bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Open-hole Diagnostic Fracture Injection Test Results to Regional Stress Interpretation in Bowen Basin Coals
Authors: Scott M.. , Mazumder S.. , Gibson M.. , Probst P.. 
Published: November 2013

Abstract
Diagnostic fracture injection testing (DFIT) has become an established method of well testing in low permeability unconventional reservoirs – particularly in shales and coal seam gas (CSG). As well as providing in-situ measurements of permeability and reservoir pressure, the test allows estimation of the closure pressure (and fluid loss characteristics) for the formation under investigation, which is assumed to be a measure of minimum horizontal stress (σh).
Arrow Energy is currently conducting a wide-scale exploration and well testing programme in the Bowen Basin region of Queensland, Australia, in support of its planned CSG to liquefied natural gas (LNG) project. This programme is mainly focussed on evaluation of formations within the Moranbah and Rangal Coal Measures; these are typically present as thick, low permeability zones.
Traditional Drill Stem Test (DST) and Injection Fall-Off Test (IFOT) results have proven unreliable within such low permeability and under-pressured reservoirs. The limited drawdown generated by DSTs in such formations has historically been an issue for these, and other, reservoirs. Similarly, difficulties have been encountered with regard to the appropriate management of IFOT injection rates in the Bowen Basin coals, which can fracture at very low rates; the resultant diagnostic typecurves needed for analysis of such a "failed" test have tended to introduce an unnecessary level of uncertainty in the results.
At present, the preferred exploitation method for these formations is extended-reach, open-hole, horizontal in-seam wells. As such, very few instances of cased-hole completions are available. Whilst the DFIT technique has previously been widely applied in cased-hole completions, largely due to its prevalence as part of hydraulic fracture stimulation treatment in North America, its application has been extended successfully to open-hole testing as part of this programme. Arrow has to date completed over 140 open-hole DFITs in this region, with an approximately 80% success rate in interpreted parameters with reasonable confidence.
The results of this programme have been incorporated into a basin-wide interpretation of regional stresses and subsurface properties. These results have been used, in combination with Mechanical Earth Models (MEM), to evaluate optimal lateral well orientation, hydraulic fracture treatment design, as well as the mapping of variable stress gradients in an effort to better understand the distribution of permeability trends across different geo-domains.
Fracturing Stimulations Improve Oil Well Performance in Deep Tight Glutenite Reservoirs of the Shengli Oilfield
Authors: Guo Jianchun , Gou Bo , Liu Yuxuan 
Published: November 2013

AbstractThe glutenite oil reservoirs with target stratum between 3400 and 4000m TVD in Shengli oilfield in China are low core permeability within the range of 0.015-0.3mD, which needs to be stimulated to achieve commercial production. These reservoirs have thick pay intervals (gross pay thickness up to 80 meters in some wells), and the massive hydraulic fracturing (MHF) was widely applied with high-rate and large-scale proppant volume since 2007. However, post-fracture production responses showed the MHF weren't always effective in these reservoirs.This paper shows a new technique to stimulate these tight reservoirs with better economic results. It involves two steps including perforation optimization and MHF with proppant density varying. Due to the difference of reservoir properties in the vertical direction, it is required to perforate the pay section within a short interval to ensure that the fracture could penetrate the pay zone. Besides, MHF with low, medium and high density proppant improves the proppant placement in the vertical direction, owing to the difference of proppant falling velocity and the proppant convection among carrying fluid. This method will enhance fracture conductivity comparing with using the same density proppant.The novel technique has been successfully applied to four wells in Y104 Zones of the Shengli Oilfield. The five wells have better post-production than the other three wells with single density proppant. Net pressure matching and post-fracture pressure build-up testing were conducted to evaluate fracture geometry and conductivity. The results of post-fracture analysis and post-production evaluation demonstrate the benefits of this new fracture treatment.This paper presents a field case of a novel stimulation method in tight glutenite reservoir with large thickness. The proposed method solves one of the key fracturing technology difficulties in these reservoirs and improves stimulation performance, effectively promoting the economical development of such oil filed in China.
Coal Seam Gas Field Management: Well Performance and Production Forecasting During Shutdown and Recovery Operations
Authors: Magee S.. , Ogilvie T.. , White C.. 
Published: November 2013

