bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Seismic Data Conditioning of the Bioclastic Limestone in the Middle East
Authors: Lin Tengfei , Wang Xueling , Dong Junchang 
Published: April 2019

Abstract
The bioclastic limestone reservoirs of Cretaceous period occupy an important position in the petroleum industry of Middle East. It is the carbonate heterogeneity that is challenging the accuracy of the reservoir prediction, which brings forward higher requirements for the seismic data quality. Besides, some seismic data are processed more than 10 years ago, the signal to noise ratio (SNR) is relative low due to the random noise and coherent noise like acquisition footprint anomalies. The acquisition footprint artifacts caused by acquisition and processing seriously suppress the true stratigraphic features, which can result in pitfalls in seismic interpretation, seismic attribute analysis as well as seismic inversion. While the pre-stack seismic data is usually unavailable, which means that the noise can hardly be subtracted by conventional pre-stack seismic processing workflows, such as statics, high-resolution velocity analysis and ground roll attenuation. Consequently, a comprehensive post-stack seismic data conditioning workflow is necessary to solve the above problems.
In order to improve the post-stack seismic data quality, a comprehensive data conditioning workflow are applied for noise suppression. Firstly, structural-oriented filtering is utilized to attenuate random noise and partial acquisition footprint artifacts. Then 2D waveform transform of seismic amplitude and filtered seismic attribute in x-y domain are calculated, to separate acquisition footprint anomalies (large wave number in kx-ky domain) from true structural signal (small wave number in kx-ky domain) by interactive analysis. The application of Laplace-Gaussian (LoG) filter deserves an obvious improvement in acquisition footprint suppression workflow. The comprehensive noise attenuation workflow in this paper can effectively remove both periodic and non-periodic noise to obtain higher signal to noise ratio (SNR) for post-stack seismic volume. In this way, the stratigraphic features (tidal-channel, reef-beach complex) can be more clearly depicted and some artifacts caused by noise will disappear in seismic attribute calculation, seismic inversion and reservoir prediction.
Adverse Effect of Oversizing Upstream Gas Oil Separation Plants on Energy Consumption
Authors: Soliman Mohamed Ahmed 
Published: April 2019

Abstract
The objective of this paper is to highlight the adverse effect of oversizing upstream surface facilities on energy consumption and different techniques to improve the energy performance of these oversized facilities. Oversizing may provide short-term gain as insurance policy for the design team but long-term loss for the operating organization.
In this paper, the mindset and consequences of oversizing surface facilities rotating equipment, piping, and heat exchangers on energy consumption are depicted with real-life case studies. In addition, a systematic approach to eliminate oversizing in Greenfield projects and to mitigating their adverse effects on existing facilities are addressed in detail. The paper focuses on a comprehensive case study of oversizing crude charge pumps in one of the gas oil separation plants GOSPs (Plant-A).
Extensive process simulation using Hysys and benchmarked by the actual plant energy consumption data indicated that oversizing of pumps, heat exchangers, and compressors increase energy consumption dramatically and lower the overall plant performance. It was observed that one of the several reasons for oversizing plant equipment is attributed to the lack of clear guidelines from the proponent governing the maximum design margins allowed. Adequately sized plant equipment will improve plant reliability, minimize energy consumption and plant maintenance, and improve plant safety.
Application of Fuzzy Control Theory in the Study of the Macroscopic Remaining Oil Distribution for a Mature Sandstone Reservoir in the Tarim Oilfield, China
Authors: Sun Jian , Li Chenyang , Zhang Zekai , Ren Long , Li Qi , Chen Mingqiang , Zhang Bo , Tang Kang 
Published: April 2019

