东海盆地西湖凹陷烃源岩成熟度厘定——FAMM分析的证据

Maturity determination of hydrocarbon source rocks in Xihu Sag: Evidence from fluorescence alteration of multiple macerals

张隽

Zhang Jun

中国石化 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

镜质体反射率是评价烃源岩有机质成熟度的主要指标之一，已有研究表明，镜质体反射率（Ro）除受控于有机质热演化程度外，还受烃源岩有机质类型等因素的影响，镜质体富氢程度制约镜质体反射率的抑制程度，影响了Ro测值的准确性。多组分荧光变化（FAMM）技术可有效解决镜质体反射率的抑制问题。利用FAMM技术和镜质体反射率分析方法，对取自东海盆地西湖凹陷9口钻井的10件平湖组烃源岩样品进行了成熟度分析，结果显示样品的镜质体反射率存在不同程度的抑制，抑制校正值介于0.01%~0.25%，个别样品稍有增强现象。根据FAMM分析结果，以TWT1井为例，厘定了该井区平湖组烃源岩的成熟度，认为TWT1井区平湖组烃源岩的现今成熟度应处于0.90%~1.41%，而不是实测镜质体反射率分析结果显示的0.77%~1.21%。研究结果有助于合理评价平湖组烃源岩生烃潜力及油气资源潜力。

Vitrinite reflectance is one of the main indexes to determine the thermal maturity of hydrocarbon source rocks. Previous results indicated that vitrinite reflectance (Ro) is not only controlled by thermal maturity, but also affected by the type of organic matter of source rock. The hydrogen content of vitrinite controls the level of vitrinite reflectance suppression and influences Ro accuracy. The fluorescence alteration of multiple macerals (FAMM) can solve vitrinite reflectance suppression effectively. The thermal maturity of 10 source rock samples from the Pinghu Formation in the Xihu Sag of East China Sea Basin were analyzed by means of FAMM and vitrinite reflectance. Results showed that the vitrinite reflectance of hydrocarbon source rocks from the Pinghu Formation were suppressed to some degree and the suppression corrected value varies from 0.01% to 0.25%. For well TWT1 the present thermal maturity of source rocks from the Pinghu Formation was determined as 0.90%-1.41%Ro by FAMM, but 0.77%-1.21%Ro by vitrinite reflectance analyses. The study helps evaluate hydrocarbon potential in the Pinghu Formation.

国家科技重大专项“大型油气田及煤层气开发”（2011ZX05002-003）资助。

https://doi.org/10.11781/sysydz201703417