Dear Editors,Exploitation of low permeability oilfield has become an interest of the world due to the decline of conventional oil reserves.Flooding has been observed to be able to enhance oil recovery in tight sandstone reservoir.The pore throat diameter of the sandstone described above is in nano/micro scale,and remaining oil and irreducible water exist simultaneously.Therefore,better understanding of reservoir behavior is essential to predict future performance of
Ri Ma BaoXin Yang MiaoCheng Jing FengYing Zhi ZhangHong Lei ZhanKun ZhaoMao Rong WangJian Quan Yao
The goal of continuous ambient participate monitoring has been accomplished by the use of terahertz(THz)wave.The frequency-dependent spectrum and absorbance of the particulate matter(PM2.5)were measured in the range of 0–10 THz.The PM2.5 concentration was calculated according to the sampling time and air flow.With the increase of,the THz wave amplitude gradually decreased and the absorbance A of PM2.5 increased.The relationship between and A can be described mathematically through A0.5.Our results demonstrate that the terahertz wave could be a valuable tool to monitor and inspect the PM2.5 concentration.
LI QianZHAO KunZHANG Lei WeiLIANG ChuanZHANG Zhen WeiZHANG Cun LinHAN Dong Hai
The hydrous thermo-simulation experiments on oil shale sample from Liushuhe basin have been performed using autoclave.The mechanism and kinetics of oil shale pyrolysis were investigated.The formation mechanism of pyrolysates including retorting gas,oil and bitumen,were evaluated in the presence of saturated and unsaturated water,respectively.The results show that the physicochemical properties of water have greatly changed in high temperature and pressure.At the same time,water has three kinds of effect on the oil shale pyrolysis,including the protection of free radical,catalytic action and swelling.The pyrolysis temperature was carried out about 70C earlier,and the generated processing of hydrocarbon would be easier under the aqueous.The consecutive first order reaction model involving bitumen as an intermediate product was used in the data analysis in order to determine the pyrolysis kinetic parameters.It was found that the apparent activation energy of kerogen pyrolysis was lower than bitumen pyrolysis.
Terahertz time-domain spectroscopy(THz-TDS)was used for the quantitative detection of sulfur content in gasoline.Models of chemo metrics methods and partial least squares(PLS)were built to measure THz-TDS and the sulfur content.All of the samples were divided into two parts.One part was used for calibration and the other one for validation.In order to evaluate the quality of the models,the correlation coefficient(R)and root-mean-square errors(RMSE)of calibration and validation models were calculated.The value of R and RMSE were close to 1 and 0 within acceptable levels,respectively,indicating that the combination of THz-TDS and PLS is a potential method for further quantitative detection.
QIN FangLiLI QianZHAN HongLeiJIN WuJunLIU HongLanZHAO Kun
