Numerical Simulation and Field Test study on Heat Injection Pipeline of Oil Shale In-Situ Pyrolysis

Abstract:

As an unconventional oil and gas resource, oil shale is expected to be a substitute for oil. At present, the underground oil shale insitu pyrolysis technology has better prospects due to its good product quality and environmentfriendly to surroundings. The pyrolysis temperature is the key factor of oil shale insitu pyrolysis, so it is of great importance to reduce the heat loss of the heat injection pipe. Therefore, the heat transfer characteristic of heat injection pipe column for insitu pyrolysis is studied by numerical simulation and field test. According to the heat transfer calculation, the heat preservation and injection pipe column is designed to be a steel pipe with outer diameter of 32mm, and the outer layer is wrapped with 24mm thick aerogel. The numerical analysis shows that the larger the N2 injection flow rate is, the shorter the time to reach the steady temperature at the heat pipe column injection outlet can be; when the N2 inlet temperature of the pipe column is 500°C, the outlet temperature can reach 400℃ a certain time after gas injection. Field experiments are carried out on heat injection pipe column in Nong’an oil shale insitu pyrolysis pilot test project, the heat preservation effect is obtained and the temperature at the well bottom reaches the designed value, shale oil is successfully mined.