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Collaborating Authors
University of Science & Technology Beijing
A Novel Approach for Modeling Gas Flow Behaviors in Unconventional Reservoirs with Nanoporous Media
Song, Hongqing (University of Science & Technology Beijing) | Li, Zhengyi (University of Science & Technology Beijing) | Wang, Yuhe (Texas A&M University at Qatar) | Zhu, Weiyao (University of Science & Technology Beijing) | Cao, Yang (Texas A&M University) | Killough, John (Texas A&M University)
Abstract With the technology advancement in unconventional reservoirs development, more and more attention has been paid to nanoporous flow which is believed to play a central role in understanding fluid flow behaviors in unconventional reservoirs. Previous studies have performed unconventional reservoir analysis using more conventional reservoir simulation techniques. However, conventional numerical simulation techniques are computationally expensive and do not understand fluid flow behaviors well in terms of theory basis. In this paper, we first present a new motion equation considering diffusion and convection and Lattice Boltzmann method is applied to model the gas flow characteristics to obtain the important parameters in the new general equation. Then the mathematical model of gas flow behaviors in multi-scale medium were proposed and established based on theoretical analysis of transport mechanism via molecular kinetic theory. The pressure distribution equations of radial and linear flow were derived for different flow regimes analytically, and the computation method of the control area of gas well was presented. Additionally, the semi-analytical equations of volumetric flow rate for horizontal fractured wells were obtained. At last through Newton iterative method, the non-linear volumetric flow rate was analyzed, considering various factors such as SRV permeability, unstimulated shale permeability, and diffusion coefficient. Barnett shale production data is used to calibrate and validate this new approach. According to the results, the volumetric flow rate of the gas well increases when the diffusion coefficient grows. Consequently diffusion in unconventional reservoirs with nanoporous media plays an important role. With changing the average pore diameters, different results are simulated and calculated by LBM and the most appropriate values can be confirmed by comparing the experimental results. Besides, the intrinsic permeability of unstimulated shale and permeability of SRV are also found have apparent positive correlation with the gas productivity.
- Europe (0.93)
- North America > United States > Texas (0.88)
- North America > United States > Texas > Fort Worth Basin > Barnett Shale Formation (0.99)
- Asia > China > Sichuan > Sichuan Basin (0.99)
Topological Data Analysis to Solve Big Data Problem in Reservoir Engineering: Application to Inverted 4D Seismic Data
Alfaleh, Abdulhamed (Saudi Aramco) | Wang, Yuhe (Texas A&M University at Qatar) | Yan, Bicheng (Texas A&M University) | Killough, John (Texas A&M University) | Song, Hongqing (University of Science & Technology Beijing) | Wei, Chenji (PetroChina)
Abstract Data analysis is one of the most important topics in any industry. In petroleum engineering, the large, complex, and multi-dimensional reservoir data sets (big data) presents a challenge for engineers to study the masses of unstructured information and make decisions. A new approach to analyze complex data is called Topological Data Analysis (TDA) which aims to extract meaningful information from such data. TDA relies on the concept that complex data has shapes where shape has meanings. It analyzes the shape of complex data, identifying clusters and their statistical significance. The objective of this paper is to introduce TDA to reservoir engineering using an example of inverted 4D seismic data for studying reservoir connectivity and compartmentalization. In this paper, we introduce the principles of TDA and discuss its potential in reservoir engineering, which could allow identification of reservoir engineering data behavior, recognition of new opportunities, detection of anomalies and events, and minimizing uncertainties. The TDA procedures are introduced using inverted 4D seismic data set to study reservoir connectivity and compartmentalization. The process to generate and process the data set is explained. Similarity distance function and lenses are defined and used to create TDA graphs for feature identification and analysis. It is shown that TDA is able to predict the compartmentaliztion of the reservoir models with various process configurations. Variance normalized Euclidean and topological neighborhood function are used successfully to compartmentalize the reservoir model. Using normalized input dataset, correlation and principle component analysis also create similar compartments. The success of TDA in discovering meaningful patterns is attributed to the similarity distance function representing the objective of study, one or more lenses exposing the data, and the right combination of input data, similarity distance function and lenses. A promising big data analysis method, TDA, is introduced to reservoir engineering application with principles, procedures and examples. It has been shown that TDA can automatically discover critical intelligence within the 4D seismic data set for studying reservoir connectivity and compartmentalization, which are essential to the accuracy of forecasts and development plans, the validity of reservoir simulation, and the success of performance diagnostics and optimization.
