bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissolvable Ball as a Temporary Fluid Loss Control Device for Multilateral Wells
Authors: Mallawany I. El , Simmons Y. , Mohamed A. , Osman A. 
Published: February 2024

Abstract
Commercially available fluid loss control devices (FLCDs) require intervention or the application of pressure to reopen the well for flowback and production. In some multilateral applications, well architecture may not allow re-entry to the laterals for mechanical intervention and/or the lateral junction (for TAML ≤ 4) might not be pressure isolated to allow pressuring down the lateral. This paper discusses the use of dissolvable balls to act as a temporary FLCD and thus, eliminate the need for an intervention operation or pressuring up the junction to open it. Additionally, an overview of lab tests and field trials performed will be discussed.
Different dissolvable ball materials were tested. The test was designed to mimic the target well conditions using the target well's completion fluid, pressure and temperature. The ball that was best suited for the application was then selected for the field trial. A dedicated baffle was run as part of the lower completion inside the lateral, a few casing joints above the shallowest frac sleeve. After completion of all stimulation stages, the dissolvable ball was dropped from surface and pumped to the seat on the dedicated baffle mitigating fluid losses. No losses were observed while pulling the frac string and the multilateral (MLT) deflector out of hole, nor during upper completion installation. The dissolvable ball also did not affect the production flow during flowback operations. This was accomplished without intervention or the application of pressure through the TAML level 4 junction.
Dissolvable balls can be successfully and safely used as a FLCD in lateral branches of MLT wells. This was proven through lab testing and field trial. The main advantage of this method over commercially available FLCDs is eliminating the need for intervention or wellbore pressurization. Furthermore, this method simplifies the operation, reduces risks and provides time and cost savings. Meticulous planning and testing are key for achieving success for such applications having strict time constraints to safely proceed with the remaining operations in the completions program. In the discussed case study, the ball provided up to 17 days of safe operations without losses as the upper completions was set and tubing hanger landed. Furthermore, during flow back operations of the lateral branch, which started 18 days after setting the upper completion (35 days after ball launching), no traces of the ball were observed.
This paper describes the novel use of dissolvable balls as FLCD where traditional FLCDs are not adequate. Additionally, dissolvable balls offer simplicity as well as time and cost savings over other traditional fluid loss control devices. (El-Mallawany et al., 2022)
Machine Learning accelerated Phase Flash Calculation for CO2–Brine System considering Capillarity Effect
Authors: Aslam Billal , Tariq Zeeshan , Yan Bicheng 
Published: February 2024

Summary
The geological sequestration of carbon dioxide (CO2) has been proposed as a critical solution to mitigate climate change. Accurate prediction of CO2 solubility in brine is necessary for a better estimate of CO2 storage capacity in subsurface reservoirs. Specific Equation of State (EOS) models coupled in compositional reservoir simulators are usually used to predict the fate of dissolved CO2 over time. However, this approach can be computationally expensive, particularly if a more detailed physics description is used, such as capillarity, which is important in describing phase behavior in the cap-rock layers. To address this issue, a Machine Learning (ML) based approach is used to generate a proxy from high-fidelity physics simulations describing CO2-brine phase behavior. First, Peng-Robinson EOS, coupled with Duan & Sun model are used to generate approximately 5000 samples of CO2 solubility calculation dataset for ML model training. Several ML models such as Random Forest (RF), Extreme Gradient Boosting (XGBoost), and Artificial Neural Network (ANN) are then trained and compared to predict phase split calculation result and CO2 solubility. Potential ML model is then optimized by hyper-parameter tuning to increase prediction accuracy. Sensitivity analysis from the trained model was performed to evaluate the behavior of model prediction. The trained DNN model shows promising potential to accelerate Pressure-Volume-Temperature (PVT) and solubility calculations, with a test case showing approximately a 210 times speedup with an Average Absolute Percentage Error (AAPE) of less than 0.117% compared to the EOS calculation.
Representative Elementary Volume as Key Parameters to Improve Grid Stability on Multi-Point Statistic Based Reservoir Models
Authors: Budiman Ose , Azhar Allende G. A. , Setyadi Abdul Latif 
Published: February 2024

