bluuebunny/crossref_metadata_2025 huggingface dataset:
Spiral Arm Formation of Galaxies Through ROTASE Mechanism Is Perfectly Demonstrated by Falling Rockets Venting Fuel
Authors: Pan Hongjun
Published: June 2023

This paper illustrates that the ROTASE model proposed by the author for the formation of spiral arms of galaxies is nicely demonstrated by the spirals generated by rockets venting fuel during free fall. The patterns of spirals by the falling rockets strongly support that the spiral galaxies with perfect central symmetry have to be originated from the galactic centers, and the spiral arms and the galactic bars are bound together as “rigid” body. The exclusive presence of a rear side trail effect in galaxies indicates the absence of co-rotation, and the rotation of spiral arms is faster than the galactic matters. The exact nature of X-matter remains an open question.
Serum C-Reactive Protein to Albumin Ratio as a Reliable Marker of Diabetic Neuropathy in Type 2 Diabetes Mellitus
Authors: Aktas Gulali
Published: June 2023

Type 2 diabetes mellitus may be complicated with chronic complications including diabetic neuropathy (DN). Timely diagnosis is crucial in treatment and maybe reversal of this complication. C reactive protein to albumin ratio (CAR) is considered as a marker of inflammation in various diseases that characterized with acute or chronic inflammation. Since diabetic neuropathy and type 2 diabetes mellitus are also associated with chronic, low grade inflammation, we aimed to study CAR levels of type 2 diabetic subjects with diabetic neuropathy and to compare to those in patients without diabetic neuropathy. Type 2 diabetic patients presented to our institutional outpatient clinics were divided into two according to the presence of DN. Subjects with DN were listed as DN group and others were as non-DN group. Characteristics and laboratory data, including CAR, in DN and non-DN groups were compared. Median CAR of the DN and non-DN groups were 2,19 (0,2-49)% and 0,56 (0,02-5,8)%, respectively (p<0.001). CAR was significantly and positively correlated with age (r=0.15, p<0.001), weight (r=0.19, p=0.01), BMI (r=0.11, p=0.03), waist circumference (r=0.10, p=0.046), fasting plasma glucose (r=0.14, p=0.004), serum creatinine (r=0.25, p<0.001), triglyceride (r=0.17, p<0.001), and LDL-cholesterol (r=0.13, p=0.001) levels. Moreover, CAR was inversely correlated with eGFR levels (r=-0.16, p<0.001). The sensitivity and specificity of CAR (when higher than 1,02%) in predicting diabetic neuropathy were 78% and 73%, respectively (AUC: 0.84, p<0.001, 95% CI: 0,82-0,87). Moreover, high CAR level was an independent risk factor of diabetic neuropathy (p<0.001, OR: 1.34, 95% CI: 0.48-1.62). In conclusion, elevated CAR levels could be considered as a marker of diabetic neuropathy.
Test Structures for the Characterization of the Gate Resistance in 16nm FinFET RF Transistors
Authors: Lauritano Mario , Baumgartner Peter
Published: June 2023

The gate resistance is a parasitic element in transistors for RF and millimeter-wave circuits that can negatively impact power gain and noise figure. To develop accurate device models, a reliable measurement methodology is crucial. This article reviews the standard measurement methodology used in the literature and proposes also an additional method, which is evaluated using suitable test structures in a 16nm FinFET process. The advantages and disadvantages of the two approaches are discussed along with their respective application scenarios
Percutaneous superimposed O-arm -MRI Navigated Biopsy for Spinal Column Pathologies
Authors: Al-Smadi Mohammad Walid , Kozma István , Aslan Siran , Bölöni Balázs , Viola Árpád
Published: June 2023

Classifying spinal tumors can be challenging due to nonspecific clinical and radiological qualities, and a precise biopsy is crucial for an accurate diagnosis and treatment planning. This study aimed to enhance the accuracy and efficiency of spinal biopsies integrating Cone Beam Computed Tomography (CBCT) and magnetic resonance imaging (MRI) modalities using an O-arm CT navigation system. Eighteen patients with diverse spinal lesions underwent 18 biopsies following the Stealth Station navigation system Spine 8 protocol. Preoperative MRI scans were merged with intraoperative CT navigation systems for continuous monitoring during the biopsy process. The combined imaging technique accurately identified the diseased lesion type in all biopsies, demonstrating 100% sensitivity and specificity. In conclusion, combining MRI and CT imaging modalities significantly improved spinal biopsy accuracy and efficiency, differentiating between pathological entities. However, large-scale studies are desired to validate these findings and investigate potential benefits in different clinical scenarios. Although this method requires general anesthesia, its potential profits in avoiding misdiagnosed lesions and decreasing the need for further invasive procedures make it a promising approach for improving spinal biopsy accuracy and efficiency.
CoolBat3D – Development of an Innovative Temperature Man-Agement System With an Implemented Cooling Circuit, Consid-Ering Additive Manufacturing Options for Safe Operation of Li-Ion Battery Packs
Authors: Thaler Stephan M. , Zwatz Josef , Zettel Dominic , Hauser Robert , Lackner Roman
Published: June 2023