Abstract
This paper presents the results of a study into the post-shutdown recovery behaviour of coal seam gas (CSG) wells and its application to estimating long-term field turndown capacity incorporating the impact of well performance recovery postshutdown.
Queensland, Australia is currently host to a number of CSG to liquefied natural gas (LNG) projects under development. These projects aim to develop Queensland's vast CSG resources to supply domestic and international gas markets. However, the need to build field deliverability prior to the availability of export gas markets presents a significant challenge. CSG wells must be dewatered while gas production may be constrained. The ability to manage and forecast production performance in field turndown scenario is therefore critical.
A study of production data from CSG production interruption events was conducted to determine how wells reacted to turndown of gas production rates. The study considered various production management strategies including partial choking and complete shut in of selected producers.
Implications of the work include identification of criteria for selecting wells that are suitable for long-term turndown, the formulation of operational guidelines for minimising adverse post-shutdown production impacts, and estimation of long-term field turndown capacity through the application of the study results to a field production model.
Best Pumping Practices to Optimize Dewatering in CBM wells: Lessons Learned Developing Raniganj East Field, India
Authors: Pant Himanshu 
Published: November 2013

Abstract
Dewatering is required to remove water from the coal seams so that bottomhole pressure (BHP) is reduced to a critical point where gas will begin to desorb from the coal. Production Data analysis of over 100 wells which includes both vertical and deviated in Raniganj East Coalbed Methane (CBM) field, India indicates that wells were not dewatered continuously. This was mainly due to the fact that the wells go on workover and extended periods of pump downtime result in re-saturation of the cleat and fracture system with water, thereby inhibiting gas production. So starting and stopping pumping resets the hydrostatic back pressure and water saturation profiles to initial conditions in the reservoir while the gas content remains unchanged, thereby requiring more pumping to achieve the previous level of gas production.
An attempt was made to analyze the problem and through production surveillance of past four years production history, various reasons why continuous dewatering was not achieved were pump failures due to high torque, low torque, low pump efficiency and erratic loading conditions. The causes of these pump failures were gas locking, rod/tubing unscrew, stator damage, hole in tubing, plugged intake screens and insufficient motor cooling, etc.
This paper discusses best practices to dewater CBM well after rich experience gained by operator in CBM Raniganj East field from series of trial of artificial lift ESP and PCP pump run in individual wells with design modification by using tailpipes and provides specific recommendations and pump operating parameters to dewater effectively and continuously from both vertical and deviated well.
Influence of Fracturing Fluid and Reservoir Temperature on Production for Complex Hydraulic Fracture Network in Shale Gas Reservoir
Authors: Cohen Charles-Edouard , Weng Xiaowei , Kresse Olga 
Published: November 2013

AbstractProduction from shale reservoirs depends greatly on the efficiency of hydraulic fracturing treatments. Cumulative experience in the industry has led to several best practices in treatment design, which have improved productivity of these reservoirs. Nevertheless, shale reservoirs still bring challenges to stimulation engineers, due to the complex physics involving interactions with natural fractures, stress shadow effects and proppant transport in complex fracture network.One of the challenges regards fluid and proppant selection, in particular, the issue is how to achieve the desired fracturing fluid viscosity inside the fracture for optimum proppant placement into an expanding complex fracture network. The rheological properties of the fracturing fluid depend on its temperature history, hence understanding the temperature distribution in the hydraulic fracture network is a key consideration for a successful treatment and a more accurate fracture prediction.This paper investigates the relation between reservoir temperature, fracturing fluid properties and production through fracturing-to-production simulation workflow. The paper first presents a temperature model implemented into the UFM model, which is a comprehensive complex fracturing simulator for shale reservoirs, accounting for interaction with natural fractures, stress shadow effects, and proppant transport in a complex networks. Based on the fracture geometry, proppant placement, and reservoir properties, a semi-analytical production model UPM is used to estimate the production.This workflow is used to first understand the temperature distribution in the expanding fracture network and understand its evolution as a function of several parameters such as reservoir temperature and rheological properties of the fracturing fluid. Then the associated production forecast provides guidelines on how to achieve optimum proppant and fluid selection based on the reservoir temperature for maximizing production.
The Microseismic Monitoring of Hydraulic Fracturing of a CBM through Simultaneous Use of Downhole Monitoring Tools in the Stimulated and an Offset Well A Case Study – Sanga Sanga CBM, Mahakam Delta, East Kalimantan
Authors: Halinda D.. , Weatherall G. D. , Sesaro A. W. , Nugraha H.. , Collecott D. J. 
Published: November 2013

