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1. Effective Transfer of Pretrained Large Visual Model for Fabric Defect Segmentation via Specifc Knowledge Injection

Author

Chen, Zhewei, Wong, Wai Keung, Zhong, Zuofeng, Liao, Jinpiao, and Qu, Ying

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Artificial Intelligence, I.2.10, I.4.9, I.5.4
Abstract

Fabric defect segmentation is integral to textile quality control. Despite this, the scarcity of high-quality annotated data and the diversity of fabric defects present significant challenges to the application of deep learning in this field. These factors limit the generalization and segmentation performance of existing models, impeding their ability to handle the complexity of diverse fabric types and defects. To overcome these obstacles, this study introduces an innovative method to infuse specialized knowledge of fabric defects into the Segment Anything Model (SAM), a large-scale visual model. By introducing and training a unique set of fabric defect-related parameters, this approach seamlessly integrates domain-specific knowledge into SAM without the need for extensive modifications to the pre-existing model parameters. The revamped SAM model leverages generalized image understanding learned from large-scale natural image datasets while incorporating fabric defect-specific knowledge, ensuring its proficiency in fabric defect segmentation tasks. The experimental results reveal a significant improvement in the model's segmentation performance, attributable to this novel amalgamation of generic and fabric-specific knowledge. When benchmarking against popular existing segmentation models across three datasets, our proposed model demonstrates a substantial leap in performance. Its impressive results in cross-dataset comparisons and few-shot learning experiments further demonstrate its potential for practical applications in textile quality control., Comment: 13 pages,4 figures, 3 tables

Published
2023

3. Edge Detection and Deep Learning Based SETI Signal Classification Method

Author

Chen, Zhewei and Haider, Sami Ahmed

Subjects
Computer Science - Computer Vision and Pattern Recognition, Electrical Engineering and Systems Science - Image and Video Processing, Electrical Engineering and Systems Science - Signal Processing
Abstract

Scientists at the Berkeley SETI Research Center are Searching for Extraterrestrial Intelligence (SETI) by a new signal detection method that converts radio signals into spectrograms through Fourier transforms and classifies signals represented by two-dimensional time-frequency spectrums, which successfully converts a signal classification problem into an image classification task. In view of the negative impact of background noises on the accuracy of spectrograms classification, a new method is introduced in this paper. After Gaussian convolution smoothing the signals, edge detection functions are applied to detect the edge of the signals and enhance the outline of the signals, then the processed spectrograms are used to train the deep neural network to compare the classification accuracy of various image classification networks. The results show that the proposed method can effectively improve the classification accuracy of SETI spectrums., Comment: Article submitted to Computers, Materials & Continua

Published
2022

5. ADASYN-Random Forest Based Intrusion Detection Model

Author

Chen, Zhewei, Yu, Wenwen, and Zhou, Linyue

Subjects
Computer Science - Cryptography and Security, Computer Science - Machine Learning
Abstract

Intrusion detection has been a key topic in the field of cyber security, and the common network threats nowadays have the characteristics of varieties and variation. Considering the serious imbalance of intrusion detection datasets will result in low classification performance on attack behaviors of small sample size and difficulty to detect network attacks accurately and efficiently, using Adaptive Synthetic Sampling (ADASYN) method to balance datasets was proposed in this paper. In addition, Random Forest algorithm was used to train intrusion detection classifiers. Through the comparative experiment of Intrusion detection on CICIDS 2017 dataset, it is found that ADASYN with Random Forest performs better. Based on the experimental results, the improvement of precision, recall, F1 scores and AUC values after ADASYN is then analyzed. Experiments show that the proposed method can be applied to intrusion detection with large data, and can effectively improve the classification accuracy of network attack behaviors. Compared with traditional machine learning models, it has better performance, generalization ability and robustness., Comment: Accepted by SPML 2021

