bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Intelligent Inversion Method for Complex Fractures Using Ensemble Neural Network
Authors: Sun Shibo , Wang Wendong , Su Yuliang , Deng Yuxuan , Li Haoyu 
Published: November 2023

Abstract
Proper characterization of fractures is critical for evaluating the effectiveness of fracturing jobs and optimizing well performance in unconventional reservoirs, geothermal energy production, and other areas. However, accurately determining the size, shape, and orientation of these fractures solely from microseismic events is challenging due to weak signals and noise. To address this challenge, this study proposes a novel workflow that directly builds accurate fracture models from microseismic events using the DBSCAN clustering algorithm and ensemble neural network. The first step is to filter the noise in microseismic events using the DBSCAN clustering algorithm. Next, a 3D planar equation is employed to construct the fracture plane. Based on the results of this step, reservoir simulations are performed iteratively using an embedded discrete fracture model (EDFM) and proxy. Multiple representation models are obtained to capture calibration uncertainty and enable subsequent studies of long-term well performance, such as history matching for production. Finally, an integrated neural network incorporating the ES-MDA history auto-fitting algorithm is utilized to find the most appropriate fracture model for matching field production data through iterative processes. The developed complex fracture inversion method was implemented on a representative shale gas horizontal well. The results demonstrate that the DBSCAN clustering algorithm effectively reduces noise in microseismic activity and ensures the accuracy of fracture geometry. A large number of different fracture models can be quickly generated by the proxy model to capture calibration uncertainty. An integrated neural network with a history auto-fitting algorithm is utilized to optimize the fracture model and identify the optimal solution. The fracture models constructed using this method exhibit fracture half-lengths and fracture heights that are 20%-40% smaller than those estimated by microseismic monitoring. Furthermore, the high level of historical fit for this horizontal well indicates that the complex fracture model is realistic for the mine site. This study introduces a new approach to building a complex fracture network. By using microseismic data, and implementing an automatic history matching system, this method provides a practical solution. The proposed workflow shows a significant improvement in both the accuracy of fracture network prediction and computational efficiency compared to traditional fracture inversion methods, which are often plagued by high multi-solution, high computational cost, and difficulties with convergence.
Unlocking Unconventional Reservoir Potential in Intrusive Igneous Rock (Tempino Sill) in Jambi Asset, Central Sumatra, Indonesia
Authors: Alfajri Reza , Haribowo Andri , Herusakti Adhi , Rahadian Reza , Sipahutar Herbert , Sihombing Giovanno Leonardo 
Published: November 2023

Abstract
The Tempino Structure is one of the brownfield structures located in South Sumatra Basin, Jambi Sub-Basin, Jambi. It has been producing hydrocarbons since the 1920s, with the main reservoir consisting of multiple reservoir layers from the Air Benakat and Gumai Formations. The reservoir has contributed 900 BOPD of Jambi Field oil production. Although field development is focused on its shallow reservoir, there is also an urgent need to find a new gas source to fuel surrounding structures or major projects in this field. Therefore, there is a plan to develop a deeper reservoir known as intrusive igneous rock, Tempino Sill.
Sill often occurs in an intrusion between older sediment, parallel to the bedding of the surrounding rocks, and may have specific vertical to horizontal dipping orientation. The occurrence of this igneous rock was confirmed by log data from well T-176 in 1976 as the deepest drilling well in Tempino. T-176 open hole log and mud log data show unique lithology of two bodies of sill which indicated as granitic to dioritic rock with weakly calcareous altered material and fracture occurrence. These sill bodies, marked as Sill-1 and Sill-2 reservoir, have gross thicknesses of 50 to 70 meters, respectively, are characterized by high resistivity, and are separated by a 100 meter Gumai shale interval. They have been proven to produce gas at a rate of approximately 6 MMSCFD. Well log and 3D seismic data, albeit with limitations, have been analyzed to evaluate the structure and distribution of the unconventional igneous rock. Furthermore, an analogous model in Eastern Java sill was used to constraint lateral distribution of this reservoir, which resulted in 10 BSCF gas potential in Tempino. Based on these subsurface evaluations, and mechanical problems of well T-176, it is planned to drill a twin well named T-176TW to prove the potential of this sill reservoir.
The execution of Well T-176TW is expected to produce 1.6 MMSCFD plateau gas for seven years. This gas production will play a significant role in the Tempino project. The scope for this project includes drilling seven injectors and four producers, along with developing a water treatment injection plant. The project is prospected to contribute 8 MMSTB incremental oil reserves or 2.85% increase in ultimate recovery factor. Utilizing Well T-176TW gas reduces CAPEX by 59% and boosts the economical position of this project when compared to buying gas from an external source.
Besides having an important role in the Tempino project, the discovery of a new unconventional reservoir in Tempino Sill also opens a new window of opportunity in terms of structure development. This unique characteristic of Tempino Sill could be mirrored in nearby structure to unlock similar potential of unconventional reservoirs in Jambi, Central Sumatra, Indonesia.
Research and Practice on Efficient Development of Chang7 Shale Reservoir in Ordos Basin
Authors: Ma Hong , Yu Huijuan , Dang Yongchao , Liang Xiaowei , Huang Zhanwei , Yang Yunchun , Zhang Yuliang , Dang Chenyue , Wang Chenyang 
Published: November 2023

