Oil geochemistry derived from the Qinjiatun–Qikeshu oilfields: insight from light hydrocarbons

• 作者: Jin Li Ting Kong Min Zhang
• 学科: 地球科学
• 关键词: Light hydrocarbons Crude oil Lishu Fault Depression Geochemistry characteristic
• 年，卷（期）: 2022,（3）
• 页码范围: 433-440
• 页数: 7页
• 语种: 英文
• DOI: 10.1007/s11631-017-0243-6

摘要

A suite of 27 oils from the Qinjiatun–Qikeshu oilfields in the Lishu Fault Depression of the Songliao Basin was analyzed using whole oil gas chromatography. In combination with the relative distribution of C27, C28, and C29 regular steranes, detailed geochemical analyses of light hydrocarbons in oil samples revealed crude oils characterized by the dual input of lower aquatic organisms and higher terrestrial plants. Several light hydrocarbon indicators suggest that the liquid hydrocarbons have maturities equivalent to vitrinite reflectances of around 0.78%–0.93%. This is consistent with the maturity deter mination of steranes C29 20S/(20S + 20R) and C29 ααβ/(ααα+αββ) . Crude oils derived from the two distinct oilfields likely both have source rocks deposited in a lacustrine environment based on light hydrocarbon parameters and on higher molecular weight hydrocarbon parameters. The results show that light hydrocarbon data in crude oils can provide important information for understanding the geochemical characteristics of the Qinjiatun–Qikeshu oils during geologic evolution.