Abstract
Research on macroscopic remaining oil distribution (MROD) has become a worldwide issue and not yet been satisfactorily solved in oil industry. At present, the commonly used methods for determining MROD are heavy workload, long time consuming and greatly influenced by human factors. In the research of MROD, geological factors are uncontrollable and development factors are controllable. Therefore, under certain development conditions, geological factors determine the MROD. This paper mainly studies MROD in geological factors.
The new approach is based on development geological principles. It uses fuzzy control theory to predict MROD. Firstly, according to structural location from high to low and clay content from much to less, the structural location parameters and sedimentary microfacies parameters are fuzzified into 5 grades respectively. Secondly, according to the hydrocarbon potential from good to poor, the oil and gas universe is fuzzified into 5 grades. Finally, fuzzy control rules were established. It can be calculated by characteristic expansion method. Complete governing equations are provided and the method is described in detail to permit readers to replicate all results.
The method of using fuzzy control theory to predict MROD has been successfully applied in Tarim oilfield. According to the range of tectonic height and clay content, the membership degrees of structural location parameters and sedimentary microfacies parameters are assigned respectively. LN2-G well in research region is chosen as an example for study. The characteristic coefficients corresponding to LN2-G well under different structure and sedimentary conditions are respectively obtained. Through the fuzzy control statement, and combining the principle of maximum membership degree, the oil level in the target formation of well LN2-G can be calculated, which value is 5, corresponding to the oil layer. Then we use the existing exploration wells in research region, and use the above method to calculate them respectively. Based on the calculated results, we draw the remaining oil distribution level range prediction plan. Finally, we selected 3 wells to verify the accuracy of the prediction. It shows that the reservoirs drilled by LN2-X, LN2-Y and LN2-Z wells are water layer, water layer and poor oil layer, respectively. The actual drilling results of these 3 wells are water layer, water layer and oil-bearing water layer, which are completely consistent with the prediction results.
This research can accurately forecast the MROD based on the analysis of the essential factors (geological factors) affecting the MROD. The method is convenient and economical, which provides a reliable basis for the remaining oil development.
A Reservoir and Geomechanical Coupling Simulation Method: Case Studies in Shale Gas and CBM Reservoir
Authors: Tang Xuanhe , Zhu Haiyan , Liu Qingyou , Song Yujia 
Published: April 2019

Abstract
To investigate the time-lapse, three-dimensional (so-called four dimensional/4D) stress during production/injection, a 4D multi-physical modeling method is proposed. A finite difference method (FDM) reservoir simulator is used to couple thermal-hydrological-chemical (THC) processes, while a finite element method (FEM) geomechanical simulator takes on the role of a thermal-hydrological-mechanical (THM) coupling calculator. Heterogeneity and anisotropy of the reservoir flow and geomechanical properties as well as the permeability stress-sensitivity can be considered in modelling based on field and experimental data. In order to couple the flow model with the geomechanical model, an improved interface (coupling) Python code is provided to communicate data between the finite difference (FD) and finite element (FE) grids. Ultimately, this method is applied to analyze the stress and poro-elastic parameters evolution of hydraulic fractured Sichuan Basin shale gas reservoir and Qinshui Basin coalbed methane (CBM) reservoir in production.
An Equivalent Media Theory for Reservoir Characterization
Authors: Prajapati Srichand , Ghosh Deva 
Published: April 2019

Abstract
The existence of elastic anisotropy in the reservoir is obtained through the equivalent media theory. An isotropic elastic theory fairly explains the reservoir modeling or characterization but its not well explain anisotropic characteristic fairly for reservoir characterization which is extremely challenging without considering a self-consistent theory of effective equivalent media theory. In this research, equivalent media theory has been explained and implemented on a producing well-log data with consistent Vp, Vs, density and other parameters. Instead of using Voigt averaging, equivalent media theory used to estimate the effective stiffness parameters and compare with Thomsen's parameters and finally used effective anisotropy parameters and compare with gamma log. Result shows the effectiveness of equivalent media theory for future application for developing reservoir modeling and characterization.
Recent Development and Remaining Challenges of Iron Sulfide Scale Mitigation in Sour Gas Wells
Authors: Chen Tao , Wang Qiwei , Chang Frank , Aljeaban Norah 
Published: April 2019