Abstract
Microseismic hydraulic fracture monitoring uses state-of-the-art downhole seismic tools to record microseismicity from multi-staged hydraulic fracture stimulations in Coal Bed Methane (CBM) completions. This method uses an acoustic method to map in three dimensional space and time the geometry and propagation of fractures during a hydraulic fracture stimulation treatment. The technique has been used for some time in monitoring fracture stimulation in shales and other formations but has had limited use in coals for CBM production.
Microseismic monitoring of hydraulic fracture stimulations in coal seams presents significant challenges as the ductility of coal produces low intensity individual microseismic events which can be difficult to record. Using an offset well to record the microseismic events may result in some uncertainty due to varying degree of attenuation by the coal seam. Additionally, successful recording of fracture stimulations in CBM wells typically requires the monitoring well to be relatively close to the well being stimulated and this often prevents downhole monitoring being applied to these wells. A microseismic monitoring tool that can be placed in the treatment well during the fracture stimulation provides additional information and potentially improves the data quality. Furthermore, two monitoring tools which simultaneously record microseismic events in the in-well and offset wells provide independent data for comparison and increase the quality and confidence of spatial location data.
The Sanga-Sanga Block which is as a very large conventional gas producer in East Kalimantan is now growing as a potential CBM resource. The coal seams in Sanga-Sanga, East Kalimantan are contained in a complex formation of interbedded sandstone, siltstone, carbonaceous shale and coal and have been subject to initial attempts to stimulate the coals for CBM production by hydraulic fracturing.
This paper examines the operational challenges of the simultaneous use of in-well and offset well microseismic monitoring tools in the Sanga-Sanga coal in Indonesia and compares the techniques and overall results and makes recommendations and suggestions for future microseismic coal monitoring.
Comparative Study of Open Hole and Cemented Multistage Vertical Completion Technologies in the Permian Basin
Authors: Keener Brett , Lohoefer Darrell , Snyder D. J. , Ezeldin Saiff 
Published: November 2013

Abstract
The Permian Basin is one of the top five resource plays in the United States and consists of a number of stacked pay zones. Two of these formations, the Wolfcamp shale and Bone Spring (Wolfbone), together deliver a pay zone thickness of 1,000 to 1,500 ft. They are made up of several different layers of organic rich shales intermingled with sandstone and siltstone. Horizontal completions in the shales are just beginning and have yet to be proven; however, operators are successfully exploiting the reserves through vertical wells.
While a mature exploration area, the completion of the thick shale intervals is a new target formation. To date, two vertical completion methods have been utilized to gain access to hydrocarbons: open hole multistage (OHMS) fracturing systems and the conventional cemented liner, "plug and perf" (CLPP) method. This paper compares 30-, 60-, 90-, and 180-day production results from 12 vertical wells in Reeves County, Texas completed with OHMS systems and 33 offset wells completed with the CLPP method. The system details, fracture methods used, as well as the cost and operational differences are discussed.
By comparing these two methods, this paper highlights OHMS as a long-term solution for operators completing vertical wells in stacked pay. The production, operation and cost comparisons of the two completion methods will provide theoretical and practical arguments to assist in designing a completion. The results of this study contribute to the technical conversation of how to economically produce a vertical well.
Study of antioxidant activity of natural food supplements
Authors: Lozova Tetyana 
Published: November 2013