Abstract
Reservoir modelling plays a significant role in the investigation of reservoir heterogeneity related to the distribution of reservoir zones and lateral and vertical variations in geological and petrophysical properties of the reservoirs. Data and information derived from the core, well logs, and seismic could be used for facies and petrophysical modelling of these reservoirs. How to organize the data, how to apply the limited spatial offered by the data, and how to develop a comprehensive reservoir model by using only a few points of data are all different problems when using this data as the input for reservoir modelling. Using the Multi Point Statistics Method (MPS) to build the facies as similarly as possible to the geological feature is one of the best ways for modelling the facies. Therefore, the level of uncertainty could be reduced. However, the training image used to build the facies model must be accurate and precise. It is essential to gain as much geological insight as possible from the well logs, seismic, and core data before translated into the training image as a conceptual model. The data input could be optimized using modern tools and techniques, leading to excellent outcomes. This study discussed and dive into the various ways in which the MPS technique can be improved, such as in terms of grid stability, error reduction, well logs’ correlation to the training image, and minimize the uncertainty. The best and most effective techniques to portray a reservoir with good quality grid without scarifying the detail were determined by using the Representative Elementary Volume (REV) as the key parameter to determine layering and zoning. The result showed less discrepancy between the model and the well logs’ data, more stable grid, and will expect to be impacting the simulation progress by lowering the running time. Proper utilization of training images is also required for the geological feature to accurately record observations. It is shown that using REV for zoning and layering will improve the efficiency and accuracy of the 3D facies model.
Seismic Attributes Contribution for CCUS Monitoring Projects
Authors: Amrouche M. 
Published: February 2024

Abstract
Seismic attributes are mathematical representations of various physical properties of the subsurface reservoir in seismic data, such as seismic amplitude, phase, frequency, and velocities. They are widely used in modern seismic interpretation workflows and can bring additional value at different stages of Carbon Capture, Utilization, and Storage (CCUS) projects, as they provide an additional insight that cannot usually be achieved in the original seismic data. Seismic attributes can be used to identify potential CO2 storage layers, monitor the behavior of the CO2 plume during injection and migration and model or extract the exiting volumes from the data.
In this study we assess the applicability of some selected seismic attributes routinely used in seismic interpretation, to enhance CCUS interpretative workflows such as stored carbon monitoring, migration path and volume extraction. We used the Sleipner Carbon Capture Storage (CCS) project 4D seismic dataset (Norway) to demonstrate the ability of structural and stratigraphic attributes to enhance mapping and monitoring of the injected CO2 plume through the years. Results from our experiments shows that structural seismic attributes can help to enhance the resolution of the original seismic data and obtain higher resolution imaging of the injected plume, by comparing changes in seismic amplitudes at the different stages of the injection. Stratigraphic attributes helped to improve the plume signature through the different stages of injection and extract the final shape of the injected carbon from seismic data as discrete geobodies. Interpretative Workflows using seismic attributes discussed in our paper can be replicated to other CCUS projects, and help to understand the injected carbon behavior, optimize injection strategies and ensure a safer and more effective storage process.
First LWD NMR Acquisition in 8.5-inch Extended Reach Well
Authors: Soma Ahmed M , Manuaba Ida Bagus Gede Hermawan , Hursan Gabor G , Steene Marie Van 
Published: February 2024

Abstract
Logging-While-Drilling (LWD) nuclear magnetic resonance (NMR) data was acquired in an extended reach well targeting a carbonate formation to obtain rock quality and permeability data. The challenge was to minimize lateral motion that could affect the NMR data quality.
Pre-job modeling was performed to evaluate the bottom-hole-assembly (BHA) stability and optimize the drilling parameters. A novel system using downhole drilling mechanics measurements while drilling was set up to evaluate the effect of drilling mechanics on the NMR sensor while drilling. Several intervals were relogged to compare the drill pass data and the reaming data, to confirm the absence of lateral motion affecting the data.
The LWD NMR data was acquired while drilling over just under 4000 ft. The well experienced a build of inclination to optimize reservoir contact. The downhole drilling mechanics flag showed a medium risk of lateral motion, also highlighting the absence of stick and slip while drilling. The LWD NMR drill pass and ream pass data compared well, confirming the absence of significant lateral motion effect on the NMR sensor while drilling. The relog passes experienced more stick and slip than the drill passes, due to the low rotations per minute (RPM) used during ream passes acquisition. The NMR highlighted a good relationship between porosity and pore size distribution in both reservoir sections.
For the first time in the region, LWD NMR data is acquired in the 8.5-inch section in an extended reach well with good quality NMR data.
Using Pressure Transient Analysis as an Effective Surveillance Technique to Locate the Remaining Oil in a Sandstone Heavy Oil Reservoir Under Water-Flood
Authors: Almahrouqi A. , Govinda P. , McCaslin J. 
Published: February 2024

