大庆石油地质与开发2026，Vol.45Issue(2)：105-113,9.DOI:10.19597/J.ISSN.1000-3754.202501033
液氮压裂辅助气体吞吐提高页岩油采收率实验
Experiment of liquid nitrogen fracturing assisted gas huff-and-puff to enhance shale oil recovery
摘要
Abstract
In order to improve matrix fluid flow capability of shale reservoir and solve the problem of low depletion recovery,a new method of liquid nitrogen fracturing assisted gas huff-and-puff to enhance oil recovery is proposed.This method is used to carry out N2 and CO2 injection cyclic huff-and-puff experiment on the cores after liquid nitro-gen fracturing,and to study the influence of different gas injection media,gas injection pressure and gas injection methods on shale oil recovery.NMR T2 spectrum test is combined to clarify the characteristics of micro-pore struc-ture changes after liquid nitrogen fracturing assisted gas huff-and-puff.The results show that liquid nitrogen can sharply reduce the surface temperature of rock from 76.2℃to-170℃within 5 minutes,instantly forming thermal stress of about 303 MPa,and compressing rock with induced fractures formed.With same gas injection pressure af-ter liquid nitrogen fracturing,cumulative recovery of 3 rounds of 3 injection modes including CO2 huff-and-puff,N2 huff-and-puff and N2 huff-and-puff followed by CO2 huff-and-puff are 57.34%,27.35%and 50.17%,respectively.The 3rd injection mode not only reduces CO2 demand but also gives full play to displacement advantages of the 2 kinds of gas injection media.Core porosity increases from 6.74%to 12.04%,permeability increases from 0.024×10-3 μm2 to 6.242×10-3 μm2,and average pore size increases from 4.94 nm to 47.79 nm.The research provides new idea and method for efficient development of shale oil and gas.关键词
页岩/液氮/压裂/吞吐/裂缝/孔隙结构Key words
shale/liquid nitrogen/fracturing/production/fractures/pore structure分类
能源科技引用本文复制引用
齐宏鹏,梁凤鸣,邓宝康..液氮压裂辅助气体吞吐提高页岩油采收率实验[J].大庆石油地质与开发,2026,45(2):105-113,9.基金项目
国家科技重大专项"鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程"(2016ZX05050) （2016ZX05050）
国家自然科学基金项目"盐度响应型水包稠油乳状液的构建及其再多孔介质中的运移行为研究"(51804036). （51804036）
