方法对渤海湾盆地青东凹陷进行了古地温反演,计算了该地区的古地温梯度,并进一步利用人工取井和盆地模拟方法,确定了沙四上亚段和沙三下亚段烃源岩的成熟度和展布特征,预测了有利生烃区带的分布。结果表明,青东地区的古地温梯度为3.8℃/100m;沙四上亚段烃源岩的成熟度较高,进入成熟-高成熟阶段;沙三下亚段的烃源岩成熟度相对较小,为成熟-低成熟阶段;纵向上,沙四上亚段较沙三上亚段生烃范围大、烃源岩成熟度高;横向上,主要的生烃区带集中在青东凹陷主体洼陷地区(北部断阶带、北次洼、南次洼、中次洼)以及青南洼陷,青东凹陷西斜坡地区未进入生烃门限。
Based on seismic, logging and geochemical data, the Easy-Ro model was adopted to invert the paleogeothermal history of the Qingdong sag, and to calculate the paleogeothermal gradient. Based on data of artificial wells and thickness of the hydrocarbon source rocks, the maturity and distribution of the upper 4th member and the lower 3th member of the Shahejie Formation were discussed and the potential hydrocarbon generation zone was predicted. The results showed that the paleogeothermal gradient of the Qingdong Sag was 3.8℃/100m, the maturity of source rocks in the upper 4th member of the Shahejie Formation was higher than that of the lower 3th member of the Shahejie Formation which are in the stages of matureover mature and mature-low mature, respectively. In a vertical plane, the hydrocarbon generation domain and maturity of source rocks of the 4th upper 4th member of the Shahejie Formation was larger than those of the lower 3th member of the Shahejie Formation,while in a plane, the main hydrocarbon zone are located on the main part of the Qingdong Sag （North fault-step, north sub-sag, middle sub-sag and south sub-sag） and the Qingnan subsag. The western slope of the Qingdong Sag did not reach the hydrocarbon generating threshold.
出处
《高校地质学报》
CAS
CSCD
北大核心
2013年第1期141-147,共7页
Geological Journal of China Universities
基金
教育部高等学校博士学科点新教师基金(K0901045A)
中央高校基本科研业务费专项资金(27R1101053A)联合资助
关键词
青东凹陷
烃源岩
镜质体反射率
古地温梯度
热演化史
Qingdong sag
source rocks
vitrinite reflectance
geothermal gradient
thermal history