Iron sulfide scale deposition can be a significant flow assurance issue in the sour gas production systems. It can deposit along the water flowing path from near wellbore reservoir area to surface equipment, which results in formation damage, causes tubing blockage, interferes with well intervention, and reduces hydrocarbon production.The main objectives of this paper are to review on the new advancements and remaining challenges of iron sulfide scale management in sour gas wells, covering the mechanisms of iron sulfide formation; the mechanical and chemical removal techniques; and the prevention strategies.This paper gives a special emphasis to the different mechanisms of iron sulfide formation during well completion and production stages, especially the sources of ferrous iron for scale deposition. It is essential to understand the root-cause in order to identify and develop suitable technologies to manage the scale problem. The paper also summarizes the latest developments in mechanical methods and chemical dissolvers for the removal of iron sulfide deposited on downhole tubing. The capabilities of the current chemical dissolvers is discussed and the criteria of effective dissolvers are provided to serve as a guide for future development. Then the paper provides an overview of recent developments on iron sulfide prevention technologies and treatment strategies. It differentiates the treatment approaches for corrosion byproduct and scale precipitation and scale inhibitor deployment through continuous injection and squeeze treatment. Finally, the paper outlines the technical gaps and areas for further research and development efforts.This paper provides the latest review on irons sulfide formation and mitigation with an attempt to integrate viable solutions and expose workable practices.
Higher Precision Automated Managed Pressure Drilling Control Achieved Through the Addition of a Thermal Model
Authors: Gu Qifan , Fallah AmirHossein , Ambrus Adrian , Chen Dongmei , Ashok Pradeepkumar , van Oort Eric 
Published: April 2019

For a robust and efficient automated Managed Pressure Drilling (MPD) operation, the choke controller requires an accurate hydraulics model that can be run at minimum computational expense. Integration of a suitable thermal model would improve the accuracy of the hydraulics model used by the choke controller. The use of existing thermal models, however, comes with additional computational costs that are a hurdle when aiming to achieve real-time control at sufficiently fast time-scales.
In this paper, a quasi-steady thermal model is integrated with an automated MPD control approach that uses a reduced Drift-Flux Model (RDFM) to describe the hydraulics of multiphase flow in real-time. This integrated modeling approach provides the dynamic temperature profile along a well without increasing the computational expense. The energy equation is solved using the finite-difference method (FDM) in an explicit scheme, with all the temperature-dependent parameters updated in accordance with the calculated temperature profile in each computation step. The RDFM is also reformulated to account for the heat transfer between the gas and the surroundings. This modified model is then incorporated into an automated observer algorithm to estimate parameters, e.g. volume of gas expansion (dependent on temperature), which are used by the controller for choke opening manipulation.
Validations are first conducted in a simulation environment for the scenario with a dynamic temperature profile along the well. The results indicate that the proposed modeling approach offers significant improvement compared to approaches which do not consider thermodynamics. A good agreement of the temperature results is observed between the proposed approach and existing models as well as commercial software. Case studies are also conducted for two scenarios to demonstrate the utility of the proposed integrated thermal and hydraulics model. Simulation results indicate that the proposed modeling approach can generate more accurate estimations of unmeasurable variables, which leads to a better performance of the choke manipulation. It should be noted that when employing the modified RDFM with a finite difference scheme, the computational cost is minimized. On a standard laptop computer, the computational time to simulate an entire well is of the order of 70ms for 1s sensor data sampling. Therefore, the proposed thermal and hydraulics model provides an enabling tool for a faster and more precise control of MPD systems.
Integrated Formation Evaluation Using Novel Neutron Correction in the Presence of Trace Elements
Authors: Zhang Hao , Alarcon Nora , Mendez Freddy 
Published: April 2019