Abstract
This paper aims to present a case study of the results of several falloff surveys done in relatively heavy oil field. It focuses on interpreting pressure transient analysis (PTA) in a pattern-developed, water-flooded field. The objective of the paper is to demonstrate that by utilizing a pressure falloff survey, it is feasible to detect the change of mobility (K Kr/µ) away from the water injector, resulting from the transition to higher oil saturation.
In subject field, the oil exhibits a viscosity that is 90 times higher than that of water. In principle, this significant contrast can be identified through the pressure response, indicated by a shift in mobility away from the well. The geology around the well, seismic interpretation and well history are critical in understanding the boundary responses in the PTA.
A comparison between 3 falloff surveys will be discussed: A newly drilled injector, a one-year injector and a five-years injector.
New injector: A pressure falloff with a simple response can be seen where the early-time region is dominated by skin. Followed by radial flow and no boundary response. Interestingly, the mobility obtained from the radial flow period is very low suggesting that the formation is predominantly saturated with oil. One-year injector: The radial flow region is small, however, unlike the first injector, the mobility in the initial radial flow is higher compared to first injector however, it reduces after 7 meters inside the reservoir (Ri) which then stabilize at 1/5th of the original mobility. Five-years injector: Similar to case 2, the radial flow region stabilizes at a mobility similar to the expected from petrophysical analysis. However, after a distance of 45m, the mobility reduces to 1/6th of the original. This indicates an increase in oil saturation beyond the 45m mark, away from the injector.
After considering all potential boundaries that could result in this response, the most reasonable and likely scenario is a change in fluid saturation from water to oil away from the injector. This is supported by the good correlation found between cumulative water injected and the distance at which the mobility reduces in PTA. This finding suggests that falloff can be utilized to track the advancement of the waterfront, particularly when a significant mobility contrast exists between the fluids. This also means that an average oil saturation away from the injector could be approximated enabling the detection of un-swept areas in the field.
Given the significant viscosity contrast between water and oil, the Falloff survey, when integrated with other data sources, can be employed as a cost-effective and straightforward surveillance tool to identify the waterflooded area surrounding the injector and track waterfront progress.
A Streamline Based Lagrangain Method to Investigate Two-Phase Flow in Hydrocarbon Recovery
Authors: Ahammad M. J. , Rahman M. Azizur , Alam J. M. 
Published: February 2024

Abstract
The study of miscible flow is an important topic in the field of petroleum science and engineering. The miscible displacement of hydrocarbon-like oil by a solvent such as carbon dioxide helps to enhance the recovery of the hydrocarbon. The use of CO2 helps to reduce the viscosity of resident fluids like oil, In addition, the use of CO2 would reduce its accumulation in the atmosphere to help a green environment. The production of hydrocarbons in the secondary or tertiary phase follows the mostly miscible flow. The Computational Fluid Dynamics (CFD) simulations can help with better understanding enchanch oil recovery in the two-phase flow system. The traditional simulations of such flow suffer numerical artifacts due to the appropriate methods. We present a generalized CFD model for studying the transient methodology for momentum transfer. We investigate an upscaling approach to resolve the small-scale features of miscible flow in a porous medium. A streamline-based Lagrangian model is developed to study the displacement of oil by CO2 with sufficient accuracy and near-optimal computational cost.
How the Memory Multidetector Pulse Neutron Logging Helped to Achieve a High-Quality Results While Reducing the Costs – Case Studies in Malaysia
Authors: Loo S. , Willick J. , Pemper R. , Mekic N. , Khalid K. Binti , Johare D. , Goh A. , Huong C. 
Published: February 2024

Abstract
Managing reservoir performance and monitoring is an ever-increasing challenge in offshore brown field environments where cost optimization becomes more critical. The limitation of wireline accessibility on the wellsite tends to evaluate an opportunity to run the memory Multidetector Pulsed Neutron (MDPN) logging technology allowing a cost-effective and conveyance-unrestrained option for reservoir evaluation.
The typical wireline conveyed service of a pulsed neutron technology with a five-detector array has proven to be reliable in Field A, offshore Malaysia. It was successfully run on across gas and oil intervals behind multi-tubing completions and complex downhole conditions. The utilization of slickline conveyance on memory allows the reduction on well-site manpower, spacing and equipment. Slickline operation requires the addition of a battery pack with an integrated tool controller, memory module and safety sub to the standard logging suite. Extensive laboratory testing, simulation and well tests were conducted to assure reliability of the memory MDPN system to deliver wireline-equivalent results.
Memory MDPN with slickline offers the ability to capture critical Carbon/Oxygen and advanced gas measurements for oil and gas saturation analysis as well as capture the fluid movements using a time-lapse reservoir evaluation. Interpretation of memory MDPN data delivered information on fluid contact movement within the complex multi-stacked siliciclastic reservoirs. Results were validated by correlation with production history of the subject wells and corroborated with past pulsed neutron results from nearby wells. The MDPN technology has proven beneficial for complex wells with its advantages of a large detector array, integrated response characterization modeling, and wireline-equivalent data. As an added advantage, the reduced operational footprint saved the operation ~54% in cost compared to a standard wireline operation since wireline skid unit and crane were not required. Additionally, operational simplification, easier mobilization and streamlined operations lead to the reduction of personnel risk exposure, energy, emissions, and waste.
Effective reservoir evaluation in brown fields remains an important activity for operators while maximizing the potential production from a reservoir. With the introduction of a memory pulsed neutron logging system, operators can now perform cased hole evaluation in a more efficient and cost-effective manner, achieving similar data quality to conventional wireline logging even in complex logging environments.
One MrSET Test Example in the Complex Underground Structure Area
Authors: FuHao JIANG , YuDong NI , WuHai YIN , Di WU , NaiJian WANG , XingGang LIU , ZhiHui YAN , WenJian LI , XiChang HOU , MingYi HAN , Jie SHENG 
Published: February 2024

