低熟页岩电加热原位改质油气资源潜力数值模拟——以松辽盆地南部中央坳陷区嫩江组一、二段为例

Prediction of low-maturity shale oil produced by in situ conversion: a case study of the first and second members of Nenjiang Formation in the Central Depression, southern Songliao Basin, Northeast China

柳波 刘阳 刘岩 贺君玲 高逸飞 王浩力 范晶 付晓飞

LIU Bo LIU Yang LIU Yan HE Junling GAO Yifei WANG Haoli FAN Jing FU Xiaofei

东北石油大学“陆相页岩油气成藏及高效开发”教育部重点实验室, 黑龙江 大庆 163318 长江大学 录井技术与工程研究院, 湖北 荆州 434023 中国石油 吉林油田分公司, 吉林 松原 138000 中国石油 大庆油田分公司, 黑龙江 大庆 163000

Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development, Ministry of Education, Northeast Petroleum University, Daqing, Heilongjiang 163318, China Institute of Mud Logging Technology and Engineering, Yangtze University, Jingzhou, Hubei 434023, China PetroChina Jilin Oilfield Company, Songyuan, Jilin 138000, China PetroChina Daqing Oilfield Company, Daqing, Heilongjiang 163000, China

松辽盆地中央坳陷上白垩统嫩江组是一套分布面积广、厚度大、富含有机质的低熟页岩层系。根据测井资料和岩心实测数据，研究页岩有机质丰度和类型的空间非均质性，据此建立地质模型，并基于生烃动力学和热传导模型，对研究区电加热原位改质资源潜力进行预测。嫩江组各段总体上处于未成熟—低成熟阶段，是以生油为主的烃源岩。嫩江组一、二段古水体为淡水—微咸水，生烃母质主要为藻类体，有机质类型以Ⅱ1—Ⅱ2型干酪根为主，其中嫩一段烃源岩综合品质最好，优质烃源岩主要分布在长岭凹陷新北—大安地区。通过原位电加热模拟可以推断，2 kW加热功率下，页岩温度上升迅速，在加热4年后温度可达到600℃以上；1 kW加热功率下，则需要约8年。有机质转化率在加热到第五年时已经接近100%，达到原位改质最大资源丰度；加热至第五年末，在2 kW功率下，嫩一段页岩可产生的页岩油资源量为245.02×108 t，嫩二段为65.89×108 t。

The Nenjiang Formation in the Centrel Depression of the Songliao Basin consists of organic-rich low-maturity shale with a wide distribution and large thickness. In this study, the spatial heterogeneity of organic matter (OM) abundance and types was studied based on core measurements and log data. A geological model was used to predict the potential of in situ electric heating using hydrocarbon generation kinetics and heat conduction models. All members of the Nenjiang Formation are in the immature to low-maturity stage and oil-prone. The first and second members of the Nenjiang Formation (K2n1+2) contain mainly types Ⅱ1 and Ⅱ2 kerogen with alginite the dominant maceral. The shale of K2n1 has the best generation quality, and the high-quality source rocks within this member are mainly distributed in the Xinbei-Daan area of the Changling Sag. It can be inferred from the in situ electric heating simulation that the temperature rises rapidly, and reaches above 600 ℃ after 4 years of heating at 2 kW heating power. At 1 kW of heating power, it would take about 8 years. As the organic matter conversion rate approached 100% by the fifth year of heating, the maximum resource abundance was achieved. At the 2 kW heating power, the resource of the K2n1 reaches 24.5×109 t at the end of the fifth year, and 6.6×109 t of the K2n2.

国家自然科学基金“陆相页岩油储层孔隙结构非均质性成因及其对烃类赋存相态的影响” 41972156

https://doi.org/10.11781/sysydz202004533