辽西拗陷凌源地区洪水庄组烃源岩石油地质特征及生烃潜力

THE SOURCE ROCKS OF HONGSHUIZHUANG FORMATION IN LINGYUAN AREA OF LIAOXI DEPRESSION:Petroleum Geology and Hydrocarbon Generation Potential

洪水庄组页岩是燕辽裂陷带的主力烃源岩层,具有较好的生烃潜力,而辽西拗陷的洪水庄组研究相对薄弱,对烃源岩发育特征和生烃潜力等问题研究不够深入,制约了该区中—新元古界油气地质条件研究和勘探部署工作.为揭示辽西拗陷洪水庄组烃源岩生烃潜力和油气保存条件,以辽西拗陷凌源地区辽凌地2井和3条剖面的洪水庄组样品为对象,进行了烃源岩地球化学特征分析研究.结果表明:辽西拗陷凌源地区中元古界洪水庄组烃源岩有机质丰度较高,具有较好的生烃物质基础;有机质类型主要为Ⅰ—Ⅱ1型,局部含Ⅱ2和Ⅲ型;等效镜质体反射率Ro分布在1.15%~2.26%,处于成熟—高成熟阶段,部分样品过成熟,综合评价为中到好烃源岩,生烃潜力较好.凌源地区以洪水庄组为生油层,可构成2套完整的生储盖组合,且处于有利储集相带,显示出良好的油气勘探前景.

The shale of Hongshuizhuang Formation is the dominant source rock of Yanliao rift belt with good hydrocarbon generation potential. However, the study of Hongshuizhuang Formation in Liaoxi Depression is relatively weak, which restricts the study of Meso-Neoproterozoic oil-gas geological conditions and exploration in this area. To reveal the hydrocarbon generation potential and oil-gas preservation conditions of source rocks in the area, geochemical analysis is carried out for samples from LLD2 well and 3 sections in Lingyuan area. The results show that the source rocks of Mesoproterozoic Hongshuizhuang Formation generally have high organic abundance and good hydrocarbongenerating material basis. The organic matter is mainly I-II1type, partly II2and III types. The Rodistribution ranges from1.15% to 2.26%, belonging to mature-high mature stage, and some samples are over-mature, which are comprehensively evaluated as medium-good source rocks with good hydrocarbon generation potential. The Hongshuizhuang Formation in Lingyuan area serves as source bed located in favorable reservoir facies belt and can compose two sets of complete source-reservoir-cap assemblages, showing good oil-gas exploration prospects.