引用本文:
【打印本页】   【下载PDF全文】   查看/发表评论  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览次   下载 本文二维码信息
码上扫一扫!
分享到: 微信 更多
A wellbore flow model and coupling solution for supercritical CO2 fracturing
LI Xiaojiang, LI Gensheng, WANG Haizhu, TIAN Shouceng, SONG Xianzhi, LU Peiqing, LIU Qingling1,2
1. State Key Laboratory of Petroleum Resource and Prospecting in China University of Petroleum, Beijing 102249, China;2. Research Institute of Petroleum Engineering, SINOPEC, Beijing 100101, China
Abstract:
Supercritical carbon dioxide (CO2) can be applied as a new type of non-aqueous fracturing fluid. Precise prediction of the bottomhole temperature and pressure is the key requirement for the design and operation of supercritical CO2 fracturing. In this paper, a theoretical CO2 wellbore flow model was developed based on the conservation laws of mass, momentum and energy balance. The equation of state for CO2 proposed by Span and Wagner and a model proposed by Fenghour et al. were adopted to calculate the in-situ thermodynamic and transport properties of CO2 at wellbore conditions. The model was solved by coupling pressure and temperature along the wellbore and coupling tubing-annulus-formation in the radial direction. The derivation of the model was validated by comparing with the classical models, and the accuracy of model was verified using data from a CO2 injection well, in which the relative errors are below 1%. The results indicate that heat generated by gas expansion or compression should be considered in the process of CO2 injection at a low rate. Moreover, the heat generated by gas expansion and friction should be considered for the CO2 fracturing at high injection rates, while the Joule-Thompson effect can be neglected at most operating conditions.
Key words:  supercritical CO2  fracturing  wellbore flow model  coupling solution  heat source/sink