Published
2021
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8. Iridium-Catalyzed Silylation of C–H Bonds in Unactivated Arenes: A Sterically Encumbered Phenanthroline Ligand Accelerates Catalysis

Author

Karmel, Caleb, Chen, Zhewei, and Hartwig, John F

Subjects
Benzene Derivatives, Catalysis, Coordination Complexes, Deuterium, Iridium, Kinetics, Ligands, Models, Chemical, Organosilicon Compounds, Phenanthrolines, Chemical Sciences, General Chemistry
Abstract

We report a new system for the silylation of aryl C-H bonds. The combination of [Ir(cod)(OMe)]2 and 2,9-Me2-phenanthroline (2,9-Me2-phen) catalyzes the silylation of arenes at lower temperatures and with faster rates than those reported previously, when the hydrogen byproduct is removed, and with high functional group tolerance and regioselectivity. Inhibition of reactions by the H2 byproduct is shown to limit the silylation of aryl C-H bonds in the presence of the most active catalysts, thereby masking their high activity. Analysis of initial rates uncovered the high reactivity of the catalyst containing the sterically hindered 2,9-Me2-phen ligand but accompanying rapid inhibition by hydrogen. With this catalyst, under a flow of nitrogen to remove hydrogen, electron-rich arenes, including those containing sensitive functional groups, undergo silylation in high yield for the first time, and arenes that underwent silylation with prior catalysts react over much shorter times with lower catalyst loadings. The synthetic value of this methodology is demonstrated by the preparation of key intermediates in the synthesis of medicinally important compounds in concise sequences comprising silylation and functionalization. Mechanistic studies demonstrate that the cleavage of the aryl C-H bond is reversible and that the higher rates observed with the 2,9-Me2-phen ligand are due to a more thermodynamically favorable oxidative addition of aryl C-H bonds.

Published
2019

10. DeepIRES: a hybrid deep learning model for accurate identification of internal ribosome entry sites in cellular and viral mRNAs.

Author

Zhao, Jian, Chen, Zhewei, Zhang, Meng, Zou, Lingxiao, He, Shan, Liu, Jingjing, Wang, Quan, Song, Xiaofeng, and Wu, Jing

Subjects
*CONVOLUTIONAL neural networks, *MACHINE learning, *BLENDED learning, *GENETIC translation, *INDEPENDENT sets, *DEEP learning
Abstract

The internal ribosome entry site (IRES) is a cis -regulatory element that can initiate translation in a cap-independent manner. It is often related to cellular processes and many diseases. Thus, identifying the IRES is important for understanding its mechanism and finding potential therapeutic strategies for relevant diseases since identifying IRES elements by experimental method is time-consuming and laborious. Many bioinformatics tools have been developed to predict IRES, but all these tools are based on structure similarity or machine learning algorithms. Here, we introduced a deep learning model named DeepIRES for precisely identifying IRES elements in messenger RNA (mRNA) sequences. DeepIRES is a hybrid model incorporating dilated 1D convolutional neural network blocks, bidirectional gated recurrent units, and self-attention module. Tenfold cross-validation results suggest that DeepIRES can capture deeper relationships between sequence features and prediction results than other baseline models. Further comparison on independent test sets illustrates that DeepIRES has superior and robust prediction capability than other existing methods. Moreover, DeepIRES achieves high accuracy in predicting experimental validated IRESs that are collected in recent studies. With the application of a deep learning interpretable analysis, we discover some potential consensus motifs that are related to IRES activities. In summary, DeepIRES is a reliable tool for IRES prediction and gives insights into the mechanism of IRES elements. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Correlation analysis of airway‐facial phenotype in Crouzon syndrome by geometric morphometrics: A promising method for non‐radiation airway evaluation.