The broad acceptance of electromobility depends heavily on the performance and service life of the battery technology used. Lithium-ion battery technology is currently the most promising energy storage technology for mobile applications, but the performance and capacity of the cells is extremely temperature sensitive. Especially in these new complex and powerful applications there is a significant need for thermal management. Depending on the ambient conditions, part of the effective battery energy must therefore be used to temper the system. So far, mainly active components have been used for this task. This not only reduces the overall efficiency, but also increases the weight, volume and maintenance requirements of the system. In the present work, an alternative battery temperature management system (BTMS) was developed. A concept based on latent heat storage materials was created, which uses the advantages of thermal energy storage and the design freedom of additive manufacturing technology, and its suitability for use in battery applications was checked. On the one hand, the use of systems for storing thermal energy was researched and, on the other hand, an innovative cooling concept was created considering new production possibilities.
A Novel Framework for Production Planning and Class-Based Storage Location Assignment: Multi-Criteria Classification Approach
Authors: YERLİKAYA MEHMET AKİF , ARIKAN FEYZAN
Published: June 2023

For effective warehouse management, various criteria should be taken into consideration in terms of inventory management, demand, transportation distance, usage area, delivery-waiting times, and minimizing the costs that may arise from them. Because, the purpose of the product assignment problem is to minimize the total transport distance during storage and to reduce the space required for product assignment. However, the storage location assignment problem (SLAP) occurs simultaneously with production planning activities in real life. In this study, an integrated mixed-integer nonlinear (MINLP) mathematical model is proposed, which includes the assignment of products to storage areas and production planning, using the TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) class based policy for storage systems where multiple criteria are important. In the TOPSIS class-based policy, weight and waiting time criteria are taken into account, as well as the COI (Cube-per-order index index), which is widely used in the literature. In addition, a decision support system flow has been proposed that takes into account the single criterion, multiple criteria and COI index criteria of the developed model and provides its integration with different product assignment policies. Detailed literature research; It has been revealed that the proposed mathematical model and decision support system flow have the feature of applying an existing field of science to a new problem.
Pengabdian Kepada Masyarakat Penerapan Teori Kaizen untuk Meningkatan Kualitas Usaha Keripik Talas di UKM Asyifa Oleh-Oleh
Authors: Budaraga I Ketut , Devi Wellas Sri
Published: June 2023

Talas merupakan bahan pangan lokal di Sumatera Barat mempunyai peranan penting untuk menjaga ketahanan pangan. Talas banyak dimanfaatkan sebagai makanan olahan di daerah-daerah. Permasalahan dijumpai pada UKM  Asyifa oleh-oleh perlu adanya peningkatan kualitas dan penerapan manajemen yang baik. Tujuan pengabdian ini untuk memberikan tambahan informasi penerapan teori KAIZEN untuk peningkatan kualitas produksi kepada UKM  Asyifa Oleh-Oleh. Metode yang digunakan dalam pengabdian adalah kunjungan lapangan disertai dengan ceramah secara timbal balik dilakukan secara langsung dan daring. Dalam diskusi tidak bersifat menggurui agar pesan inovasi yang ingin disampaikan sampai kepada UKM. Materi diskusi yang disampaikan masalah penerapan teori KAIZEN yaitu UKM perlu adanya perencanaan produksi, proses produksi pengolahan talas yang baik, adanya control terhadap mutu produksi serta kegiatan aktivitas selanjutnya, artinya ada usaha  peningkatan mutu secara terus menerus (continuous improvement).   Hasil yang diperoleh UKM menyambut baik masukan tersebut, dan kedepan akan dilaksanakan secara bertahap, disesuaikan dengan kemampuan SDM yang dimiliki oleh UKM Asyifa Oleh-Oleh.  Saat ini prospek pemasaran kripik talas cukup bagus, pemasaran sudah dilaksanakan di wilayah Sumatera Barat dan luar Sumatera Barat. Keripik UKM Asyifa oleh-oleh belum dikemas dengan baik. Adanya UKM ini sangat membantu peningkatan pendapatan masyarakat disekitarnya.      

 

Kata kunci: Produksi, Keripik Talas, Kaizen, Kualitas
Perancangan Checklist dan Workflow untuk Percepatan Proses Pemenuhan Persyaratan Sertifikasi SNI dan Penilaian Manfaat Ekonomi pada IKM Batik di Surakarta
Authors: Sutopo Wahyudi , Fahma Fakhrina , Zakaria Roni , Hisyam Muhammad , Suletra I Wayan , Priyandari Yusuf , Munifah Munifah , Yuniaristanto Yuniaristanto
Published: June 2023

Pandemi Covid-19 telah memukul berbagai sektor usaha di dalam negeri, baik usaha berskala besar maupun usaha mikro kecil dan menengah (UMKM). Berbagai upaya perlu dilakukan untuk untuk menjaga eksistensi UMKM. Salah satu industri yang perlu mendapat perhatian adalah industri batik, karena batik merupakan karya bangsa Indonesia yang banyak dikagumi. Transformasi penjualan melalui mengakibatkan persaingan usaha menjadi sangat ketat dan pemenuhan kualitas produk merupakan salah satu kunci untuk memenangkan persaingan tersebut. Produk yang berkualitas adalah produk yang mampu membuktikan bahwa produknya sudah memenuhi standar ditetapkan. Oleh sebab itu penting bagi IKM untuk melakukan standarisasi dan sertifikasi produk jika ingin memasuki pasar global.  Untuk itu pada kegiatan pengabdian ini dilakukan pembuatan teknologi tepat guna berupa perancangan proses pemenuhan persyaratan sertifikasi SNI tentang produk batik (dalam bentuk checklist dan workflow) pada IKM mitra untuk lima kriteria persyaratan sertifikasi, yaitu personal, company, managerial, technical dan economy.  Selain itu juga dilakukan asesmen manfaat ekonomi penerapan standar dengan pendekatan ISO Methodology – Economic Benefit Standard.  Tahapan dalam ISO Metodologi meliputi analisis value chain, analisis value driver, identifikasi dampak standar, dan penilaianl. Dari kegiatan ini dihasilkan panduan atau pedoman proses sertifikasi SNI yang sederhana dan aplikatif dengan penyederhanaan persyaratan yang dapat menjadi referensi bagi IKM batik secara umum di Indonesia.  Hasil penilaian Hasil manfaat ekonomi penerapan standar pada IKM Batik Rp 60.750.000,00.