Abstract
The Ordos basin is the second largest basin in China, which is well known for its "three low" – low perm, low pressure, and low abundance (volume in place per km2). Deposited in deep-water lacustrine environment, Chang7 shale oil formation in Ordos basin has huge resources in place, which is expected to be the most important strategical succession resources in China. Through nearly 10 years of research and practice, Ordos shale oil has achieved scale-effective development and has established several million-ton production demonstration sites. Horizontal well dense-cluster volumetric fracturing, being one of the effective technologies applied in Ordos Chang7 shale oil development, its concept is closely related to fractured horizontal length optimization. During "fracturing-soaking-production" practices, optimal soak-in time, flowback control, and production management system have been established. This paper demonstrates the optimization process and the best practices on these aspects.
The method used to assess the optimal horizontal section is to study the relationship between the length of the horizontal section and the well production as well as the investment of a single horizontal well, which is based on the geological characteristics of the reservoir. The process to evaluate the best soaking period include laboratory seepage-imbibition measurement through NMR technology, the numerical simulation and onsite oil-water displacement process observation of the real production. In addition, a reasonable flowback strategy is established based on production data and problems caused by proppant production. The "flow-saturation pressure ratio", which is the ratio of flowing wellhead pressure of the single well over reservoir saturation pressure, is a key concept applied to optimize flowback rate and production control. During production stage, the production rate per unit horizontal length is optimized by water cut and flow-saturation pressure ratio.
Preliminary Investigation on Impacts of Temperature, Pressure, Viscosity, and Solubility on Expansion of CO2-Based Foamy Bitumen
Authors: Meakh S. , Sugai Y. , Esaki T. , Tambaria T. N. 
Published: November 2023

Abstract
The current thermal recovery processes of bitumen consume tremendous amounts of water and energy and even emit greenhouse gases (GHGs). As a solution, this study proposes a cold bitumen recovery that adapts the CO2 huff-n-puff process combined with horizontal wells and gravity drainage on the premise that CO2 gas is more soluble in bitumen at lower temperatures. This process generates CO2-based foamy bitumen, introduces swelling phenomenon in the huff stage due to CO2 dissolution in the bitumen phase, and provides foam expansion in the puff stage because of CO2 liberation. Due to pressure differences, gravity, and foam expansion, foamy bitumen is drained into the production well. Therefore, the current study aims to evaluate the potential of this method after the impacts of important parameters on the foam expansion such as temperature, pressure, viscosity, and solubility are investigated. The studied conditions are 2, 3, and 4 MPa of CO2 injection pressure under temperatures of 25, 35, 45, and 55 °C. The results from the adapted CO2 huff-n-puff experiment show that the solubility of CO2 in bitumen increases at higher injecting pressures and lower temperatures. The highest expansion factors which are about 9 were obtained at the highest injecting pressure at 25 and 35 °C followed by the expansion from 3 MPa injecting pressure at 45 and 55 °C. The third place is shared by the injecting pressure of 3 MPa at 25 and 35 °C and injecting pressure of 4 MPa at 45 and 55 °C. The lowest expansion factor was obtained at the lowest injecting pressure at the highest temperature. These peculiar results indicate that temperature, pressure, viscosity, and solubility possess unique roles and strongly influence each other in a certain manner that can either benefit or hinder the foam expansion. It also depicts that with a harmonious and optimal combination of all these parameters, a high expansion of CO2-based foamy bitumen is achievable. Besides, the current highest expansion factor of this study proves that this cold production is theoretically capable of driving bitumen out of the pore spaces even without the assistance of gravity drainage or any form of heating.
Successful Deployment of New Innovative Polymer Fluid System for Coalbed Methane Hydraulic Fracturing in Hancheng Area, Shaanxi Province, China - A Case History
Authors: Goh S. H. , Ling K. T. , Niu L. , Then Y. L. , She N. N. , Melice D. T. , Enkababian P. , Bukovac T. , Liu C. 
Published: November 2023