Author

Zhong, Yehong, Chen, Zhewei, Li, Binghang, Ma, Hengyuan, and Yang, Bin

Subjects
AIRWAY (Anatomy), STATISTICAL correlation, PHENOTYPES, MORPHOMETRICS, PRINCIPAL components analysis
Abstract

Aim: This study aimed to verify the correlation of the airway‐facial phenotype and visualize the morphological variation in Crouzon syndrome patients. Additionally, to develop a non‐radiation methodology for airway assessments. Method: In this study, 22 patients diagnosed with Crouzon syndrome (Age: 7.80 ± 5.63 years; Gender distribution: 11 females and 11 males) were analysed. The soft tissue surface and airway were three‐dimensionally reconstructed, and the entire facial phenotype was topologized and converted into spatial coordinates. Geometric morphometrics was employed to verify the correlation and visualize dynamic phenotypic variation associated with airway volume. A total of 276 linear variables were automatically derived from 24 anatomical landmarks, and principal component analysis (PCA) identified the 20 most significant parameters for airway evaluation. Correlation analyses between parameters and airway volume were performed. Then, patients were classified into three groups based on airway volume, and the differences among the groups were compared for evaluating the differentiating effectiveness of parameters. Results: The facial phenotype was strongly correlated with the airway (coefficient: 0.758). Morphological variation was characterized by (i) mandibular protrusion and anticlockwise rotation; (ii) midface retrusion; (iii) supraorbital frontward and (iv) lengthening of the facial height. All the anthropometric parameters were strongly associated with the airway, and the differences among the groups were statistically significant. Conclusion: This study confirmed the strong correlation between facial phenotype and airway parameters in Crouzon syndrome patients. Despite the development of the airway, pathological midface retrusion was still aggravated, suggesting that surgical intervention was inevitable. Three‐dimensional facial anthropometry has potential as a non‐radiation examination for airway evaluation. [ABSTRACT FROM AUTHOR]

Published
2024
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17. Engineering Conditional Guide RNAs for Cell-Selective Regulation of CRISPR/Cas9

Author

Chen, Zhewei, Chen, Zhewei, Chen, Zhewei, and Chen, Zhewei

Abstract

CRISPR/Cas9 is a versatile platform for implementing diverse modes of genetic perturbation such as gene silencing, induction, deletion, or replacement. This technology is popularly used in developmental biology to probe genetic circuitry via constitutive gene knockdown. Global gene silencing could introduce artifacts in the study of developmental regulatory pathways, and this motivates the development of cell-selective gene editing. Our lab has recently created conditional guide RNAs (cgRNA) that enable CRISPR/Cas9 systems to silence a desired gene Y conditioned on the detection of an RNA transcript X inside of a cell. cgRNA systems were discovered via insertion and deletion mutations that systematically explored the structure function of the guide RNA. Nucleic acid engineering software (NUPACK) was used to generate orthogonal libraries of cgRNA molecules that executed both ON → OFF logic (conditional inactivation by an RNA trigger) and OFF → ON logic (conditional activation by an RNA trigger). A dCas9-based RFP silencing assay in bacteria was developed and used to show these cgRNA sequences were functional and could detect short exogenous trigger sequences in an orthogonal and doseresponsive manner. Subsequent studies on cgRNA structure and function enabled us to engineer next-generation systems that have fewer constraints on the trigger sequence or structure. These next-generation cgRNAs were tested against short synthetic mRNA transcripts, truncated sub-sequences of endogenous mRNAs, and full-length endogenous mRNAs. Synthetic mRNA transcripts were used to study the effect of protein translation on trigger RNA binding. cgRNAs were capable of detecting synthetic sequences embedded in the 3′ UTR of fluorescent protein mRNAs. cgRNAs could also detect short synthetic mRNAs or truncated subsequences from endogenous mRNAs. However, the detection of native full-length endogenous mRNAs remained challenging because we cannot reliably predict the local structure of sub