 

Kata kunci: Sertifikasi; IKM, SNI Batik; Workflow; Dampak Ekonomi Standar.
Penerapan Teknologi Pencacah Multi Blade Pada Proses Pengolahan Limbah Ikan sebagai Upaya Pemberdayaan Nelayan Di Desa Berahan Kulon, Kecamatan Wedung Kabupaten Demak
Authors: Fitriana Laila , Saputro Herman , Bugis Husin , Siswanto Budi , Ranto Ranto , Muslim Riyadi
Published: June 2023

Desa Berahan Kulon Kec. Wedung Kab. Demak merupakan desa daerah pesisir pantai utara Jawa yang memiliki potensi perikanan yang cukup besar. Kegiatan usaha itu meliputi usaha perikanan air laut, air payau dan air tawar. Hasil tangkapan ikan laut setiap tahunnya tidak kurang dari 600 ton, serta budidaya ikan air tawar mencapai 97.6 ton per tahun. Potensi produksi ikan tersebut menyisakan limbah ikan dan kerang yang belum termanfaatkan dengan baik. Kegiatan yang dikeloala kelompok petani tambak dan nelayan tersebut juga memiliki masalah pada suplai dan harga pakan ikan yang selalu berubah-ubah. Akibat permasalahan tersebut usaha tambak yang dikelola melalui Kelompok Budidaya Ikan Margo mulyo mengalami kerugian. Adanya potensi dan permasalahan tersebut maka dilakukan kegiatan pengabdian masyarakat terkait kemandirian pakan ikan dengan penerapan teknologi mesin pembuat tepung ikan. Penerapan teknologi pencacah multi blade untuk memudahkan proses pengolahan limbah ikan tangkapan nelayan menjadi tepung ikan. Kegiatan kemitraan ini difokuskan bagaimana menyediakan alat produksi tepung ikan dan pelatihan produksi bagi nelayan. Kegiatan kemitraan UMKM Margo Mulyo Abadi dengan UNS ini mampu menjadi solusi akan isu yang berkembang, sekaligus mampu meningkatkan nilai ekonomis limbah ikan sehingga terdapat peningkatan pendapatan bagi para anggotanya.

 

Kata kunci: Pemberdayaan; Teknologi Pencacah; multi-blade; limbah ikan; tepung ikan.
Pelatihan Pemanfaatan Microsoft Teams sebagai Alternatif Media Pembelajaran Daring di Universitas Sebelas Maret Surakarta
Authors: Sakroni Sakroni , Ngadimin Ngadimin , Wahyuningsih Daru
Published: June 2023

Microsoft Office lebih dikenal sebagai aplikasi desktop perkantoran. Seiring dengan perkembangan teknologi, Microsoft Office bertranformasi menjadi aplikasi yang dapat dimanfaatkan secara luas, dapat dipakai dimana saja, kapan saja, dengan media apa saja secara online. Banyak fitur-fitur baru yang dapat dimanfaatkan oleh semua kalangan termasuk dunia Pendidikan. Salah satu aplikasi yang dapat digunakan dalam dunia Pendidikan adalah Microsoft Teams. Microsoft teams dapat menjadi salah satu platform pembelajaran yang memungkinkan pendidik dan peserta didik berkolaborasi maupun berinteraksi pada saat pembelajaran daring. UNS telah melakukan kerjasama dengan Microsoft Indonesia dan sudah  melakukan deploy pemanfaatan office 365. Kurangnya sosialisasi dan dukungan teknis menyebabkan pemanfaatannya belum maksimal. Untuk dapat memanfaatkan aplikasi Microsoft Teams sebagai media pembelajaran daring diperlukan pelatihan. Tujuan pelatihan adalah untuk meningkatakan kompetensi dan literasi digital pemangku pembelajaran. Pelatihan diadakan secara luring selama 3 hari berturut-turut. Sasaran peserta pelatihan adalah 30 orang dosen pengampu matakuliah. Peserta pelatihan memberikan respon yang positif terhadap kegiatan ini. Hal ini dapat dilihat dari keaktifan peserta selama pelatihan berlangsung. Mereka merasa pelatihan ini sangat berguna bagi peningkatan kompetensi dan literasi pemanfaatan teknologi digital sebagai alternatif aplikasi pembelajaran daring.

