源储一体烃源岩精确评价——以准噶尔盆地吉木萨尔凹陷芦草沟组为例

Accurate evaluation of source rocks in source-reservoir integration: a case study of source rocks in Lucaogou Formation, Jimsar Sag, Junggar Basin

李二庭 王剑 李际 何丹 高秀伟 刘翠敏 王海静

LI Erting WANG Jian LI Ji HE Dan GAO Xiuwei LIU Cuimin WANG Haijing

新疆砾岩油藏实验室, 新疆 克拉玛依 834000 中国石油 新疆油田分公司 实验检测研究院, 新疆 克拉玛依 834000

Xinjiang Laboratory of Petroleum Reserve in Conglomerate, Karamay, Xinjiang 834000, China Research Institute of Experiment and Testing, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China

准噶尔盆地吉木萨尔凹陷中二叠统芦草沟组源储一体，岩心样品中常见原油浸染现象，导致烃源岩评价参数测定不准。针对这种现象，利用氯仿抽提技术，分析了运移烃类对烃源岩评价结果的影响，细分岩性准确评价了该区芦草沟组源储一体烃源岩的生烃潜力。结果显示：（1）烃源岩中可溶有机质烃类含量越高，会导致烃源岩有机碳测定值偏差越高，热解参数S1、S2值增大，Tmax值降低，氢指数增大，对于源储一体烃源岩应先进行氯仿抽提，再进行热解分析。（2）吉木萨尔凹陷芦草沟组烃源岩以泥岩类有机质丰度最高，属于好—最好的生油岩，其次为白云岩类，属于好的生油岩，灰岩属于中等—好的生油岩，粉砂岩类主要为差生油岩；烃源岩有机质类型以Ⅰ型、Ⅱ1型、Ⅱ2为主，少量Ⅲ型，整体达到成熟大量生油阶段。抽提后的烃源岩有机碳含量、氢指数及Tmax值，可有效用于源储一体烃源岩及油浸烃源岩的准确评价。

In the Middle Permian Lucaogou Formation in the Jimsar Sag of Junggar Basin, source rocks and reservoirs are integrated. Crude oil impregnation is very common in core samples, which leads to the inaccurate determination of source rock evaluation parameters. The impact of migrated hydrocarbon on source rock evaluation was analyzed using chloroform extraction. The hydrocarbon potential of source rocks which were integrated with reservoirs in the Lucaogou Formation was evaluated accurately in view of different lithologies. The higher the content of soluble hydrocarbons in the source rock, the higher the deviation of the measured value of the source rock's total organic carbon, the higher the pyrolysis parameters S1 and S2, the lower the Tmax value, and the higher the hydrogen index. For source rocks integrated with reservoirs, chloroform extraction should be performed first, followed by pyrolysis analysis. For the Lucaogou source rocks in the study area, mudstones have the highest abundance of organic matter and comprise the best source rocks, followed by dolomites, which are good source rocks. Limestones are medium-good source rocks, while siltstones are mainly poor source rocks. The organic matter types of source rocks are mainly type Ⅰ, type Ⅱ1, and type Ⅱ2, with a small amount of type Ⅲ, which has reached the mature oil production stage. The organic carbon content, hydrogen index, and Tmax value of extracted source rocks can be effectively used for the accurate evaluation of the source rocks integrated with reservoirs or impregnated with oil.

新疆维吾尔自治区岩页油重点实验室开放课题 2017D04023

https://doi.org/10.11781/sysydz202102335