中国石油大学学报（自然科学版）2018，Vol.42Issue(2)：87-94,8.DOI:10.3969/j.issn.1673-5005.2018.02.010
超临界CO2压裂井筒流动模型及耦合求解
A wellbore flow model and coupling solution for supercritical CO2fracturing
摘要
Abstract
Supercritical carbon dioxide (CO2) can be applied as a new type of non-aqueous fracturing fluid. Precise predic-tion of the bottomhole temperature and pressure is the key requirement for the design and operation of supercritical CO2frac-turing. In this paper,a theoretical CO2wellbore flow model was developed based on the conservation laws of mass,momen-tum and energy balance. The equation of state for CO2proposed by Span and Wagner and a model proposed by Fenghour et al. were adopted to calculate the in-situ thermodynamic and transport properties of CO2at wellbore conditions. The model was solved by coupling pressure and temperature along the wellbore and coupling tubing-annulus-formation in the radial direc-tion. The derivation of the model was validated by comparing with the classical models,and the accuracy of model was veri-fied using data from a CO2injection 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 CO2injection at a low rate. Moreover,the heat gener-ated by gas expansion and friction should be considered for the CO2fracturing at high injection rates,while the Joule-Thomp-son effect can be neglected at most operating conditions.关键词
超临界CO2/压裂/井筒流动模型/耦合求解/热量源汇Key words
supercritical CO2/fracturing/wellbore flow model/coupling solution/heat source/sink分类
能源科技引用本文复制引用
李小江,李根生,王海柱,田守嶒,宋先知,陆沛青,刘庆岭..超临界CO2压裂井筒流动模型及耦合求解[J].中国石油大学学报（自然科学版）,2018,42(2):87-94,8.基金项目
国家自然科学基金项目(U1562212) （U1562212）
国家"973"重点基础研究发展规划项目(2014CB239203) （2014CB239203）