Kata kunci: Microsoft Teams; Office 365; LMS.
Extração sequencial BCR para frações geoquímicas e avaliação de Zn, Ni, Cd, Cu e Pb nos sedimentos costeiros no Complexo Portuário de Santos, Sudeste do Brasil
Authors: F. Delgado Jéssica de , S. Lima Leonardo da , Vieira Khauê , Baptista Neto José Antônio , Fonseca Estefan Monteiro da
Published: June 2023

As variações da coluna d'água no ambiente aquático, motivadas por processos naturais ou antropogênicos, podem afetar a estabilidade de metais-traço no sedimento do Complexo Portuário de Santos (CPS), localizado no sudeste do Brasil. Metais-traço, como Cu, Zn, Ni, Pb e Cd, podem afetar negativamente os compartimentos ecológicos e biológicos da água estuarina. Para avaliar a condição do sedimento do CPS, este artigo investigou a fração geoquímica de metais-traço sedimentares aplicando a abordagem de extração sequencial BCR (European Community Bureau of Reference - Gabinete de Referência da Comunidade Europeia). A matéria orgânica e o tamanho de grão fino, característicos de um ambiente estuarino, mostraram uma influência direta na dinâmica de concentração de metais-traço em sedimentos, especialmente para Pb, Cd e Ni. No caso específico de Zn e Cu, havia uma possível fonte de contaminação no porto. A maior fração dos metais estudados era não residual, potencialmente mobilizável em um ambiente em que a variação dos parâmetros físico-químicos da coluna d'água é altamente variável, algo frequente em ambientes estuarinos.
Palavras-chave: especiação de metais-traço; Porto de Santos; sedimento; impacto ambiental.
Determining Economic Growth and Life Expectancy Linkages in Indonesia: A Simultanous Equation Model
Authors: Setiawan Avi Budi , Yusuf Mochammad , Yudistira Danu , Nugroho Agus Dwi
Published: June 2023

Life expectancy become the main indicators of the health parameters in the population and development process. However, there is a relationship between life expectancy and growth which is represented by the inconsistency of previous studies. This study aims to reveal a linkage between life expectancy and economic growth, and analyzing factors that influence both of them. Two-Stage Least Square (2SLS) was used for simultaneous modelling equations to fill the existing literature gaps. Based on the 2SLS estimation relationship, it was found that there is a simultaneous relationship of life expectancy economic growth. Furthermore, it was found economic growth was significantly influenced by the decreasing dependency ratio, unemployment rate, and poverty. Furthermore, life expectancy is positively influenced by health spending and significantly decreases by the increased poverty rate. Therefore, mortality and carbon emissions had insignificant adverse effect. However, poverty and carbon emissions had a negative had insignificant adverse effect. This result suggests the government formulate policies to prioritize larger budget allocations in the education sector as a safety net program, cash transfers, and labor pensions.
IMPLEMENTATION OF CORPORATE BRAND IDENTITY MATRIX IN BUILDING CORPORATE BRAND IDENTITY
Authors: Krissanya Nofriska , Widyaningsih Yulia Arisnani
Published: June 2023

Tujuan dari penelitian ini adalah mengimplementasikan kerangka Corporate Brand Identity Matrix (CBIM) untuk mengembangkan identitas mereka perusahaan New Company (New Co) dan mengetahui pemahaman karyawan XYZ atas identitas merek perusahaannya. Teknik wawancara mendalam (in depth interview/ IDI) digunakan untuk memperoleh data primer dengan metode studi kasus tunggal. Responden dalam penelitian ini adalah perwakilan karyawan dan manajemen eksekutif XYZ dari berbagai posisi dan unit kerja. Untuk mereprsentasikan karyawan dan manajemen XYZ, sebelas orang responden dari berbagai posisi dan unit kerja dilibatkan dalam penelitian ini. Analisis data hasil wawancara dilakukan melalui teknik analisis konten, analisis tematik dan analisis triangulasi sumber untuk merumuskan hasil penelitian ini. Berdasarkan hasil penelitian, pemahaman identitas merek perusahaan XYZ lebih terkonsentrasi pada area pemasaran atau eksternal, khususnya identitas visual. Selanjutnya diperoleh kerangka CBIM untuk New Co, dimana terdapat beberapa elemen yang mirip dengan kerangka CBIM XYZ.
Team Approach: The Unstable Trauma Patient
Authors: Baker Hayden , Erdman Mary-Kate , Christiano Anthony , Strelzow Jason A.
Published: June 2023

» A multidisciplinary, integrated, and synergistic team approach to the unstable polytrauma patient is critical to optimize outcomes, minimize morbidity, and reduce mortality.

» The use of Advanced Trauma Life Support protocols helps standardize the assessment and avoid missing critical injuries

» Effective and open dialog with consulting specialists is paramount for effective team-based care.

» Orthopaedic surgeons should play an important role in the rapid assessment of potentially life-threatening and/or limb-threatening injuries including pelvic ring disruption, open fractures with substantial blood loss, and dysvascular limbs.
Distal Femur Anterior Hemiepiphysiodesis for Fixed Knee Flexion Deformity in Neuromuscular Patients
Authors: Al Badi Hamid , Lorange Justin-Pierre , Alzeedi Muadh , Marwan Yousef , Bernstein Mitchell , Hamdy Reggie C.
Published: June 2023

Background:

In the past decade, distal femur anterior hemiepiphysiodesis for fixed knee flexion deformity has gained popularity. In this study, we aim to systematically review the literature on this technique as a treatment for fixed knee flexion deformity in patients with neuromuscular disorders.

