bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of Shale Wettability Alteration upon Exposure to Surfactants
Authors: Alzaabi Ahmed , Adila Ahmed Sami , Rahman Md Motiur , Ali Mujahid , Keshavarz Alireza , Iglauer Stefan , Arif Muhammad 
Published: March 2023

AbstractThe development of unconventional resources such as shales has gained great popularity in the past decade. The objective of this study is to investigate the effect of surfactants on the wettability of shale rocks. In particular, we examine the influence of different concentrations of CTAB and SDBS surfactants on Eagle Ford, Wolf Camp and Mancos shale samples to determine their wettability alteration potential at the macro-scale.In this work, macro-scale contact angle (CA) measurements of the three studied shale samples were conducted at ambient conditions as a function of surfactant concentration. Additionally, rock surface imaging was conducted via Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) at the nano- and micro-scale respectively. Surface chemistry was also investigated through zeta potential and Fourier-transform infrared spectroscopy (FTIR) analysis to understand the interactions at the surfactant-mineral interface and its associated impact on wettability alteration.The results indicate that the wettability alteration potential of surfactants on shale surfaces is closely related to rock minerology, while it is a relatively weak function of surfactant concentration. The contact angle results of Eagle Ford and Wolf Camp indicate mixed-wet conditions, while Mancos indicates water-wetness. The contact angle results at high pressure show that the increase in pressure leads to contact angle increase. The results also show that zeta potential results for all shales tends to increase in magnitude as the concentration of both surfactants increase. Additionally, FTIR results indicate the presence of C-O (carboxylate group), Ca-C, and Si-O bonds on the surfactant-treated surfaces at different extent. Finally, surface topography images revealed that Eagles ford and Wolf Camp have a relatively higher surface roughness compared to Mancos.This study aims to develop scientific understanding of the different shale compositions and surfactant wettability alteration of shale rocks from a micro-scale perspective.
Shale Oil Fracturing Optimization with an Integrated Workflow in Daqing Oilfield, Northeast China
Authors: Xiang Chuangang , Fu Zhiguo , Zhuang Xiangqi , Gao Bei , Chen Yingru 
Published: March 2023

AbstractIn order to improve the production of Gulong shale oil from well stimulation, a Geoengineering integrated model was established through integration of geological modeling, geomechanics modeling, fracturing modeling and reservoir simulation from QH working pad in Daqing oilfield, Northeast China. Based on integrated modeling workflow and study, key stimulation parameters such as stage interval, clusters of stage, frac liquid volume and proppant volume, well spacing were quantitatively optimized. Optimization study indicated 70-80m stage interval, 10m cluster interval (7 clusters per stage), frac volume 1,400 m3 per stage, proppant volume 140 m3 per stage are best parameters in QH pad and 400 m well spacing staggering across zones are best well pattern to QH pad. The study results are of great significance to the realization of large-scale rapid production increase and profitable development for Gulong shale oil reservoirs.
Engineered Bit Design with New Cutter Technology Improved Drilling Efficiency in Abrasive Sandstone in China Ordos Basin
Authors: Liu Yongjun , Li Jinsong , Lin Dong , Sun Jiacai , Luo Lei , Chen Guiyang , Li Peng , Ding Peng , Chen Zhiqiang , Xia Yang , Xiao Rui 
Published: March 2023