Published
2023

20. Mask-Free Patterned Perovskite Microcavity Arrays via Inkjet Printing Targeting Laser Emission

Author

Chen, Zhewei, primary, Wu, Junjie, additional, Song, Zheheng, additional, Zou, Yatao, additional, Hu, Jingyun, additional, Li, Ya, additional, Song, Yuhang, additional, Li, Yawen, additional, Bai, Guilin, additional, Li, Xiang, additional, Zhu, Yanan, additional, Zhang, Xinping, additional, Wang, Xue-Dong, additional, Song, Tao, additional, and Sun, Baoquan, additional

Published
2023
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23. Dynamic Morphological Growth Trajectory of Crouzon Population: A Geometric Morphometric Analysis

Author

Zhong, Yehong, Chen, Zhewei, Li, Binghang, Ma, Hengyuan, and Yang, Bin

Abstract

This study is to visualize the morphological growth trajectory of the Crouzon population and provide a more comprehensive and perceptual understanding of pathologic aggregation in terms of maxillofacial and soft tissue surfaces. Twenty-two patients with Crouzon syndrome were included in this retrospective surgery. Preoperative computed tomography was segmented into maxillofacial and soft tissue surface morphologies. Fifty-two anatomical landmarks and a standardized template were used to extract the morphological phenotypes and transform them into spatial coordinates. Geometric morphometrics (GM) were applied to visualize the growth trajectory and estimate the morphological variation of the Crouzon population. Cephalometric analysis was conducted to validate the growth trajectory in a clinical aspect. It was found that both maxillofacial and soft tissue surface morphologies were strongly covaried with age. Morphological development of the Crouzon population was characterized by (1) maxillary retrusion and clockwise rotation, (2) mandibular counterclockwise rotation, (3) facial width narrowing and aggregated concave face, and (4) sunken nasal bone. Pathologic maxillary retrusion continuously existed from infancy to adulthood, and rapid aggravation took place at 3 to 6 years old. In conclusion, this study is the first to visualize the dynamic growth trajectories on both maxillofacial and soft tissue surface morphologies. More attention and monitoring of breathing, snoring, intelligence, and global development should be cast on Crouzon patients between 3 and 6 years old in family care. If any functional abnormalities occur during this period, professional consultations and evaluations should be conducted timely to avoid pathologic aggravation. Consistency between GMs and cephalometry validates the reliability of GM potentials in the clinical field, allowing a promising and revolutionary methodology for dynamically and qualitatively analyzing pathologic changes in some rare congenital diseases.

Published
2024
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24. Pore Fluid Movability in Fractured Shale Oil Reservoir Based on Nuclear Magnetic Resonance.

Author

Liu, Yishan, Chen, Zhewei, Ji, Dongqi, Peng, Yingfeng, Hou, Yanan, and Lei, Zhengdong

Subjects
SHALE oils, PETROLEUM reservoirs, PORE fluids, NUCLEAR magnetic resonance, BASE oils
Abstract

Gulong shale oil is found in a typical continental shale oil reservoir, which is different from marine shale oil reservoirs. The Gulong shale oil reservoir is a pure shale-type oil reservoir with abundantly developed nanoscale pores, making it extremely difficult to unlock fluids. Pressure drive does not easily achieve fluid unlock conditions; thus, it is necessary to utilize imbibition to unlock nanoscale pore fluids. In this study, experiments were conducted on oil displacement by high-speed centrifugal pressure and imbibition under different conditions, respectively, and simulations were used to evaluate the effects of pressure differential drive and imbibition efficiency on the utilization of crude oil following fracturing. Combined with the mixed wettability of the reservoir, the imbibition efficiency was analyzed, and the imbibition efficiency at different soaking stages was evaluated. When the fracturing pressure was higher than the matrix pore pressure, the imbibition efficiency was the most obvious, which was 27.9%. Spontaneous imbibition depending solely on capillary force had poor efficiency, at 16.8%. When the fracturing pressure was lower than the matrix pore pressure, the imbibition efficiency was the lowest, at only 1.3%. It is proposed that strengthening fracture pressure and promoting pressurized imbibition are the keys to improving shale oil development. [ABSTRACT FROM AUTHOR]