Methods:

A systematic review was performed in the following databases: PubMed, Embase, and Medline. The inclusion criteria included anterior hemiepiphysiodesis of the distal femur for patients with neuromuscular disorders and fixed knee flexion deformities.

Results:

Our search yielded 419 titles. A total of 12 articles were qualified for final review based on the inclusion and exclusion criteria. The total number of patients was 279, with 483 knees corrected. The male to female ratio was 2.1:1, and the mean age of the patients was 11.3 ± 1.4 years (range 4-17 years). The mean preoperative flexion deformity was 23.1° ± 10.0° (range 10°-90°). The mean residual flexion deformity at the final follow-up was 8.6° ± 9.0° (range 0°-32.5°), which corresponds to a statistically significant decrease compared with the preoperative deformity (p < 0.05).

Conclusion:

Anterior hemiepiphysiodesis for fixed knee flexion deformity provides favourable outcomes with low complication rates in patients with neuromuscular disorders. Future studies should focus on comparing the long-term outcomes of the different metal implants used for these operations.

Level of Evidence:

Level III. See Instructions for Authors for a complete description of levels of evidence.
Using eCalc™ for Designing a Low Emission Reservoir Drainage Strategy for Oseberg C
Authors: Mæland Ingvild , Alaeddine Leen , Ånes Hallstein Magne , Chen Shi , Lødøen Ole Petter , Martinsen Frode
Published: June 2023

Oseberg is a large offshore field in North Sea with 4 main installations and several subsea developments. Production started in 1988. The field is covering the BRENT group. The study focuses on the Oseberg C platform which produces from the northern area of the Oseberg Main field. The Oseberg C involves a low-pressure production project executed in the fall of 2022. The timing of when to eventually reduce the topside separation pressure even more, and/or stop or reduce stop gas injection and instead export the produced gas via an existing multiphase pipeline to the Field center will be investigated in this study.

The main objective is to illustrate a workflow that allows revising the drainage strategy while simultaneously reducing scope 1 CO2 emissions to attain a low emissions reservoir management strategy along with minimizing the losses in reserves. Mitigating reserves losses will be studied through different sensitivities.

Several factors must be considered when studying modifications in the drainage strategy. Well delivery potential, gas export pressure to the Field center and the gas capacity at Field center are all important boundary conditions. A reservoir simulation model is used to study the reservoir impact of lowered OSC inlet pressure and effect of stopping the gas injection at different dates. A set of scenarios capturing consistently reservoir simulation and topside models are designed to assess the optimal timing of when to stop gas injection on Oseberg C. The optimal timing is evaluated by considering reservoir recovery and CO2 emissions.

Reserves evaluation is performed using a reservoir simulation model (ECLIPSE), and emission forecasts are performed using eCalc™ (Skjerve et al., 2022). eCalc™ is the name of a software tool for high-quality emission forecasting. eCalc™ allows the integration of subsurface and operational knowledge and calculates emission forecasts directly relating drainage strategy to operational strategies and process equipment. The emission sources change significantly with the drainage strategy assumptions leaving correlation models less suited. eCalc™ is using mechanistic models of the topside processes and therefore can predict the effects of large changes in the drainage strategy and topside process.
ESG, Sustainability and Decarbonization: An Analysis of Strategies and Solutions for the Energy Industry
Authors: Agbaji Armstrong Lee , Morrison Reid , Lakshmanan Sammy
Published: June 2023

Various studies have shown that fossil fuels are the main driver for climate change and mitigating CO₂ emissions has been a major issue for the oil and gas industry. Directly and indirectly, the industry accounts for 42 percent of global emissions and it is now being referred to as ground zero for climate change. Pressure continues to mount from both the investor community and various governments who are demanding climate action and are proposing new requirements for businesses to publish specific details of how they will adapt and achieve net-zero by 2050. Leaders across the energy industry are now addressing these issues by incorporating ESG into their business. ESG issues cut across industries and lines of service, and these issues are ever evolving. Each industry has vastly different sources of emissions, therefore their means of decarbonization differ greatly. Understanding the emissions associated with oil and gas operations is crucial to evaluating and tracking the sustainability factors impacting the industry.

This paper takes a deep dive into what sustainability and ESG looks like in oil and gas operations and addresses the key drivers of ESG in the oil industry. It details the ESG issues that are material to all sectors of the industry and provides valuable insights on how organizations can embed sustainable business practices into engineering design and business operations. It also addresses the specific challenges ESG poses to the industry, suggests a multi-pronged approach to tackle decarbonization, and looks at various opportunities that the wave of ESG activities present for the industry.

Succeeding in business is no longer just about profitability, but about how companies perform on a variety of ESG-related issues. It is now a business imperative to undergo a sustainability transformation, and oil industry operations should be designed with sustainability in mind. Sustainability and ESG should be part of the industry’s DNA and should be integrated in all its activities. ESG issues represent the language of the future and addressing it will become as significant for the oil industry as digital transformation; not only because of its broad geographical footprint, but also its operations and assets, many of which are GHG emitters.