AbstractDual lateral horizontal wells were drilled for China Changbei tight gas development in Ordos basin. The horizontal 8 ½" hole section is the most challenge part for efficient well construction due to the hardness and abrasiveness of the consolidated sandstone rocks. Optimized drilling performance requires the matching of appropriate drill bit technology to an application for the formation to be drilled, which can be an engineering challenge. Various types of drill bits, including TCI, PDC and Hybrid type bits are used in Changbei for continuous performance improvement.The 8 ½" hole section consists of hard and abrasive sandstone, interbedded claystone, and conglomerates. Most drill bits suffered short runs due to severe wear in the outer region of the bit including Gauge and Shoulder area, even lost cones for TCI and Hybrid bits.With collaborations from operators and bit vendors, based on dull review and data analysis, a new type of PDC bit was designed with advanced cutter technology. The new design was developed to increase ROP and run length, avoiding unnecessary trips in the challenging formations and improved the drilling efficiency.The new designed PDC bit adopted short profile design, reversed circle cutter placement pattern, balanced the aggressiveness and durability with backup cutters and DOC control. PDC cutters was used for passive gauge protection to overcome the wear out due to formation abrasion.The field trials were very successful. The new designed PDC bit improved 30% on ROP and 10% on footage per bit run than offset Hybrid bits. Moreover, the new designed PDC bit eliminated lost cone risks of TCI and Hybrid bits, which was happened a couple of times in Changbei and caused tremendous NPTs for fishing and sidetracks.This article will describe the bit performance improvement journey of Changbei tight gas field. Even with a long period of time staying on plateau, step changes still possible with new technology deployment and continuous improvement mindset.
Evaluation of Over-Pressured Gas Reservoirs: Reserves Estimation to Production Performance - A Case Study
Authors: Muneez Iqbal , Saad Mehmood , Muhammad Hasnain , Qazi Munawar , Jahangeer Zafar 
Published: March 2023

AbstractGeo-pressured reservoirs are challenging in terms of in-place estimation and maintaining sustained production. Estimation of Gas Initially In-place (GIIP) using P/z from early data shows incorrect estimation and resulted in over-predicting GIIP. Typically, over-pressure gas reservoirs show downward curvature in P/z plot early or slightly delayed depending upon the pool limit and the degree of overpressure. A rapid decline in production also observed in the over-pressured gas reservoirs resulted in low hydrocarbon recoveries. This paper aims for correct GIIP estimation in over pressured gas reservoirs and to better manage and maximize recoveries from the Field.Based on available pressure and production data, two approaches were used in order to estimate the GIIP of the Field. (1) Conventional P/z by using Hammerlindl method (2) Developed analytical model by incorporating rock compressibility value from the Geomechanical SCAL study. The calculation of GIIP from both the methods are somewhat in close agreement as the vital factor of rock compressibility was introduced in GIIP estimation, to cater for the effect of reducing porosity as the pressure drops, resulting in changing storage capacity of the rock. Additionally, consecutive pressure Build-up data history showed reduction in permeability with the time from 9 mD to 0.4 mD. This change in permeability is caused by near wellbore overburden stress increase resulting in rock expansion which in turn reduces/closes pore throats. This manifest as an apparently damaged region causing lower rates and poor recoveries. In this scenario the well would be shut-in at higher abandonment conditions.Basic geo-mechanical parameter of rock compressibility plays an important role in reserves estimation for over-pressured reservoirs. Previous literature and our evaluation suggest that optimum production strategies for such reservoirs are: (1) To produce at lower rates at which drawdown is less than half of prevailing pore pressures. (2) Drill more wells to sustained production while producing at lower rates. Both strategies under optimum conditions would result in uniform depletion and better recoveries.Production performance with time, rapidly decreases as permeabilities reduce due to near wellbore stress sensitive region caused by larger drawdown so a controlled drawdown is recommended.
A Look Ahead to the Future of Surfactant Flooding EOR in Carbonate Reservoirs under Harsh Conditions of High Temperature and High Salinity
Authors: Adel Imad A. , Hassan Anas Mohammed , Al-Shalabi Emad W. , AlAmeri Waleed 
Published: March 2023

