裂缝内CO2压裂液相态分布特征的数值模拟研究
Numerical Simulation Study on the Phase Distribution Characteristics of CO2 Fracturing Fluid inside Cracks
徐智颢 1杜博 1李东东1
作者信息
- 1. 陕西省煤层气开发利用有限公司,西安 710000
- 折叠
摘要
CO2 干法压裂工艺利用纯液态CO2 进行携砂压裂施工,对储层进行改造,该技术已实现大量现场应用.但是,CO2 压裂液在裂缝内的相态分布尚未进行系统的研究.运用流体模拟软件,建立二维裂缝的物理模型,分析CO2 压裂液在造缝过程中的相态分布.研究结果表明,在造缝过程中,CO2 压裂液以液态CO2 和超临界CO2 两种相态存在,并且以超临界CO2 的分布为主;CO2 压裂液充满裂缝时,随着测点与井口距离的增加,CO2 温度先增加,然后趋于稳定;CO2 压裂液进入裂缝内,压裂施工完成 20 min时,裂缝内CO2的温度达到地层温度;地层温度越低,液态CO2 吸热越慢,达到超临界相态所需时间越长,超临界CO2 分布区距离缝口越远.
Abstract
The CO2 dry fracturing technology utilizes pure liquid CO2 for sand carrying fracturing construction,and transforms the reservoir,this technology has been widely applied on site.However,the phase distribution of CO2 fracturing fluid within fractures has not been systematically studied.The physical model of two-dimensional fractures is established by using fluid simulation software to analyze the phase distribution of CO2 fracturing fluid during the fracturing process.The research results indicate that during the fracturing process,CO2 fracturing fluid exists in two phases of liquid CO2 and supercritical CO2,and the distribution of supercritical CO2 is the main one;when CO2 fracturing fluid is filled with cracks,as the distance between the measuring point and the wellhead increases,the CO2 temperature first increases and then tends to stabilize;CO2 fracturing fluid enters the crack,and when the fracturing construction is completed for 20 min,the temperature of CO2 in the crack reaches the formation temperature;the lower the formation temperature,the slower the heat absorption of liquid CO2,the longer it takes to reach the supercritical phase,and the farther the distribution area of supercritical CO2 is from the fracture.
关键词
裂缝/CO2/压裂液/相态/分布特征/数值模拟/液态CO2/超临界CO2/干法压裂Key words
cracks/CO2 fracturing fluid/phase/distribution characteristics/numerical simulation/liquid CO2/supercritical CO2/dry fracturing引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据