Published
2023
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38. Feasibility study of improved unconventional reservoir performance with carbonated water and surfactant

Author

Zhenhua Rui, Xuefeng Qu, Xin Lu, Kegang Ling, Shirish Patil, Junhui Liu, Jun Lu, Zhonglin Yang, Haiyang Yu, and Chen Zhewei

Subjects
Petroleum engineering, Gas breakthrough, 020209 energy, Mechanical Engineering, Water injection (oil production), Tight oil, 02 engineering and technology, Building and Construction, Water flooding, Pollution, Industrial and Manufacturing Engineering, General Energy, 020401 chemical engineering, Pulmonary surfactant, Injection volume, 0202 electrical engineering, electronic engineering, information engineering, Environmental science, Enhanced oil recovery, 0204 chemical engineering, Electrical and Electronic Engineering, Sensitivity analyses, Civil and Structural Engineering
Abstract

For unconventional reservoirs, water flooding performs poorly because of low displacement efficiency; gas flooding shows limited enhanced oil recovery (EOR) capability due to gas breakthrough. Carbonated water injection (CWI) and active CWI (ACWI) are promising EOR methods which combine advantages of water and gas flooding. This paper provides experimental and numerical studies of carbonated water and surfactant injection based on a case study in Changqing Oilfield, China, which is the first time to investigate the feasibility of CWI and ACWI for tight oil reservoirs. This study compares performances of active water injection (AWI), CWI, Water altering gas (WAG), and ACWI. Experimental results reveal that the oil recovery of CWI is 2.7% more than WAG. ACWI achieves the highest incremental oil recovery (9.43%) among four methods. The sensitivity analyses of ACWI + WAG is further implemented experimentally, which demonstrates that ACW as a pre-flood improves 7% of oil recovery during WAG process. For Changqing tight reservoir cores, the optimal injection volume of ACW is 0.8 pore volume. Numerical simulations are conducted to validate the capability of cubic Equation-of-State coupled with Henry's law (EOS/H model) for CWI in tight oil reservoirs, indicating EOS/H model is applicable to correlate phase behavior of carbonated water and oil system. This paper, for the first time, investigates the EOR performance of ACWI in tight oil reservoirs. These results explore the feasible application of using CWI/ACWI in tight oil reservoir development.

Published
2019

39. A compositional model for CO2 flooding including CO2 equilibria between water and oil using the Peng–Robinson equation of state with the Wong–Sandler mixing rule

Author

Jian-Zheng Su, Zhonglin Yang, Chen Zhewei, Haiyang Yu, and Shiqing Cheng

Subjects
Equation of state, Materials science, Science, Energy Engineering and Power Technology, Thermodynamics, 02 engineering and technology, Numerical simulation, 010502 geochemistry & geophysics, 01 natural sciences, CO2 flooding, 020401 chemical engineering, Geochemistry and Petrology, Phase (matter), Fugacity, 0204 chemical engineering, Solubility, Wong–Sandler mixing rule, 0105 earth and related environmental sciences, Petrology, chemistry.chemical_classification, Aqueous solution, Aqueous two-phase system, QE420-499, Geology, Geotechnical Engineering and Engineering Geology, Geophysics, Fuel Technology, Hydrocarbon, chemistry, Economic Geology, CO2 solubility
Abstract