- Europe > Norway > Norwegian Sea (0.46)
- North America > United States > Texas (0.28)
- Asia > Middle East (0.28)
- Geophysics > Time-Lapse Surveying > Time-Lapse Seismic Surveying (1.00)
- Geophysics > Seismic Surveying (1.00)
- Europe > Norway > Norwegian Sea > Ile Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 128 > Block 6608/10 > Norne Field > Tofte Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 128 > Block 6608/10 > Norne Field > Not Formation (0.99)
- (4 more...)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Four-dimensional and four-component seismic (1.00)
- Data Science & Engineering Analytics > Information Management and Systems > Data mining (1.00)
An Absolute Magnetic Rotary Encoder Based on Kalman Filter
Wang, Qi (University of Science & Technology Beijing) | Zhang, Bo (University of Science & Technology Beijing) | Tian, Yue (University of Science & Technology Beijing) | Sun, Ming Ming (University of Science & Technology Beijing)
Abstract This paper demonstrates the development of a magnetic rotary encoder, which is applied to the windward system of offshore wind farms. The encoder is equipped with a magnetic sensor for detecting a rotary magnetic field's direction change in a non-contact way in order to meet the harsh requirements of the offshore platforms, especially those drilling platforms with water and oil in their working sites. Thus the encoder is invulnerable to water, oil, dust, salt spray, vibration, impact, etc. and is suitable for various systems including the motor servo system, the feedback system of rotational position of booms and the height locating system of hydraulic cranes. The encoder also achieves a resolution as high as 16 bits. And to deal with the instability of the original signal, a modified-version Kalman filter is proposed and applied, which also surpasses the original Kalman filter in term of the encoder's response speed. Finally the output of the encoder is calibrated by using piecewise linearity methods and as a result the absolute error of encoder is limited within 0.03 degree i.e. 0.01%FS.
Study on the Performance of Magnesium Sacrificial Anode
Gao, Jiawei (University of Science & Technology Beijing) | Du, Yanxia (University of Science & Technology Beijing) | Tang, Dezhi (University of Science & Technology Beijing) | Li, Xiaxi (Beijing Gas Group) | Yan, Danping (Beijing Gas Group)
Abstract In this work, the service performance of magnesium sacrificial anodes used to protect urban gas pipelines from corrosion were investigated by both field tests and laboratory measurements. It was found that the consumption of magnesium sacrificial anode increases with increasing service time and the poorer coating performance. Moreover, the more negative the open circuit potential of magnesium sacrificial anode, the larger the consumption will be. And it is worth noting that the positive shift of pipeline open circuit potential(Vopc-p) leads to the decrease of consumption when Vopc-p is more negative than -1.2V CSE. When Vopc-pis nobler than -1.2V CSE, the positive shift of Vopc-p, however, will result in the increase of consumption. Based on the field tests and laboratory experiments results, the mechanisms were explored, which are of great value for the maintenance and lifetime prediction of sacrificial anode in urban gas pipelines CP system.
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Piping design and simulation (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.92)
Effect of Alternating Current on Corrosion of Pipeline Steel
Tang, Dezhi (University of Science & Technology Beijing) | Du, Yanxia (University of Science & Technology Beijing) | Lu, Minxu (University of Science & Technology Beijing) | Wu, Guangchun (University of Science & Technology Beijing) | Liang, Yi (University of Science & Technology Beijing) | Jiang, Zitao (University of Science & Technology Beijing)
Abstract In this work, effect of alternating current (AC) on corrosion behavior of pipeline steel in the presence of sacrificial anode or grounding were investigated in 4g/L Na2SO4 simulated soil solution by weight loss tests, electrochemical measurements and electrochemical analyses. It is found that the imposed AC shifts both potential of pipeline steel and sacrificial anode (or grounding) away from the value prior to AC. The difference of the offsets results in an enhanced DC current between pipeline and sacrificial anode (or grounding). As a consequence, corrosion of pipeline is accelerated or controlled, which is close related to the electrochemical characteristic of sacrificial anode (or grounding). Based on experiment results, a mixed AC corrosion mechanism considering effect of AC on the interactions between pipeline steel and appurtenances, i.e., sacrificial anode and grounding is proposed.