Abstract
Developing coalbed methane (CBM) in China has faced a series of unprecedented technical challenges over the past decade. Apart from the geological constraints of the coal seams that have very low cleat permeabilities, the poor performance of the fracturing fluid system has also been identified as one of the contributing factors leading to subpar gas production rate after well intervention. Innovation in borate crosslinking ability is a critical need for CBM fracturing advancement.
With the objective of enhancing the functionality of guar-based fracturing fluid for this application, a self-buffered liquid hybrid borate-based crosslinker has been developed in the laboratory. Unlike conventional borate crosslinker behaviour, instant crosslinking occurred typically when polymer loading was significantly low. Controllable crosslinking was achieved by impeded dissolution of borate feature, which, in turn, allowed sufficient delay time in polymer crosslinking.
This breakthrough in the ultralow guar (ULG) fracturing fluid system was viable without compromising its viscosity stability. The polymer loading of the crosslinked fluid was further decreased to 11-lbm and the fluid still demonstrated sufficient shear recovery in laboratory rheological testing. In field application, this fluid causes less formation damage and provides better flowback efficiency in the coalbed formation.
The benefit of the ULG system has been validated by several field applications. In all, 8100 m3 of ULG crosslinked fluid has been applied in coal seam hydraulic fracturing across 22 wells, with total of 31 stages, including both horizontal and vertical wells in the Hancheng area, Ordos Basin. A field implementation case history will be discussed in this paper.
The novel crosslinker is capable of overcoming the inadequacy of conventional borate crosslinker used in guar-based fracturing fluid by addressing the performance needs for fracturing CBM wells.
Geology Quality: A Method of Using 3D Geology Model Data for Completion and Fracturing Optimization in Horizontal Wells
Authors: Liu Yuan , Lei Qihong , He Youan , Huang Tianjing , Ma Shuwei , Ma Fujian , Li Haoyan , Luo Yin 
Published: November 2023

Abstract
Engineered completion designs consider reservoir quality (RQ) and completion quality (CQ) for horizontal well completion optimization. This is more effective than the geometric strategy that is sometimes used. However, both RQ and CQ are derived from the wellbore logs, which means the true geology and reservoir properties inside the geology model (e.g., the thickness of the pay zone or the properties of the rocks) are not fully utilized. That information is often hidden inside the 3D geological model grid properties, and the current completion and fracturing practice cannot use 3D data for optimizations.
To address this challenge, we define geology quality (GQ) via 3D models, which aims to support completion and fracturing optimizations with geology considerations quantitatively. GQ is generated by projecting the total effective grid property to the wellbore, so that all the grid in 3D space that is potential for production contribution is cumulated on the nearest wellbore in the form of a 1D wellbore log. This allows GQ to be used in combination with RQ and CQ. While RQ and CQ answer the completion staging design and perforation refinement, GQ is especially useful for the design parameter variations of the hydraulic fracturing.
Recently, the GQ concept was used in a six-well campaign in an Ordos shale oil project. In this case, GQ was generated based on the grid property of the 3D geology model. The fracturing parameters, particularly the volume and rate, were designed in proportion to the GQ level along the wellbore for each well. Chemical tracer was pumped into two wells to measure the contribution along the laterals, which also aimed to verify GQ practice. The production results from the campaign outperform the offset platforms and the tracer results from two wells match GQ calculations.
GQ is an important new element to enrich the current existing geoengineering workflow. Case studies show the definition and application of GQ not just improve the consistency of the job design, execution, and evaluations, but also enhance the productivity of the well. The concept of using the 3D geology model quantitatively in the form of GQ ultimately helps to upgrade the engineered completion to the next level.
Optimizing the Wellbore Trajectory of Directional Wells Considering Wellbore Stability Subjected to the Non-Independence and Uncertainty of Geomechanical Parameters
Authors: Chen Fuzhi , Gao Jiajia , Feng Yutian , Lin Hai , Zhang Binqi , Bian Gengchen , Yang Weidong , Ouyang Hui 
Published: November 2023