Abstract
The estimation of formation porosity in particular and formation volumetrics in general are key to any reservoir evaluation as they establish the hydrocarbon storage capacity. Compensated neutron porosity is one of the most common measurements incorporated in any log-based volumetric analysis. However, this type of measurement is strongly affected by the presence of trace elements, especially in clay rich formations. Trace elements, such as boron and gadolinium, have very high neutron capture cross-sections and absorb large amounts of thermal neutrons in the formation. Whenever these elements are present in concentrations exceeding just a few parts per million they have a significant effect on overall thermal neutron capture, yielding high apparent neutron porosity. When the measurement is included in an integrated log analysis system, this results in inaccurate formation porosity and matrix volumes. A reliable neutron porosity correction method is therefore needed to improve petrophysical evaluation in in such logging environments.
In this work, an integrated model is proposed to correct the compensated neutron response using pulsed neutron spectroscopy measurements and other conventional log data. A joined inversion method is implemented which obtains an improved neutron response by removing the undesirable contributions by the trace elements which are not a part of the formation petrophysical model.
The proposed model is validated, by applying it to several data sets from different shale plays in North America and Latin America, and comparing the results against core analysis data. Due to presence of rich trace elements in the formation, without the correction model, the original processing results indicate up to 50% higher formation porosity when compared with core measurements. After applying the proposed correction, the porosity comparison is dramatically improved, matching the reference core porosity.
The proposed model offers an effective, integrated analysis method, in challenging unconventional clay-rich shale environments, for correct estimation of formation porosity and volumes of mineral constituents.
Stratigraphic Forward Simulation of the Miocene Fan Delta in the South of Albert Basin, Uganda
Authors: Xu Wei , Zhang Yingchun , Fang Lei , Jing Zhiyi , Zou Jingyun , Liu Jun 
Published: April 2019

Abstract
The Albert Basin of Uganda is located at the northern end of the western branch of the East African Rift System. It is a graben rich in oil and gas with a shallow research degree. In the south of the basin, a fan delta system controlled by the boundary fault is developed in the Miocene formation. Due to the few wells and poor quality of seismic data in this area, it is difficult to predict the spatial distribution of sedimentary reservoir sands. In this paper, sedimentary forward modeling coupled with 3D geological modeling is used to provide new ideas for reservoir prediction.
Sedimentary facies analysis is based on core description, well logs, paleontology, heavy mineral content and grain size data. Quantitative analysis of accommodation space, source supply, and sediment transport parameters can help explain the main factors that controlled the sedimentation. Milankovitch cycle method was used to establish the time scale of the basin. The simulation results were combined with 3D geological modeling to quantify the characteristics of the sand body distributions.
Sedimentary facies analysis shows that the Miocene formation in the south of Albert Basin deposited in a shallow lacustrine environment. A proximal fan delta deposition with subaqueous distributary channels was controlled by the east boundary faults. Firstly, the accommodation space was estimated according to the thickness of the stratum and the change of the ancient water depth. The source supply was estimated by the area of the project and formation thickness, and the transportation parameters were estimated according to the nonlinear transportation model based on the traction flow with a little gravity flow. Secondly, an astronomical stratigraphic framework of the Miocene strata in the south of Albert basin was established through the Milankovitch cycle stratigraphy, and it was used to restrain the process of stratigraphic forward modeling and to reproduce the sedimentary evolution process in the geological historical period. Thirdly, the stratigraphic forward modeling results were resampled into the geological model, a 3D reservoir probability distribution model is established from trend modeling to quantitatively characterize the spatial distribution of sand bodies. Finally, the sandstone distribution simulation results were transformed into quantitative control constraints for 3D geological facies modeling. Thus, the new approach significantly promotes the facies model quality and provides robust results for petrophysical property models.
Integration of stratigraphic forward modeling with 3D geological modeling can effectively solve the problem of reservoir characterization in an early stage of oilfield development through the interaction of the dual model coupling. This method has unique advantages in the reservoir research in the area with fewer data and great variation of sand.
Machine Learning for Detecting Stuck Pipe Incidents: Data Analytics and Models Evaluation
Authors: Alshaikh Abrar , Magana-Mora Arturo , Gharbi Salem Al , Al-Yami Abdullah 
Published: April 2019