This paper presents a three-dimensional, three-phase compositional model considering CO2 phase equilibrium between water and oil. In this model, CO2 is mutually soluble in aqueous and hydrocarbon phases, while other components, except water, exist in hydrocarbon phase. The Peng–Robinson (PR) equation of state and the Wong–Sandler mixing rule with non-random two-liquid parameters are used to calculate CO2 fugacity in the aqueous phase. One-dimensional and three-dimensional CO2 flooding examples show that a significant amount of injected CO2 is dissolved in water. Our simulation shows 7% of injected CO2 can be dissolved in the aqueous phase, which delays oil recovery by 4%. The gas rate predicted by the model is smaller than the conventional model as long as water is undersaturated by CO2, which can be considered as “lost” in the aqueous phase. The model also predicts that the delayed oil can be recovered after the gas breakthrough, indicating that delayed oil is hard to recover in field applications. A three-dimensional example reveals that a highly stratified reservoir causes uneven displacement and serious CO2 breakthrough. If mobility control measures like water alternating gas are undertaken, the solubility effects will be more pronounced than this example.

Published
2019

41. Coffee‐Stain‐Free Perovskite Film for Efficient Printed Light‐Emitting Diode

Author

Li, Ya, primary, Chen, Zhewei, additional, Liang, Dong, additional, Zang, Jiaqing, additional, Song, Zheheng, additional, Cai, Lei, additional, Zou, Yatao, additional, Wang, Xuechun, additional, Wang, Yusheng, additional, Li, Pandeng, additional, Gao, Xingyu, additional, Ma, Zhongsheng, additional, Mu, Xinju, additional, El‐Shaer, Abdelhamid, additional, Xie, Liming, additional, Su, Wenming, additional, Song, Tao, additional, and Sun, Baoquan, additional

Published
2021
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42. Temporomandibular joint dislocation in patients with cleft lip and palate after maxillary distraction osteogenesis

Author

Wang, Binqing, Zhai, Junya, Zheng, Yilue, Tong, Haizhou, Lü, Yang, Chen, Zhewei, Yin, Ningbei, and Song, Tao

Subjects
cleft palate, temporomandibular joint dislocation, Male, maxillary distraction osteogenesis, maxillofacial malformation, Adolescent, Cleft Lip, Joint Dislocations, Osteogenesis, Distraction, Temporomandibular Joint Disorders, Internal Fixators, stomatognathic diseases, Young Adult, Treatment Outcome, stomatognathic system, Maxilla, Humans, Female, Clinical Case Report, Child, Research Article, Follow-Up Studies
Abstract

Introduction: Distraction osteogenesis (DO) is a widely used for cleft and palate related maxillary hypoplasia. There has been little research on temporomandibular joint (TMJ) dislocation after maxillary DO. We present these 3 cases and analyze the possible causes for reference by other clinicians. Patient concerns: In the late stages of maxillary DO, the patients gradually felt a decrease in mandibular mobility and suffered from limited mouth opening. Case 2 and 3 could open their mouth up to 1 and 2 fingers and Case 1 barely able to open her mouth at the completion of distraction. Diagnosis: Case 1 and Case 3 were diagnosed as right TMJ dislocation and Case 2 had a TMJ dislocation on her left side. Interventions: Patients with TMJ dislocation were repositioned with manipulation as soon as detected. Outcomes: There was no recurrence in all three cases during the postoperative follow-up period. Conclusions: Maxillary DO can sufficiently advance the maxilla in cleft lip and palate patients. Clinicians should be mindful of the TMJ dislocations that maxillary DO can exert on patients.

Published
2021

49. Simulation Study of Allied In-Situ Injection and Production for Enhancing Shale Oil Recovery and CO2 Emission Control

Author

Chen Zhewei, Haiyang Yu, Xuefeng Qu, Shiqing Cheng, Qichao Xie, and Qi Songchao

Subjects
Control and Optimization, Gas breakthrough, 020209 energy, Water injection (oil production), Energy Engineering and Power Technology, Injection rate, Improved method, 02 engineering and technology, Sweep efficiency, lcsh:Technology, chemistry.chemical_compound, 020401 chemical engineering, CO2 huff and puff, Shale oil, 0202 electrical engineering, electronic engineering, information engineering, enhanced oil recovery, 0204 chemical engineering, Electrical and Electronic Engineering, shale oil reservoirs, Engineering (miscellaneous), Petroleum engineering, Renewable Energy, Sustainability and the Environment, lcsh:T, allied in-situ injection and production (AIIP), chemistry, Carbon dioxide, Environmental science, Enhanced oil recovery, Energy (miscellaneous)
Abstract