Abstract
Effectively analyzing the wellbore stability risk in directional wells plays an important role in the exploration of oil and gas resources in complex deep formations. For the smooth execution of the drilling process, wellbore stability is related to the rock strength characteristics of the formation and the stress state of the rock around the borehole, which in turn is directly affected by the wellbore trajectory inclination and azimuth. The stress state depends on the magnitude of in-situ stresses. However, the uncertainty and non-independence of geomechanical parameters greatly impact the predicting wellbore instability pressure and wellbore stability evaluation. Therefore, this paper effectively combines the Monte Carlo method with the Nataf transformation to sample and simulate the geomechanical parameters and realize the quantitative risk assessment (QRA) of wellbore instability. The parameter sensitivity characteristics of borehole collapse and fracture pressures under different wellbore trajectories and stress states are studied on this basis. The main research shows that the risk assessment results of wellbore instability based on parameter uncertainty indicate that the predicted collapse equivalent density usually increases and the fracture pressure equivalent density decreases where the reliability is greater than 50%, which leads to a significantly narrower safe mud weight window. In addition, the influence of parameter uncertainty on fracture pressure is significantly greater than that on collapse pressure. The correlation coefficient is used to constrain the reservoir geomechanical parameters, which maintains the linear characteristics between the parameters, and then significantly reduces the uncertainty range of wellbore instability pressure. The uncertainty of in-situ stress parameters makes it possible for the formation rock to experience the type of stress state that changes from conventional strike-slip faults to normal faults. However, this possibility of stress state transition obviously affects the selection of wellbore trajectory optimization. The rock mechanics parameters including elastic modulus, Poisson’s ratio, cohesion, internal friction angle, and tensile strength have a weak effect on the collapse pressure and fracture pressure of arbitrarily inclined boreholes. However, the obvious sensitivity of in-situ stresses depends on the change of wellbore trajectory in deviated/horizontal wells. As for the vertical well, the maximum and minimum horizontal in-situ stresses always are the primary sensitivity factors of borehole collapse and fracture pressures, respectively. The methodology shown in this paper provides important guidance for engineering design by calculating the probability of wellbore trajectory optimization.
Daya Tampung Beban Pencemaran Nitrat dan Fosfat Sungai Brantas Ruas Sengkaling-Tlogomas, Kota Malang
Authors: Wiratmojo M. Adi , Tri Budi Prayogo  , Emma Yuliani  
Published: November 2023

