矿业科学学报2025，Vol.10Issue(6)：1042-1054,13.DOI:10.19606/j.cnki.jmst.2025097
变温压条件下深部煤岩孔-裂隙结构的超声波传播特征研究
Ultrasonic wave propagation characteristics in pore-fracture structure of deep coal under coupled thermo-pressure conditions
摘要
Abstract
The elasticity and physical properties of coal and rock,along with their variation characteris-tics,underpin the prediction of coalbed methane reservoirs and delineating"sweet spots".Physical properties are significantly influenced by temperature and pressure.This study aims to address the un-clear dynamic response mechanism of pore-fracture structures in deep coalbed methane reservoirs under coupled in-situ temperature and pressure conditions,coal and rock samples were taken from the Linxing Block in the Ordos Basin.Variable temperature and pressure ultrasonic pulse transmission tests(0～30 MPa,11～99 ℃)were conducted to analyze the response patterns of wave velocity and waveform char-acteristics to pore-fracture evolution.An improved dual-pore model was employed to quantify the tem-perature-pressure coupling constraint mechanism,establishing a nonlinear mapping relationship be-tween waveform similarity coefficient and porosity.Results indicate:Waveforms exhibited significantly higher sensitivity to confining pressure than wave velocity.When confining pressure increased from 0 to 30 MPa,both P-and S-wave shape similarity coefficients changed by over 60%,representing a 2.96-fold～5.99-fold increase relative to wave velocity.As confining pressure increased,coal-rock pore clo-sure primarily resulted from the synergy effects of rigid pore linear compression and flexible pore expo-nential closure.Temperature elevation(62℃,19 MPa)increased the total porosity of coal samples by 0.55%compared to 11℃,19 MPa conditions through thermal expansion effects.We obtained experi-mentally the waveform similarity coefficient-porosity mapping model(R2=0.786)and porosity inver-sion constraints(waveform,dual-pore,temperature-pressure),subsequently establishing a dynamic temperature-pressure,dual-pore fracture model for multi-parameter prediction of coalbed methane"sweet spots".These findings provide theoretical references for refined characterization and efficient development of coalbed methane reservoir properties.关键词
超声波传播特性/孔-裂隙结构/弹性模量/温压耦合/深部煤层气Key words
ultrasonic wave propagation characteristics/pore-fracture structure/elastic modulus/ther-mo-pressure coupling/deep coalbed methane分类
矿业与冶金引用本文复制引用
华明安,邹冠贵,刘燕海,刘家乐,刘铮航..变温压条件下深部煤岩孔-裂隙结构的超声波传播特征研究[J].矿业科学学报,2025,10(6):1042-1054,13.基金项目
国家自然科学基金(42274165) （42274165）
国家重点研发计划(2023YFB3211002) （2023YFB3211002）