The global greenhouse effect makes carbon dioxide (CO2) emission reduction an important task for the world, however, CO2 can be used as injected fluid to develop shale oil reservoirs. Conventional water injection and gas injection methods cannot achieve desired development results for shale oil reservoirs. Poor injection capacity exists in water injection development, while the time of gas breakthrough is early and gas channeling is serious for gas injection development. These problems will lead to insufficient formation energy supplement, rapid energy depletion, and low ultimate recovery. Gas injection huff and puff (huff-n-puff), as another improved method, is applied to develop shale oil reservoirs. However, the shortcomings of huff-n-puff are the low sweep efficiency and poor performance for the late development of oilfields. Therefore, this paper adopts firstly the method of Allied In-Situ Injection and Production (AIIP) combined with CO2 huff-n-puff to develop shale oil reservoirs. Based on the data of Shengli Oilfield, a dual-porosity and dual-permeability model in reservoir-scale is established. Compared with traditional CO2 huff-n-puff and depletion method, the cumulative oil production of AIIP combined with CO2 huff-n-puff increases by 13,077 and 17,450 m3 respectively, indicating that this method has a good application prospect. Sensitivity analyses are further conducted, including injection volume, injection rate, soaking time, fracture half-length, and fracture spacing. The results indicate that injection volume, not injection rate, is the important factor affecting the performance. With the increment of fracture half-length and the decrement of fracture spacing, the cumulative oil production of the single well increases, but the incremental rate slows down gradually. With the increment of soaking time, cumulative oil production increases first and then decreases. These parameters have a relatively suitable value, which makes the performance better. This new method can not only enhance shale oil recovery, but also can be used for CO2 emission control.

Published
2019
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50. Allied In-Situ Injection and Production for Fractured Horizontal Wells to Increase Hydrocarbon Recovery in Tight Oil Reservoirs: A Case Study in Changqing Oilfield

Author

Chen Zhewei, Zhonglin Yang, Haiyang Yu, Bo Xian, Shiqing Cheng, and Youan He

Subjects
In situ, chemistry.chemical_classification, Petroleum engineering, Horizontal wells, Tight oil, 02 engineering and technology, Sweep efficiency, 010502 geochemistry & geophysics, 01 natural sciences, Hydrocarbon, 020401 chemical engineering, chemistry, 0204 chemical engineering, Geology, 0105 earth and related environmental sciences
Abstract

Poor energy supplement and low hydrocarbon recovery are the two main shortcomings for water or gas injection in tight oil reservoir development. Horizontal well flooding can improve oil recovery and sweep efficiency of water flooding. However, the economic benefits need to be considered for long horizonal well injection. Based on a case of Changqing Oil filed, this paper presents a novel development approach, Allied In-Situ Injection and Production (AIIP), for fractured horizontal wells to increase hydrocarbon recovery, and explores its feasibility with simulation work, compared with traditional water flooding method. The impact for the existence of natural fractures in tight oil reservoir is also studied in this work. Although requiring costly special equipment, a series of simulations prove that AIIP is a more reliable and efficient approach to increase the performance of fractured horizontal wells compared to conventional methods, oil recovery and oil rate were improved significantly after AIIP was conducted. Water injectivity increased sharply than traditional water flooding with a lower injection pressure. The existence of natural fracture in tight oil formation improved the water flow inside the formation, leading better sweep efficiency and higher oil recovery factor. However, water cut in producers increased faster in natural facture enriched model than that of basic model. Thereforem it is essential to evaluate the performance of AIIP process before application.

Published
2019

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