ESG is not just a compliance exercise, it's a strategic decision. To meet the goals of the Paris Agreement, the oil industry should strive to become a net-zero GHG emitter. Without a net-zero story, it may realize that there might not be much interest in hearing the rest of its story. The net-zero equation is not yet solved, but it can be, with bold action and smart innovation. No other industry is better positioned to solve this than the oil and gas industry.
Business Model of Carbon Capture and Storage (CCS) Projects for High-CO2 Fields
Authors: Lot Hasnor , Yeow Andrew , Buang@Mahmood Anuar , Ismail Badrul Hisyam , Zainal Abidin Muhamad Adib , Wan Abdul Wahab Wan Adli
Published: June 2023

High-CO2 gas fields present a dilemma to Host Government wanting to both ensure security of supply and achieve net zero aspiration. While carbon capture and storage (CCS) technology holds promise of technical feasibility to unlock these fields, its commercial success ultimately hinges on the choice of an appropriate business model. This study compares the economics of the traditional business model i.e., CCS as part of the upstream petroleum operation dedicated to a Production Sharing Contract (PSC) vs. the alternative business model i.e., a regional CCS hub separately managed by a Special-Purpose Vehicle (SPV).

To maximize the return on its investment in a gas value chain, Host Government aims to minimize the upstream cost of gas (COG), which in turn comprises the technical cost, fiscal/tax charge, and cost of capital components. Thus, in this paper, the business models are compared in terms of their COG, and the reasons for the differences are further analyzed by looking at the drivers affecting the components. To illustrate the comparison numerically, synthetic technical data based on several recent CCS projects are evaluated under Malaysian petroleum fiscal arrangement and tax regime. The scope of the CCS projects contemplated in this study is restricted to managing the CO2 inherent in upstream high-CO2 gas fields.

The paper finds that the alternative business model outdoes the traditional in several ways. The economies of scale of a hub design optimize capital expenditure, while utilization by multiple users reduces hub operator’s risk, potentially lowering tariff. The SPV can better realize tax incentives and also benefit from a lower tax rate. In PSCs where cost recovery provisions prioritize operating expenditure over capital expenditure, upstream Contractors may prefer paying tariff per usage rather than building their own CCS facility up front. Access to cheaper financing from environmental, social, and governance (ESG) investors and government agencies, coupled with the perception of lower business risks, should also translate into a lower cost of capital. There are various spin-offs and qualitative benefits too. While the paper affirms the intuitive expectation that the alternative business model generally surpasses the traditional, it also cautions that the optimal choice may switch beyond certain thresholds (number of fields, distance between PSCs, volume of CO2, etc.). In addition to the between-model selection problem, the paper also discusses within-model fine tunings and optimization.

This paper lays out important caveats and considerations that might be of interest to petroleum authority and government policymakers tasked with the development of business model for upstream CCS projects.
Improved Hydraulic Fracture Characterization Using Representation Learning
Authors: Chakravarty Aditya , Misra Siddharth
Published: June 2023

Representation learning is a technique for transforming high-dimensional data into lower-dimensional representations that capture meaningful patterns or structures in the data. Uniform manifold approximation and projection (UMAP) enables representation learning that uses a combination of nearest neighbor search and stochastic gradient descent in the low-dimensional graph-based representation to preserve local structure and global distances present in high-dimensional data.

We introduce a new technique in representation learning, where high-dimensional data is transformed into a lower-dimensional, graph-based representation using UMAP. Our method, which combines nearest neighbor search and stochastic gradient descent, effectively captures meaningful patterns and structures in the data, preserving local and global distances. In this paper, we demonstrate our expertise by utilizing unsupervised representation learning on accelerometer and hydrophone signals recorded during a fracture propagation experiment at the Sanford Underground Research Facility in South Dakota.

Our UMAP-based representation executes a five-step process, including distance formulation, connection probability calculation, and low-dimensional projection using force-directed optimization. Our analysis shows that the short-time Fourier Transform of signals recorded by a single channel of the 3D accelerometer is the best feature extraction technique for representation learning. For the first time, we have successfully identified the distinct fracture planes corresponding to each micro-earthquake location using accelerometer and hydrophone data from an intermediate-scale hydraulic stimulation experiment. Our results from the EGS Collab project show the accuracy of this method in identifying fracture planes and hypocenter locations using signals from both accelerometers and hydrophones. Our findings demonstrate the superiority of UMAP as a powerful tool for understanding the underlying structure of seismic signals in hydraulic fracturing.
Bi-Objective Optimization of Subsurface CO2 Storage with Nonlinear Constraints Using Sequential Quadratic Programming with Stochastic Gradients
Authors: Nguyen Quang Minh , Onur Mustafa , Alpak Faruk Omer
Published: June 2023

This study focuses on carbon capture, utilization, and sequestration (CCUS) via the means of nonlinearly constrained production optimization workflow for a CO2-EOR process, in which both the net present value (NPV) and the net present carbon tax credits (NPCTC) are bi-objectively maximized, with the emphasis on the consideration of injection bottomhole pressure (IBHP) constraints on the injectors, in addition to field liquid production rate (FLPR) and field water production rate (FLWR), to ensure the integrity of the formation and to prevent any potential damage during life-cycle injection/production process. The main optimization framework used in this work is a lexicographic method based on line-search sequential quadratic programming (LS-SQP) coupled with stochastic simplex approximate gradients (StoSAG). We demonstrate the performance of the optimization algorithm and results in a field-scale realistic problem, simulated using a commercial compositional reservoir simulator. Results show that the workflow is capable of solving the single-objective and bi-objective optimization problems computationally efficiently and effectively, especially in handling and honoring nonlinear state constraints imposed onto the problem. Various numerical settings have been experimented with to estimate the Pareto front for the bi-objective optimization problem, showing the trade-off between the two objectives NPV and NPCTC. We also perform a single-objective optimization on the total life-cycle cash flow, which is the aggregated quantity of NPV and NPCTC, and quantify the results to further emphasize the necessity of performing bi-objective production optimization, especially when utilized in conjunction with commercial flow simulators that lack the capability of computing adjoint-based gradients.
Multi-Fold Increase in Production Through Polymer Flooding Application in Viscous Oil Active Aquifer Driven Reservoir of Mehsana Asset, India
Authors: Jain Nitesh Kumar , Chauhan Parth , Dadlani Hitisha Vinodbhai , Bathla Priyanka , Jain Palash , Tiwlekar Sanket Naresh , Ao C Moatoshi , Parmar Himmatbhai Shambhubhai , Raturi Vinay Chand , Dayal Har Sharad
Published: June 2023