AbstractCarbonate reservoirs under harsh conditions of high temperature and high salinity (HTHS) have been exploited through primary and secondary recovery methods. This leaves substantial untapped reserves that require the use of enhanced oil recovery (EOR) techniques. Chemical EOR (CEOR) applications, particularly surfactants, in improving recovery under these HTHS conditions are challenging. Developing suitable surfactants that withstand these conditions can improve water imbibition into the low permeability rock matrix, alter the rock wettability, and significantly lower the interfacial tension. The assessment and evaluation of potential surfactants as EOR agents is of great interest and has a strategic role in unlocking further reserves from the vast accumulations of light oil in low permeability carbonates. However, the implementation of surfactants under these conditions faces various challenges, such as stability, compatibility, and high retention values, which need to be overcome for successful applications. This paper provides comparative review analyses and critical discussions on the recent developments to overcome these obstacles and the promising potential for successful surfactant flooding implementations in carbonates.Surfactant selection is a complicated process, where the surfactant formulation needs to pass several screening techniques. In this paper, limitations, requirements, and aspects affecting the IFT, microemulsion phase behavior, and retention were thoroughly reviewed. Surfactant retention remains the primary factor limiting the implementation of surfactants in carbonate reservoirs under harsh conditions. Nevertheless, recent laboratory studies (screening and corefloods) showed that chemical formulations, including new classes of surfactants with suitable solvents and alkalis, showed excellent performance with minimal retention values under these conditions. Field studies and pilots of surfactant EOR in carbonate reservoirs were also reviewed, highlighting procedures, achievements, challenges, and the way forward to successful applications. A list of recommendations and conclusions is provided at the end of the study based on the literature and our expertise in this area. Surfactant EOR has long been considered impractical in the high temperature and high salinity conditions present in carbonate reservoirs. This study reviews the latest developments and positive outcomes that change this perception and aid in unlocking these reserves. The study is also considered a guide to starting surfactant flooding projects in carbonates under harsh conditions in the Middle East region and elsewhere.
Reservoir Modelling of Nanoparticle-Assisted Foam to Optimize Gas Injection in an Unconsolidated Heavy Oilfield
Authors: Bello Ayomikun , Dorhjie Desmond Batsa , Ivanova Anastasia , Cheremisin Alexander , Cheremisin Alexey 
Published: March 2023

AbstractFoam can be used as an enhanced oil recovery (EOR) technique because it can reduce gas channeling and gravity override during gas EOR operations by lowering gas mobility, which will bring about an increase in oil recovery factor. An integrated method for numerically simulating foam assisted by nanoparticles for EOR in a heavy oilfield is presented in this paper. The extent to which the gas EOR optimization techniques can lower gas breakthrough while boosting oil recovery was investigated through a series of numerical simulations. The aim of this study is to model foam flooding with nanofoams as an EOR technique that combines the oil recovery mechanism of foam flooding with that of nanoparticles. The interfacial properties contributed to the injection fluid served as a representation of the modeling of nanoparticles in the foam liquid. Our findings demonstrated that the recovery factor is higher during the injection of nanofoams than in water and gas flooding. In fact, for both nitrogen and CO2, the recovery factor of foam enhanced by nanoparticles was nearly twice as high as that of gas injection. Foam injection is more effective and productive than WAG and gas injection, which shows that it is the best EOR technique for the model utilized in this study. The simulation of the optimization techniques carried out will aid in the development of future development processes in this field.
IFT Reduction Negatively Impacts Oil Recovery When Wettability Alteration Happens
Authors: Deng Xiao , Patil Shirish , Al Shehri Dhafer , Kamal Muhammad Shahzad , Shakil Syed Muhammad , Zhou Xianmin , Mahmoud Mohamed , Al Shalabi Emad Walid , Hassan Anas 
Published: March 2023