Abstract
Multi-rate seismic exploration technique (MrSET), which is based on the pre-stack migration imaging (PreMI) theory, has achieved appreciated result in the field test in a basin in West China, where the surface terrain is simple and the underground structures are not very complex relatively. In order to further verify the applicability of the technique, while make the method and the technique more perfect, a swath 3D field test is carried out in another basin in West China, where underground structures are complex relatively. Identical shooting parameters are applied in the test to compare the imaging effects of the data acquired at the same receiver points of the same line using two different node layouts (the conventional regular layout and the MrSET layout designed based on the PreMI theory). The test results show that the imaging of data acquired using the MrSET layout is better than that of the data acquired using the conventional regular layout method.
Numerical Simulation Study on Enhanced Efficiency of Geological CO2 Storage with Nanoparticle
Authors: Kumasaka J. , Sugai Y. , Ishibashi F. 
Published: February 2024

Abstract
Carbon dioxide (CO2) geological storage has a large potential to achieve a net-zero target of CO2 emissions. CO2 injected into the storage formation typically becomes a super-critical state under the underground temperature and pressure conditions. The injected super-critical CO2 (scCO2) tends to migrate upwards within the reservoir due to its lower density compared to the formation brine even though the density of scCO2 is quite higher than that of gaseous phase CO2. Moreover, injected CO2 is affected by not only the gravity segregation but also the viscous fingering. These phenomena are expected to cause poor storage efficiency in carbon storage projects. In this study, we investigated the potential of adding common metal oxide nanoparticles to scCO2 to improve the storage efficiency utilizing the properties of scCO2 as a solvent under subsurface conditions.
This paper presents the pseudo-fluid modeling of scCO2 containing nanoparticles and the results of numerical simulation considering the effects of nanoparticle types and concentrations on the CO2 storage efficiency. In particular, the effect of density alteration on CO2 storage efficiency was investigated in this study. Some pseudo-fluid models of scCO2 containing four types of nanoparticles, such as aluminum oxide, silicon dioxide, titanium oxide, and zinc oxide with different concentration were created, respectively. Furthermore, numerical simulations of scCO2 injection with and without nanoparticles were performed using a two-dimensional radially symmetric model. The results from this work showed the migration of CO2 to the upper part of the formation was suppressed and the storage of CO2 in the lower part of the formation was promoted when scCO2 was injected with nanoparticles. Furthermore, CO2 breakthrough time was delayed several months or years and total breakthrough quantities were also decreased as the density and concentration of nanoparticles in scCO2 became higher in the case of installing an imaginary production well for pressure control. These results suggest that the injection of nanoparticle-dispersed CO2 improves the storage efficiency of CO2 geological storage compared to the injection of CO2 alone. Furthermore, this study showed that the concept has possibility of improving the safety of CO2 geological storage, which may play an important role when considering the long-term CO2 sequestration as well.
Optimization of Injection Scheme for China's First Carbon Storage Project in Offshore Deep Saline Aquifer
Authors: Wang Zhiqiang , Li Hangyu , Liu Shuyang , Liu Junrong , Xu Jianchun , Chen Jiayu 
Published: February 2024

Abstract
Carbon capture and storage (CCS) is one potential way to mitigate the CO2 emission to atmosphere and achieve the goal the carbon neutrality all over the world. Enping 15-1 CO2 Geological Sequestration Project is China's first offshore CCS project. The injection schemes including injection well type and gas injection rate are investigated in this work. A compositional & geomechanical simulator (CMG-GEM) is applied to establish a pseudo field-scale model and design the schemes for the project. The results show that the evolution of CO2 saturation of vertical well and horizontal well are almost consistent during the injection and post-injection period, but the horizontal well has lower BHP, which is safer and could prevent the formation fracturing. In addition, the scheme of increased gas injection rate is optimal when horizontal well is used for the project as the lower BHP and more capillary trapping CO2. Therefore, the scheme of horizontal well with increased gas injection rate is recommended for the project.