梨树断陷主力烃源岩判定及其地球化学特征

Identification of chief hydrocarbon source rocks in Lishu Fault Depression and their geochemical characteristics

宋振响 周卓明

Song Zhenxiang Zhou Zhuoming

中国石油化工股份有限公司 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China

通过对梨树断陷4套潜在烃源岩生烃潜力特征分析,确定了沙河子组为其主力烃源层,其次为营城组,火石岭组和登娄库组仅在局部地区发育有效烃源岩。采用20余项变量对梨树断陷有机碳含量大于0.5%的烃源岩进行聚类分析,结果表明梨树断陷有效烃源岩可以划分为4类,4类烃源岩的沉积环境、生烃潜力、母质来源及成熟度方面均存在一定的差异,以C类和D类源岩生烃潜力最高,与原油的可比性较好。从平面分布来看,C类源岩主要分布在四五家子、皮家及桑树台深洼深湖相沉积区域;A、B、D类源岩主要分布在苏家屯、双龙次洼及盆地边缘太平庄、七棵树、秦家屯等地区浅湖—半深湖及三角洲平原上的沼泽相沉积区域。

Based on the hydrocarbon generation potential of 4 sets of source rocks developed in the Lishu Fault Depression, the results illustrated that the chief hydrocarbon source layer is K1sh and the secondary layer is K1yc; meanwhile, the effective source rocks of K1h and K1d formations only developed in some certain areas. We made a cluster analysis to source rock samples (TOC>0.5%) based on more than 20 variables, and the results have shown that the source rock samples can be divided into 4 types and the geochemical characteristics of 4 types of source rocks are different in many respects, such as sedimentary environment, hydrocarbon generation potential, origin of organic matters and maturity stages. Type C and D source rocks have the highest hydrocarbon generation potential and they have good comparability with crude oils. Taking into account the plane distribution of source rocks, type C source rocks mainly distribute in Siwujiazi, Pijia and Sangshutai deep depressions with deep lake facies. Meanwhile, type A, B and D source rocks mainly distribute in Sujiatun sag, Shuanglong sag and Taipingzhuang, Qikeshu, Qinjiatun areas along the basin margins with shallow lake facies, semi-deep lake facies and swamp subfacies within delta plain sedimentary environment.

中国石油化工股份有限公司科技部项目(P09026)资助。

https://doi.org/10.11781/sysydz201304438