AbstractInterfacial tension (IFT) reduction and wettability alteration (WA) are the two most important mechanisms for chemical EOR. When two mechanisms are combined, however, the relative contribution of each mechanism is hard to determine. Researchers have obtained different, sometimes conflicting, conclusions. Numerical simulation studies usually suggest that, when WA happens, IFT should not be reduced. In this work, we investigated experimentally how IFT reduction impacts oil recovery when wettability alteration happens. To answer this question, this study tests the oil recovery potential of novel zwitterionic surfactants (ZS) and Gemini surfactants (GS) for oil-wet carbonate rock. A chelating agent was added to alter the properties of the surfactants to get comparable WA performance but different IFT.The surfactants used in this study were a zwitterionic surfactant Erucamidopropyl Sulfobetaine, and a locally synthesized amino-amine-based cationic Gemini surfactant. Diethylenetriamene pentaacetate (DTPA) chelating agent was used. Indiana limestone was selected to represent carbonate rocks. The spinning drop method was applied in IFT measurements. Static contact angle under room conditions and reservoir conditions was conducted to evaluate the WA performance of studied materials. Spontaneous imbibition tests were conducted using oil-aged limestone core plugs. By comparing the IFT reduction, WA, and oil recovery, the relative importance of the mechanism was reflected.Results show that investigated zwitterionic surfactant reduces IFT more than Gemini surfactant. However, Gemini surfactant showed much better WA performance than zwitterionic surfactant. When DTPA was added to zwitterionic surfactant, the wettability alteration performance of zwitterionic surfactant was improved. The mixture of DTPA and zwitterionic surfactant (DTPA/ZS) showed comparable wettability performance compared to DTPA and Gemini surfactant (DTPA/GS). However, the IFT value of DTPA/ZS is much lower compared to DTPA/GS. In spontaneous imbibition tests, the mixture of DTPA/ZS recovered oil much slower than the mixture of DTPA/GS. This shows that when wettability alteration happens, reducing IFT to the ultralow condition has a negative effect on oil recovery. This is because when wettability is altered to water-wet conditions, the capillary force becomes a driving force that helps oil production. Reducing IFT will reduce the magnitude of capillary force, thus negatively impacting the oil recovery rate.This study shows that for the spontaneous imbibition process in low permeability carbonate rock, IFT reduction negatively impacts the oil recovery when the rock wettability is altered from oil-wet to water-wet.
A High Molecular Polymer LCM to Cure Severe Losses While Drilling Shallow Aquifers in UAE
Authors: Hamdan Tariq , Saraji Raymond , Yang Tao , Al-Rahma Rahma , Abdullah Dalia , Al Nuaimi Mouza , Zhou Changjiang , Hu Xuezhi , Cheng Yi , Guo Yongjun , Zhang Xinmin 
Published: March 2023

AbstractToday, well durations are relatively longer due to several factors. Some of these include but not limited to intermediate section down hole losses. Therefore, there is an opportunity to explore possible ways to reduce well duration and cost while meeting all business objectives with 100% HSE. Dammam, U.E.R, and Simsima are karsts-prone carbonate aquifers widely developed across UAE. As formation pressures are depleted, severe to total losses is increasingly occurred during drilling through these shallow aquifers. Conventional loss curing agents are often failed, especially in Simsima, because of their inability to set in such complex and large fractures and caverns.ZND gel is a water-soluble high molecular polymer, which will automatically set and seal the space after being pumped into loss channels. As hardly be diluted by any formation fluid, a gel slug is formed to isolate drilling fluids and consolidate agent from being washed away into loss zones. In this study, we present a composite solution of ZND gel and Cement applied in onshore Abu Dhabi, which effectively mitigated the total losses encountered in Simsima.
Innovative Management Reporting for Real Time Dynamic Decision Making
Authors: Samsuddin Khairul Nazri 
Published: March 2023

Abstract
This manuscript will be consisting of 2 main sections. 1st section which directly addresses the title of this article i.e. innovative management reporting for real time dynamic decision making. The 2nd section of the manuscript will touch 4 frequently asked questions which will support the concept and understanding of the title.
Meta Learning Using Deep N-BEATS Model for Production Forecasting with Limited History
Authors: Al-Ali Zainab Al-Ali Hussain , Horne Roland 
Published: March 2023