Abstract
The earlier a stuck pipe incident is predicted and mitigated, the higher the chance of success in freeing the pipe or avoiding severe sticking in the first place. Time is crucial in such cases as an improper reaction to a stuck pipe incident can easily make it worse. In this work, practical machine learning, classification models were developed using real-time drilling data to automatically detect stuck pipe incidents during drilling operations and communicate the observations and alerts, sufficiently ahead of time, to the rig crew for avoidance or remediation actions to be taken.
The models use machine learning algorithms that feed on identified key drilling parameters to detect stuck pipe anomalies. The parameters used in building the system were selected based on published literature and historical data and reports of stuck pipe incidents and were analyzed and ranked to identify the ones of key influence on the accuracy of stuck pipe detection via a nonlinear relationship. The model exceptionally uses the robustness of data-based analysis along with the physics-based analysis.
The model has shown effective detection of the signs observed by experts ahead of time and has helped with providing enhanced stuck pipe detection and risk assessment. Validating and testing the model on several cases showed promising results as anomalies on simple and complex parameters were detected before or near the actual time stuck pipe incidents were reported from the rig crew. This facilitated better understanding of the underlying physics principles and provided awareness of stuck pipe occurrence.
The model improved monitoring and interpreting the drilling data streams. Beside such pipe signs, the model helped with detecting signs of other impeding problems in the downhole conditions of the wellbore, the drilling equipment, and the sensors. The model is designed to be implemented in the real-time drilling data portal to provide an alarm system for all oil and gas rigs based on the observed abnormalities. The alarm is to be populated on the real-time environment and communicated to the rig crew in a timely manner to ensure optimal results, giving them sufficient time ahead to prevent or remediate a potential stuck pipe incident.
Structure and Inhibition of the Indolizine Derivative: New Concept of High-Efficient Corrosion Inhibitors for Acidizing
Authors: Wang Renzhuo , Yang Zhen , Chen Wuhua , Wang Yefei , Ding Mingchen , Zhan Fengtao 
Published: April 2019

Abstract
Among the numerous corrosion inhibitors for acidizing, the propargyl alcohol, with great expense and high toxicity, is often added as an important synergistic component. In this work, novel indolizine derivative high-effective inhibitor for acidizing was introduced. The indolizine derivative could exhibit an excellent protection performance at a much lower concentration without the synergism of the poisonous propargyl alcohol. The two inhibitive indolizine derivatives in this paper were synthesized easily from Benzyl Quinolinium Chloride (BQC, known as the a commonly used key component of acidizing inhibitor) via 1,3-dipolar cycloaddition reaction. The indolizine derivatives were purified by the column chromatography and the structure were characterized by NMR and elementary analysis etc.
The inhibition performance of the BQC, propargyl alcohol and the indolizine derivatives in 15 wt.% HCl and 20 wt.% HCl for N80 steel was investigated by weight loss test and potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The conclusion obtained from the electrochemical tests is in accordance with the results of gravimetric test. It is amazing to notice that the derivative could exhibit a much better anti-corrosion performance than its precursor BQC and propargyl alcohol in the abserence of the poisonous propargyl alcohol.
Compared with BQC, the active adsorption sites are reinforced and strengthed in indolizine derivatives, and therefore, the inhibitor would fasten the steel surface more stronger. The firmly adsorbed inhibitors would prohibit the steel from the contact of acid. Indolizine derivative is presented as a new concept of effective acidizing inhibitor for the first time in this paper. It may offer a new method for the corrosion prevention in acidification engineering.