Geological characteristics and main controlling factors of Permian lacustrine tight oil in the eastern part of the Junggar Basin

Junwei Zhao,Huaimin Xu,Cui He,Lin Li,Zhen Yi,Huijing Fang,Zhicheng Lei 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.2

The Junggar basin is rich in oil and gas resources, and recently, unconventional oil and gas reservoirs have become important targets. Significant amounts of oil and gas are located in Permian formations in the Shazhang–Dajing area, however, fewer studies have focused on unconventional oil and gas reservoirs, particularly on the factors controlling the distribution of unconventional reservoirs. In this study, a sequence stratigraphic framework of the study area was developed based on cores, well logs and seismic data. Source rock samples were analyzed, including tests of kerogen, vitrinite reflectance, chloroform bitumen, organic carbon and group composition. The physical properties and pore characteristics of reservoir samples were also analyzed using scanning electron microscope and high resolution electron microscope. The Permian Pingdiquan Formation comprises three thirdorder sequences in which individual sequence can be divided into a low-stand system tract (LST), a transgression system tract (TST), an early high-stand system tract (E-HST), and a late high-stand system tract (L-HST). Several source rock lithologies have high total organic carbon (TOC), and are matured, having excellent hydrocarbon generation potential. Clastic and dolomitic rocks are the main reservoirs, and nanometer-scale pores are the main reservoir space in the tight reservoirs. The distribution of tight oil is controlled by the sequence stratigraphy, palaeogeomorphic units, and sedimentary facies. The fine sediments, which were generally deposited near the initial flooding surface (FFS) and the maximum flooding surface (MFS), are favorable zones for tight oil. The distributions of the hydrocarbon source rocks are controlled by the depositional environment, depending on the palaeogeomorphic units; the deep depression in the Huoshaoshan area and the moderately-deep depression in the Shishugou area are two distinct hydrocarbon generating centers. The distribution of tight oil is clearly controlled by the sedimentary facies; the tight oil is mainly located in the fan delta front and lacustrine depositional environments. The distribution of tight oil in this area is summarized, and favorable areas of tight oil are proposed.

Prevalence and risk factors for incidental prostate cancer in patients after transurethral resection of the prostate with negative results on prostate biopsy: A retrospective study

Zhenlang Guo,Junwei He,Jun Pan,Lijuan Huang,Jiadong Cao,Zunguang Bai,Shusheng Wang,Songtao Xiang,Chiming Gu,Zhaohui Wang 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.2

Purpose: This study aimed to explore the prevalence and predictors of incidental prostate cancer (IPC) after transurethral resection of the prostate (TURP) with negative results on transperineal magnetic resonance imaging (MRI)/transrectal ultrasonography (TRUS) fusion prostate biopsy or TRUS-guided prostate biopsy. Materials and Methods: Data of 253 patients who underwent TURP with a preliminary diagnosis of benign prostatic hyperplasia (BPH) were evaluated. The prevalence of IPC was calculated. Univariate and multivariate logistic regression analyses were conducted to explore independent predictive factors of IPC. Results: A total of 253 patients were included. IPC was diagnosed in 12 patients (4.7%). The mean age of the patients and the mean prostate volume were 69.8±7.07 years and 89.3±49.29 mL, respectively. The prevalence of IPC was higher in the TRUS guided prostate biopsy group than in the transperineal MRI/TRUS fusion prostate biopsy group (11 of 203 [5.4%] vs. 1 of 50 [2.0%], p=0.47), but the difference was not statistically significant. Our results indicated that older age (≥70 y) (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.02–1.27; p=0.025) and smaller prostate volume (OR, 0.97; 95% CI, 0.938–0.998; p=0.039) were associated with an increased incidence of IPC after TURP. Conclusions: Our findings indicate that the prevalence of IPC may be higher among patients who undergo transrectal prostate biopsy before TURP than among those who undergo transperineal MRI/TRUS fusion prostate biopsy. Older age and smaller prostate volume were independent predictors of increasing the risk for IPC after TURP.

Weather Forecasting Using Ensemble of Spatial-Temporal Attention Network and Multi-Layer Perceptron

Yuanpeng Li,Junwei Lang,Lei Ji,Jiqin Zhong,Zaiwen Wang,Yang Guo,Sailing He 한국기상학회 2021 Asia-Pacific Journal of Atmospheric Sciences Vol.57 No.3

Weather forecasting is a challenging task, which is especially suited for artificial intelligence due to the large amount of data involved. This paper proposed an end-to-end hybrid regression model, called Ensemble of Spatial-Temporal Attention Network and Multi-Layer Perceptron (E-STAN-MLP), to forecast surface temperature, humidity, wind speed, and wind direction at 24 automatic weather stations in Beijing. Combining the data from historical observations with the data from the numerical weather prediction (NWP) system, our proposed model give better results than the NWP system or previously reported algorithms. Our E-STAN-MLP model consists of two parts. One is to use the spatial-temporal attention based recurrent neural network to model the time series of meteorological elements. The other is a simple but efficient multilayer perceptron architecture forecasts the regression value while ignoring time dependence. Results at each time stamp are integrated together using a step-wise fusion strategy. Moreover, we use a joint loss step integrating both the regression loss function and the classification loss function to simultaneously forecast the wind speed and direction. Experiments demonstrate that our proposed E-STAN-MLP model achieves state-of-the-art results in weather forecasting.