AbstractFluid rate quantification is important for field development and well planning. Existing physical and data-driven models require a copious amount of reservoir information and history to improve the capability of prediction. In this paper, we introduce a new approach of using a deep meta learning approach using Neural Basis Expansion Analysis for Interpretable Time Series Forecasting (N-BEATS) model to forecast the oil rate, eliminating the need of large historical training datasets to overcome the limitation of conventional models.Two deep learning models, the Long- Short-Term Memory (LSTM) and N-BEATS, were used to forecast the oil rate data of two wells from Norne Field in Norway. The historical bottom hole pressure data with only 500 data points were used as input in the LSTM model. To overcome the dataset limitation, we developed and tested a pretrained N-BEATS transfer model. The N-BEATS model was initially trained on a large and heterogeneous dataset, widely known as the M4 series, with an excess of 100,000 time series. This pretrained model was then used to forecast the oil rates using a meta learning approach.It was challenging to fit the LSTM model, as it demanded complex hyperparameter tuning and grid search to solve this nonlinear multivariate time-series forecasting problem. Even after we tuned the model's parameters, the model could not generalize the testing data attributed to the limited and small dataset available during training. Our work showed that the newly proposed N-BEATS meta learning model was better able to capture the dynamic time series features from the M4 dataset and transfer the learned knowledge. The N-BEATS approach was able to forecast oil rates in Norne field for both wells without supplying the model with any features or input variables, such as the reservoir pressure. The Mean Squared Error (MSE) was used as an evaluation metric to benchmark the prediction results from both models. The results clearly demonstrated that the N-BEATS meta learning approach outperformed the LSTM model performance when comparing the difference between the model forecast and actual data. We concluded that using the pretrained N-BEATS model overcomes the previous disadvantages in LSTMs model requiring feature selection and abundant training history.To the best of our knowledge, our work presents a novel approach of using N-BEATS meta learning model for oil rate forecasting without any prior knowledge of the field. Most previous machine and deep learning attempts were based mainly on deriving predictions from an abundant historical field data. This research showed promising results using meta learning and N-BEATS model in the petroleum industry, especially for new or green fields with limited historical data.
Radial and Huff-n-Puff Gas Injection on Microfluidic Chips
Authors: Pereponov Dmitrii , Tarkhov Michael , Rykov Alexander , Filipov Ivan , Zenova Elena , Cheremisin Alexey , Shilov Evgeny 
Published: March 2023

AbstractMost of the reservoirs today are mature, and traditional waterflooding is not enough for the effective development of oil formations. One of the ways to significantly increase production efficiency for deep, low permeable reservoirs is gas EOR (enhanced oil recovery) methods. This paper presents a method for screening and increasing efficiency of gas EOR methods based on microfluidic studies and for studying the influence of various factors on the oil displacement process. Such technology can be used on par with traditional core flooding tests, reducing time, cost, and the amount of needed fluid. The porous structure was realized as a silicon-glass microchip that can withstand high pressure and temperature close to the reservoir conditions. For the tests, n-decane was chosen as a model oil phase, while nitrogen was used along with carbon dioxide for screening. On the microchips, several tests were done that proved the approach's effectiveness for screening gases before field application. The most effective for carbon dioxide occurred miscible displacement, resulting in the almost complete displacement of n-decane. Additionally, when comparing tests with the same system pressure but a different pressure drop, a more considerable drop led to a higher oil recovery coefficient. Since the conventional nitrogen injection resulted in an insignificant displacement coefficient even after an increase in differential pressure, it was decided to use this agent for the huff-n-puff injection experiment. The test led to the raising of the sweep efficiency coefficient by two times. Thus, an experimental procedure and a unique microchip geometry with the radial homogenous porous structure were developed, allowing tests to be performed for both conventional gas flooding imitating a five-spot pattern and huff-n-puff gas injection.