压裂-注氮原位裂解油页岩加热工艺及传热模拟

提出了一种油页岩地下原位转化的新方法,即压裂-注氮原位裂解油页岩技术.油页岩储层压裂后,在加热井内下入电加热器,然后向井内注入氮气,利用加热后的高温氮气原位裂解油页岩.介绍了该方法与传统的电加热法和对流加热法相比的优势,以及特别适用的地层,并且对加热氮气过程进行了传热模拟,优化了气体加热器的参数,确定加热器的最佳长度为30 m,其热流密度为11 k W/m2.针对本工艺方法特别适用的薄层油页岩地下原位开采,进行了地层加热时间的传热模拟,确定了80 d即可将井距15 m,矿层1.5 m厚的油页岩加热到裂解温度,较电加热法和对流加热法的加热时间明显缩短.

Heating Technology and Heat Transfer Simulation for Oil Shale of In-situ Pyrolysis by Fracturing and Nitrogen Injection

A new method for the in-situ conversion of oil shale was introduced i.e.， oil shale in-situ pyrolysis technique by fracturing and nitrogen injection. Electrical heater was put into the heating well and nitrogen was then pumped into the well. As a result， the oil shale layer was pyrolyzed by heated nitrogen. The advantages of the proposed method and the suitable layers were also introduced in comparison with traditional electrical heating and convective heating， and a computer simulation was done for the heating process of nitrogen. The parameters of the heater were optimized and it was confirmed that the length of the electrical heater was 30m and the heat flux was 11kW/m2. Finally， based on the suitable thin oil shale layers， it was verified by the computer simulation that the heating time is 80days under the condition that the distance of the heating well and the production well is 15m while the thickness of the oil shale layer is 1.5m. Obviously， the time is shortened compared with traditional electrical heating or convective heating.