Study on CP Criteria for Mild Steel in the Presence of AC
Tang, Dezhi (University of Science & Technology Beijing) | Lu, Minxu (University of Science & Technology Beijing) | Du, Yanxia (University of Science & Technology Beijing) | Jiang, Zitao (University of Science & Technology Beijing) | Dong, Liang (University of Science & Technology Beijing)
ABSTRACT The traditional cathodic protection () criteria of "-850mV CSE" is no longer effective when pipelines are exposed to alternating current () interference. Unfortunately, the criteria for buried pipelines in the presence of interference have not reached a consensus so far. In this work, weight loss tests on mild steel in the simulating soil solution of 4 g/L Na2SO4 were conducted to explore the reasonable potential for mild steel under interference. The experimental results show that the corrosion rates of mild steel under different potentials were affected significantly by current and the effects depended on the applied current density. In addition, induced corrosion can be controlled by increasing level when current density was below 300A·m. However, the corrosion of mild steel would be accelerated when the potentials were too negative. Finally, a reasonable potential range for mild steel in the presence of interference was proposed basing on the experimental results.
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.48)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
In-Situ Observation of Corrosion-Enhanced Dislocation Emission and Motion Resulting in Initiation of Stress Corrosion Cracking
Chu, Wu-Yang (University of Science and Technology) | Gao, Biao GuKe-Wei (University of Science and Technology) | Huang, Yi-Zhong (University of Science and Technology) | Xiao, Ji-Mei (University of Science & Technology Beijing)
ABSTRACT A special constant deflection device for TEM was used to study the change in dislocation configuration ahead of a crack tip during stress corrosion cracking (XC) of brass in water and of Ti-24Al-IlNb alloy in methanol as well as the initiation of SCC. In situ tensile test in TEM for brass was carried out to compare. The results show that corrosion process itself during SCC can enhance dislocation emission, multiplication and motion as well as a dislocation free zone (DFZ) is formed. When the corrosion - enhanced dislocation emission and motion reaches certain a condition a nanocrack of SCC initiates in the DFZ or from the crack tip. Because of the action of the corrosion solution the nanocrack of SCC propagates into a cleavage or intergranular microcrack rather than blunts into a void like in situ tension in TEM. 1. INTRODUCTION Many different mechanisms about stress corrosion cracking (SCC) under anodic dissolution control have been proposed ( ?-* I The mechanism that dissolution enhanced localized plasticity results in see ? 6-8 ? is based on the experimental fact that anodic polarization can promote ambient creep for various metals and alloys I?- ) Kaufman indicated that the density of dislocations in a region very close to the fracture surface of SCC was much higher than that far away from the fracture surface ? ? ? Up to now, however, direct proof of corrosion-enhanced dislocation emission. multiplication and motion is lacking. In situ tensile tests in transmission electron microscope (TEM) is the most direct and powerful method for studying dislocation emission, multiplication and motion ? - ? Swann et al 51 studied the dislocation configuration after SCC in TEM, but did not study the effect of corrosion on dislocation emission and motion. Since there is no way to put the solution into TEM, a constant deflection device for TEM has been designed ? ? and then the effect of corrosion on dislocation emission and motion can be investigated based on the change in dislocation configuration ahead of a loaded crack tip after corroded for some time but before the initiation of SCC. The fust aim of the present work is to prove that corrosion process itself can enhance dislocation emission and motion before the initiation of SCC. In situ tensile tests in TEM showed that for both ductile ? ?*- ? and brittle ? ?+ -? materials, many dislocations could be emitted from a loaded crack tip and moved away from the crack tip, then a dislocation free zone (DFZ) formed under constant displacement, The stress in the elastic DFZ might be up to the cohesive strength and then a nanocrack initiated in the DFZ or from the blunted crack tip ? ?3-?4, ?7-?8 ? In ductile material, the nanocrack would quickly blunt into a void or a notch under constant displacement ? I3 I. In brittle material, the nanocrack would propagate into a cleavage crack rather than blunt ? 17- ? Therefore, the essential difference between ductile and brittle fracture is the different action of the nanocrack after its initiation, All SCC failures controlled by the anodic dissolution mechanism have macroscopic appearance of brittleness ? I-3 ) in common. Does the ductile/brittle transition induced by SCC obey the same rule? Therefore, the second aim of the present work is to compare the initiation and propagation of a nanocrack of brass in vacuum with that in solution to reveal the nature