二氧化碳爆破储层改造近炮孔处岩石性质变化及温度分布规律研究  

Rock property change and temperature distribution near blasting holes in carbon dioxide blasting reservoir treatment

作　　者：郑君 樊涛 窦斌[1] 吴天予 ZHENG Jun;FAN Tao;DOU Bin;WU Tianyu(Faculty of Engineering,China University of Geosciences,Wuhan Hubei 430074,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《钻探工程》2022年第3期13-22,共10页Drilling Engineering

基　　金：国家重点研发计划“未固结砂岩热储层保护与增效钻完井技术及材料”(编号:2019YFB1504201)。

摘　　要：传统的地热井井身结构不适用于利用二氧化碳爆破技术进行干热岩储层建造,因此本文基于二氧化碳爆破致裂技术建造干热岩储层的新型井身结构工艺进行了进一步探究。结合该工艺水平井段(炮孔)钻进过程实际工况,对钻井后水平井段(炮孔)附近干热岩储层的物理力学性质变化规律及储层温度分布特征进行了岩石力学实验和数值模拟研究。研究结果表明钻井液降温产生的热应力作用是储层岩石性质发生变化、出现热损伤区的主要原因;冷却过程中炮孔附近储层呈现出“快速降温区-平缓降温区-未降温区”的区域性温度分布特征;储层初始温度和冷却时长对快速降温区温度分布以及热损伤区范围影响较大。本研究可以为二氧化碳爆破致裂干热岩储层建造提供理论指导。The traditional geothermal well structure is not suitable for carbon dioxide blasting technology to build hot dry rock reservoir;Thus,this paper further explores a new well structure and related technology suitable for carbon dioxide blasting technology.With regard to the actual drilling conditions in the horizontal well section(blasting hole)of the new well structure,rock mechanics experiments and thermal⁃fluid⁃solid three⁃field coupling numerical simulation were conducted to study the variation law of physical and mechanical properties and reservoir temperature distribution characteristics of hot dry rock reservoirs near horizontal well sections(blasting hole)after drilling.The results show that the thermal stress produced by cooling of drilling fluid is the main cause for the change of reservoir rock properties and occurrence of the thermal damage zone.The regional temperature distribution exhibits the characteristics of“rapid cooling zone⁃steady cooling zone⁃uncooling zone”in reservoir near the borehole during cooling.The initial reservoir temperature and the cooling time have major influence on temperature distribution in the rapid cooling zone and on the thermal damage zone.This study can provide more accurate theoretical guidance for carbon dioxide blasting fractured hot dry rock reservoir.

关 键 词：干热岩 二氧化碳爆破 储层改造 炮孔 热损伤 温度分布 

分 类 号：P634[天文地球—地质矿产勘探]