K Sand of Field N is highly permeable and has variation in viscosity ranging from 5cP to 120cP. K sand has been producing since 1969 and has recovered about 34%. It produces with strong edge water drive mechanism. The primary recovery is about 20-22% where viscosity is 50 to 120cP, produces oil with 90% Water cut. The early rise in water cut was because of water fingers due to adverse mobility ratio. The poor areal sweep has affected the primary recovery which necessitated the application of suitable EOR. The Polymer EOR scheme was conceptualised to address adverse mobility ratio and enhance the sweep efficiency to maximize oil production. The project area was selected for polymer flood considering the moderate primary recovery due to poor areal sweep, structurally up dip area to avoid polymer dilution through aquifer, sand continuity and good reservoir facies. In the first phase, 8 inverted five spot polymer patterns were commissioned. Injection rate is 50 m3/d/well and polymer viscosity is 27cP considering the mobility ratio and high dilution effects.

The paper explains the efficient planning, monitoring activities, innovative approach to execute the scheme and mid-course correction to improve the performance of the project. The optimised project has resulted in multi-fold increase in production in challenging reservoir conditions.

The project is being monitored using pattern balancing based on the production performance monitoring, polymer concentration mapping, historical exploitation, revival of vintage wells, recompletion, and perforation optimization and Injection fluid quality control. The down dip (towards aquifer) loss of polymer is controlled by monitoring liquid rates and polymer presence in the offset wells. Also, to assist the water-cut reduction in updip wells, higher drawdown strategy is implemented for polymer-bank movement in the structural highs. Monitoring of injection fluid through down hole sampling is used to ensure desired quality of polymer. Efficient monitoring of the project has resulted in production enhancement from 100tpd to 260tpd with peak production of 300tpd from targeted area. The innovative approach is to execute the project on fast track through hired injection services. This approach has helped in early realisation of oil and generation of data for preparation of expansion of polymer scheme.
Numerical Simulation for Hydrogen Storage and Bio-Methanation
Authors: MousaviMirkalaei Seyed Mousa , Zarei Faraj
Published: June 2023

The potential applications of hydrogen as an energy vector as a part of the solution to decarbonize emissions from use of natural gas and transportation is the subject of much research. Hydrogen storage in the geological subsurface helps to mitigate the effects of fluctuating energy production from renewable energy sources. Nevertheless, there is little comprehensive work on full scale simulation of all the processes associated with the injection, storage and re-producing of hydrogen.

Physical phenomena involved in this process include mixing of hydrogen with native components in the reservoir and potentially cushion gas, ga, relative permeability hysteresis, solubility of various gases into the aqueous phase; effect of hydrogen impurity (e.g., CO2, H2S, CH4) and bio-methanation in the presence bacteria. Numerical simulation can be used for dynamic numerical modelling of the storage when all these complex processes are in action.

Solubility of hydrogen can be modelled using a solubility table, Henry's correlation, or K-values table. The effect of other gases on the geochemistry of the rock and fluid can be studied in detail using chemical and geochemical reaction concepts. The activity of bacteria in an underground hydrogen storage field may result in synthetic methane production. Such reactions can be modelled based on bacterial activity levels using Arrhenius type reactions. The level of biomass activity depends on salinity, temperature and bacterial types and availability of nutrients.

A sub-sector from a North Sea reservoir is used to simulate these processes described and predictions of individual injection/production at various cycles are created. Issues regarding improved monitoring and design of laboratory experiments for future field operations are highlighted. This study shows how simulation can be instrumental in understanding and designing underground hydrogen storage projects, providing predictions of storage volumes, produced gas quality and quantity under various scenarios. The paper also describes the reaction parameters, upscaling, and tuning techniques required for simulation at full field scale.
Analytical Modeling of How Capillary End Effects Impact Time Scale and Transient Data During Steady State Relative Permeability Measurements
Authors: Andersen Pål Østebø
Published: June 2023

The role of capillary end effects on steady state relative permeability experiments is investigated focusing on transient measurements. Analytical solutions are derived for saturation distributions, production, pressure drop and time scales for two important cases: (1) When capillary forces are negligible, Buckley-Leverett principles yield the impact of changing injected flow fraction F or total rate Q. (2) When capillary end effects are significant, but the end effect profile is not reaching the inlet we explore increasing Q. The latter is the main novel contribution.

The steady state saturation profile is only compressed by higher Q at fixed F. This is assumed to hold also transiently to facilitate analytical solutions. The outlet flux follows from the changes in outlet saturation gradient with time, whereby mass balance results in the requested solutions.