Abstrak: Sungai Brantas mengalir dan melintasi Kota Malang berpotensi mengalami degradasi kualitas air imbas dari transfigurasi tata guna lahan dan eskalasi penduduk di daerah Sub-Urban sepanjang sungai Ruas Sengkaling-Tlogomas, Kota Malang. Penelitian dilakukan pada bulan Februari-Maret-April tahun 2022 dengan sungai sepanjang ± 4,0 km. Penelitian ini bertujuan untuk mengidentifikasi kondisi eksisting kualitas air Sungai Brantas untuk mengitung beban pencemar, serta daya tampung beban pencemar pada Sungai Brantas dengan Qual2Kw. Parameter pencemar yang diteliti adalah Nitrat dan Fosfat. Kegiatan dan masalah di sekitar Sungai Brantas yang menjadi potensi pencemaran sungai pada bagian hulu adalah pertanian, serta menuju bagian hilir adalah domestik warga. Hasil dari penelitian ini kadar nitrat berkisar antara 3,24-3,56 mg/l (tidak melampaui baku mutu kelas II). Demikian, sementara itu kadar fosfat berkisar antara 10,2-11.94 mg/l (melampaui baku mutu kelas II). Daya Tampung Beban Pencemar Nitrat 7,481 kg/hari dan Fosfat 1,359 kg/hari. Disimpulkan bahwa sungai masih mampu menampung beban pencemar harian Nitrat dan Fosfat.

Abstract: The Brantas River flows and crosses Malang City which has the potential to experience water quality degradation as a result of land use transfiguration and population escalation in Sub-Urban areas along the Sengkaling-Tlogomas River Section, Malang City. The research was conducted in February-March-April 2022 with a ± 4.0 km long river. This study aims to identify the existing condition of the water quality of the Brantas River to calculate the pollutant load, as well as the carrying capacity of the pollutant load on the Brantas River with Qual2Kw. The pollutant parameters studied were Nitrate and Phosphate. Activities and problems around the Brantas River that are potential for river pollution in the upstream part are agriculture, and towards the downstream are domestic residents. The results of this study ranged from 3.24-3.56 mg/l of nitrate (not exceed quality standards class II). While the phosphate levels ranged from 10.2-11.94 mg/l (over quality standards class II). The carrying capacity of the Nitrate Contaminant Load is 7.481 kg/day and Phosphate is 1.359 kg/day. It was concluded that the river is still able to accommodate the daily pollutant load of Nitrate and Phosphate
Applications of Clinical Decision Support Systems in Diabetes Care: Scoping Review
Authors: Huang Shan , Liang Yuzhen , Li Jiarui , Li Xuejun 
Published: November 2023

Background
Providing comprehensive and individualized diabetes care remains a significant challenge in the face of the increasing complexity of diabetes management and a lack of specialized endocrinologists to support diabetes care. Clinical decision support systems (CDSSs) are progressively being used to improve diabetes care, while many health care providers lack awareness and knowledge about CDSSs in diabetes care. A comprehensive analysis of the applications of CDSSs in diabetes care is still lacking.

Objective
This review aimed to summarize the research landscape, clinical applications, and impact on both patients and physicians of CDSSs in diabetes care.

Methods
We conducted a scoping review following the Arksey and O’Malley framework. A search was conducted in 7 electronic databases to identify the clinical applications of CDSSs in diabetes care up to June 30, 2022. Additional searches were conducted for conference abstracts from the period of 2021-2022. Two researchers independently performed the screening and data charting processes.

Results
Of 11,569 retrieved studies, 85 (0.7%) were included for analysis. Research interest is growing in this field, with 45 (53%) of the 85 studies published in the past 5 years. Among the 58 (68%) out of 85 studies disclosing the underlying decision-making mechanism, most CDSSs (44/58, 76%) were knowledge based, while the number of non-knowledge-based systems has been increasing in recent years. Among the 81 (95%) out of 85 studies disclosing application scenarios, the majority of CDSSs were used for treatment recommendation (63/81, 78%). Among the 39 (46%) out of 85 studies disclosing physician user types, primary care physicians (20/39, 51%) were the most common, followed by endocrinologists (15/39, 39%) and nonendocrinology specialists (8/39, 21%). CDSSs significantly improved patients’ blood glucose, blood pressure, and lipid profiles in 71% (45/63), 67% (12/18), and 38% (8/21) of the studies, respectively, with no increase in the risk of hypoglycemia.

Conclusions
CDSSs are both effective and safe in improving diabetes care, implying that they could be a potentially reliable assistant in diabetes care, especially for physicians with limited experience and patients with limited access to medical resources.

International Registered Report Identifier (IRRID)
RR2-10.37766/inplasy2022.9.0061