Prediction of exploration targets based on integrated analyses of source rock and simulated hydrocarbon migration direction: a case study from the gentle slope of Shulu Sag, Bohai Bay Basin, northern China

Changqing Ren,Fugui He,Xianzhi Gao,Dongsheng Wu,Wenli Yao,Jianzhang Tian,Huiping Guo,Yuanxin Huang,Li Wang,Han Feng,Junwei Li 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.6

The Shulu Sag which is a rifted sag with NNE trend is located in the south of Jizhong Depression, Bohai Bay Basin, northern China. The gentle slope and three troughs are situated in the west and east of the sag, respectively. Both of the lower part of Shasan Member (Es3x) and the lower part of Shayi Member (Es1x) act as source rocks in this sag. Researches on the type, quantity, quality and thermal maturity of the respective organic matter have been conducted using Rock-Eval pyrolysis data. Type II is the dominant kerogen in Es1x of all troughs. However, Type II1 and III is the dominant kerogen in Es3x of Middle-Southern and Northern trough, respectively. TOC (total organic carbon) and pyrolysis S2 (hydrocarbon) values suggest that the Es1x source rocks in Middle-Southern and Northern trough are fair to good and poor to fair generative potential of hydrocarbon, separately. The Es3x source rocks in Middle-Southern and Northern trough possess fair to excellent and poor to fair generative potential of hydrocarbon, individually. Tmax (pyrolysis temperature at maximum S2) values indicate that most of Es3x samples are thermally mature, but all Es1x samples are thermally immature. Under large scale condition, the hydrocarbon secondary migration in the upper part of Shasan Member (Es3s), Shaer Member (Es2) and the upper part of Shayi Member (Es1s) have been simulated using fluid potential model with Arcgis 9.3 software. The simulation results reveal the direction of hydrocarbon secondary migration and the distribution of hydrocarbon migration-accumulation units (HMAUS), and also suggest that the hydrocarbon migration direction is obviously controlled by nose-like structure belts where most of hydrocarbons accumulate. That shows high reliability because they are consistent with the hydrocarbon exploration result in this area. On the basis of integrated analyses of source rocks and hydrocarbon migration direction, the following five areas in the gentle slope are identified to be the preferred hydrocarbon accumulation area: Taijiazhuang area, northern and southern Xicaogu area, as well as northern and southern Leijiazhuang area. It is considerably helpful to reduce the risk in hydrocarbon exploration of Shulu Sag.

NANOSCALE POROUS SILICON MICROCAVITY BIOSENSOR FOR NOVEL LABEL-FREE TUBERCULOSIS ANTIGEN–ANTIBODY DETECTION

BAO WU,GUOGUANG RONG,JUNWEI ZHAO,SHULIN ZHANG,YONGXIN ZHU,BOYONG HE 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.6

One third of the world population is estimated to have Mycobacterium tuberculosis infection. It is urgent to develop a rapid, inexpensive and convenient diagnostic method for detection of tuberculosis. Porous silicon material has taken more and more attention in recent years for biosensing applications and some useful results have been obtained. In this paper, we report the feasibility of applying porous silicon microcavity biosensor in a novel and relatively rapid serodiagnostic approach. Nowadays, most of serodiagnostic tests are based on labeled detection. Applying label-free detection methods can help develop fast and e±cient tuberculosis diagnostic tools, which can meet the current demand. In this study, we use this label-free sensing platform (i.e., porous silicon microcavity) to detect the interaction between 16 kDa antigen and anti-16 kDa antibody. Through a series of experiments, we verify the speci¯city and examine the sensitivity of this new diagnostic technique. The results show that it is feasible to apply porous silicon microcavity in the tests of tuberculosis.

Unveiling of the energy storage mechanisms of multi -modified (Nb2O5@C)/rGO nanoarrays as anode for high voltage supercapacitors with formulated ionic liquid electrolytes

Zhang, Jiahe,Zhang, Haitao,Zhang, Yaqin,Zhang, Junwei,He, Hongyan,Zhang, Xixiang,Shim, Jae-Jin,Zhang, Suojiang Elsevier 2019 ELECTROCHIMICA ACTA Vol.313 No.-

Measurement of TOF of fast neutrons with ²³⁸U target

Li, Meng,Guan, Yuanfan,Lu, Chengui,Zhang, Junwei,Yuan, Xiaohua,Duan, Limin,Yang, Herun,Hu, Rongjiang,He, Zhiyong,Wei, Xianglun,Ma, Peng,Gan, Zaiguo,Yang, Chunli,Zhang, Hongbin,Chen, Liang,Qiu, Tianli Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6

We developed a Dual-PPACs detector for fast neutron measurements that consists of two sets of PPAC: conventional PPAC and fission PPAC. A²³⁸U(U₃O₈) coating is placed in the fission PPAC's anode, which is used as the neutrons conversion layer. An experiment was performed to measure neutron time-of-flight (TOF) in which ²⁵²Cf spontaneous fission source was used. An excellent time resolution of 164ps has been observed at 6 mbar in isobutene gas. With the excellent time resolution of Dual-PPACs detector, exact neutron energy can be extracted from the timing measurement. The experimental detection efficiency was 1.9 × 10^-7, consistent with the efficiency of 2.5 × 10^-7 given by a Geant4 simulation. Ultimately, the results show that the Dual-PPACs detector is a suitable candidate for measuring fast neutrons in the future CiADS system.