In absence of end effects, it takes finite time to reach steady state when F or Q is changed (except for single phase injection). Capillary end effects cause the needed time to be infinite since the solution at late time is exponential. Practically most is produced sooner and a time scale follows from the analytical solutions to reach a specified fraction of production. The injected pore volumes (time) as function of average saturation has a linear term and a logarithmic term. If high Q is applied or it is early time, production is linear with time. The onset of the exponential regime depends on the conditions. Pressure drop increases instantly when Q is increased, but declines afterwards with time (characteristic of end effects) since the end effect is compressed reducing flow resistance. The evolution in pressure drop follows exactly the same profile shape as average saturation. This is the first analytical solution demonstrating how production and pressure drop evolves in response to rate during relative permeability experiments in presence of end effects. Preliminary investigations are presented in this conference paper while more detailed investigations of the model and more theoretical results will be presented in an upcoming journal paper.
Transport of EOR Surfactant in Reservoirs: Impact of Polymer on Apparent Surfactant Inaccessible Pore Volume
Authors: Alves Fortunato Maira , Bekri Samir , Rousseau David , Courtaud Tiphaine , Wartenberg Nicolas
Published: June 2023

Designing chemical EOR processes requires reservoir simulations that need to be backed by a good understanding of the mechanisms at play when injecting surfactant-based solutions in porous media. One of the main challenges is that laboratory coreflood tests often show early surfactant breakthroughs that cannot be easily history matched. Indeed, contrary to polymer macromolecules, smaller surfactant molecules are not supposed to experience the inaccessible pore volume (IPV) effect.

The study's aim was to determine if, in surfactant-polymer flooding, the polymer could influence the transport of the surfactant in such a way that it would not be able to invade a fraction of the pore space. To that end, two multi-steps coreflood tests were performed with cores of outcrop rock in conditions representative of a reference field case. In the first test, the surfactant was injected without polymer and then, after a brine injection flush, with polymer. In the second test, the surfactant was directly injected with polymer.

For both tests, in order to bypass the adsorption effect, the surfactant injected volumes at breakthrough were determined on rocks having their surface already fully saturated by surfactant. Namely, a first surfactant slug was injected in order to fulfill maximum rock adsorption capacity, then, immediately after, a second at a higher concentration of which the breakthrough was potentially influenced by IPV only. The polymer IPV were estimated by the conventional two-slugs method.

In the first test, the result showed that, without polymer, the surfactant accessed all of the pore volume of the core while, in presence of polymer, the surfactant could not access about 2% of the pore volume, which corresponded to the polymer IPV. In the second test, the surfactant was not able to access 12% of the pore volume, which also corresponded to the polymer IPV. These outcomes stand as evidence that the presence of polymer impacts the transport of surfactant, leading it to experience an "apparent" surfactant IPV effect equal to the polymer's one. This suggests that interactions between polymer and surfactant molecules take place at the pore level.

This study illustrates that surfactant transport properties in reservoirs can be more complex than conventionally accounted for in dynamic reservoir simulation. As history-matching of the coreflood essays is needed to build a representative dataset for surfactant-based EOR processes, improvements of the simulation software appear required for cases where IPV cannot be neglected.
Forecasting Low Enthalpy Geothermal Heat Extraction from Saline Aquifers Under Uncertainty
Authors: Bayerl Mathias , Ebner Marcus , Clemens Torsten
Published: June 2023

District heating can be decarbonized by using low enthalpy geothermal heat. In this case study, water from a deep saline aquifer with a temperature of 90-110 °C is produced, heat extracted for district heating and the cold water re-injected into the aquifer. There are substantial subsurface uncertainties in the structure as well as porosity and permeability distribution of the saline aquifer that need to be addressed to optimize heat extraction under uncertainty.

The deep saline aquifer characterization is based on 3D seismic and a limited number of wells. Hence, substantial uncertainty exists in porosity/permeability distribution and dynamic and thermal properties. To address the uncertainty, different geological concepts need to be evaluated and parameter ranges for geostatistical and poro-perm relationships need to be used. To cover the uncertainty range, we constructed 600 geological models all honoring the limited existing data. However, dynamically simulating all the geological models including the ranges for the thermal properties is usually too costly.

We utilize a geo-screening workflow, which selects a subset of representative models based on dynamic (proxy) response, the workflow aims at keeping the same variability of the subset as for the full ensemble. This is achieved via a dimensionality reduction of the problem, by clustering of the models in multi-dimensional space. The centroids of these clusters are selected as representative models used for full-physics simulations to forecast heat extraction under uncertainty. To define a consistent method for selecting a representative subset of geologic realization we simulated the full ensemble and compared it to (i) subsets of different clustering approaches using static (heat in-place) and dynamic (tracer rate & flux pattern) proxy responses and (ii) subset sizes.

The results of the workflow show that the tracer rate is a better metric for the selection of the cluster centroids compared with flux-pattern and in particular heat in place. For this case 20-40 geological realizations were sufficient to cover the uncertainty space for forecasting low enthalpy heat extraction. The suggested workflow allows for addressing the subsurface uncertainty in static and dynamic parameters making use of streamline simulation to reduce simulation costs. The resulting model ensemble can be used for field development planning of low enthalpy heat extraction under uncertainty.