Abonnement à la biblothèque: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

PHASE PREDICTION AND CONTROL METHOD OF SUPERCRITICAL CARBON DIOXIDE FLUID IN FRACTURING OIL WELLBORE

Get access (open in a dialog) DOI: 10.1615/IHTC16.cms.024219
pages 1851-1858

Résumé

The low permeability oil and gas reservoirs are abundant in China, and the hydraulic fracturing technology is widely employed for exploiting this kind of energy resources. Whereas, the hydraulic fracturing technology encounters various technical issues due to the used fluid contains liquid phase during the fracturing process, which results in the clay expansion, the water lock damage and the low backflow rate. The supercritical carbon dioxide (S-CO2) fracturing technology may provide an alternative method, the adopted fluid (i.e., S-CO2) without liquid phase which contribute to avoid the aforementioned problems. Nevertheless, the phase change of CO2 during fracturing is very complicate, and it is difficult to accurately predict and control the CO2 phase transition. In this work, an evaluation model was developed for analyzing the physical properties of the S-CO2. Additionally, based on a specific oil field, the temperature and pressure distribution of wellbore during the S-CO2 fracturing process were investigated. The results indicate that the CO2 in oil tubing below 2300 m always maintain at the supercritical state. The temperature of the bottom hole CO2 is reduced to 50°C from 100°C when the geothermal gradient is 25°C/km, meanwhile, the higher geothermal gradient results in greater temperature decreases. Through the analysis of the flow and heat transfer of S-CO2 in the wellbore, the phase state of the S-CO2 can be well predicted, and there is possibility that it will contribute to improve the performance of exploring the low permeability oil and gas reservoirs.