This article describes the results of a study of antioxidant activity of natural food supplements suggested for use in flour confectionery production. Oxidation rate of the model substance - cumene - was measured using a volumetric unit. Diagram of absorbed oxygen amount as a function of time (∆HO2 over t) was built by measuring time in minutes and absorbed oxygen volume in cm3. This diagram was subsequently used to graphically determine the oxidation rate as the slope ratio of the line in specified coordinates. Afterwards, the oxidation rate was measured at a different initiation rate (different azobisisobutyronitrile solution volume), while all other parameters of the experiment remained unaltered. On the basis of the resulting data, diagrams of oxidation rate as a function of initiation rate were built for all investigated substances (both extracts and powders). The study revealed that apian products, including pollen and propolis, as well as kidney bean powder and phytosupplements (leaves of leather bergenia, lime blossom, heartsease, wild chamomile, pepper mint, bog rosemary, and elderflowers), possessed high antioxidant activity. According to the research data, the highest activity was detected in propolis 0.482·20 pollen 0.802 and powdered forms of pepper mint 1.066 leather bergenia leaves 0.937 heartsease 0.385 lime blossom 0.331 and kidney beans 0.323. Relatively lower antioxidant activity was found in powdered bog rosemary 0.242 elderflowers 0.238 and wild chamomile 0.212. (Introduction of the investigated supplements will allow inhibiting oxidation processes in the lipide fraction of foodstuffs, including flour confectionery, to ensure stability of their qualitative characteristics over a longer period).
Medicare-Covered Services Near the End of Life in Medicare Advantage vs Traditional Medicare
Authors: Nicholas Lauren Hersch , Fischer Stacy M. , Arbaje Alicia I. , Perraillon Marcelo Coca , Jones Christine D. , Polsky Daniel 
Published: July 2024

ImportanceFinancial incentives in Medicare Advantage (MA), the managed care alternative to traditional Medicare (TM), were designed to reduce overutilization. For patients near the end of life (EOL), MA incentives may reduce potentially burdensome care and encourage hospice but could also restrict access to costly but necessary services.ObjectiveTo compare receipt of potentially burdensome treatments and transfers and potentially necessary postacute services in the last 6 months of life in individuals with MA vs TM.Design, Setting, and ParticipantsA retrospective analysis of Medicare claims data among older Medicare beneficiaries who died between 2016 and 2018. The study included Medicare decedents aged 66 years or older covered by TM (n = 659 135) or MA (n = 360 430). All decedents and the subset of decedents with 1 or more emergent hospitalizations with a life-limiting condition (cancer, dementia, end-stage organ failure) that would likely qualify for hospice care were included.ExposureMA enrollment.Main OutcomesReceipt of potentially burdensome hospitalizations and treatments; receipt of postdischarge home and facility care.ResultsThe study included 659 135 TM enrollees (mean [SD] age at death, 83.3 [9.0] years, 54% female, 15.1% non-White, 55% with 1 or more life-limiting condition) and 360 430 MA enrollees (mean [SD] age at death 82.5 [8.7] years, 53% female, 19.3% non-White, 49% with 1 or more life-limiting condition). After regression adjustment, MA enrollees were less likely to receive potentially burdensome treatments (−1.6 percentage points (pp); 95% CI, −2.1 to −1.1) and less likely to die in a hospital (−3.3 pp; 95% CI, −4.0 to −2.7) compared with TM. However, when hospitalized, MA enrollees were more likely to die in the hospital (adjusted difference, 1.3 pp; 95% CI, 1.1-1.5) and less likely to be transferred to rehabilitative or skilled nursing facilities (−5.2 pp; 95% CI, −5.7 to −4.6). Higher rates of home health and home hospice among those discharged home offset half of the decline in facility use. Results were unchanged in the life-limiting conditions sample.ConclusionsMA enrollment was associated with lower rates of potentially burdensome and facility-based care near the EOL. Greater use of home-based care may improve quality of care but may also leave patients without adequate assistance after hospitalization.
Auxetic Liquid Crystal Vitrimers with Adjustable Poisson's Ratios Enabled by Topological Rearrangements of Polymer Network
Authors: Zheng Zhiran , Ma Weixin , Li Jiawei , Ma Yaning , Hu Jun , Li Min‐Hui 
Published: July 2024

AbstractMetamaterials feature extraordinary physical properties that break the cognitive limitations of human beings on traditional materials. Auxetic materials and liquid crystal elastomers (LCEs) are representative of typical mechanical and thermal metamaterials. Their combination may introduce some unconventional and counterintuitive performances. Nevertheless, studies on LCEs with negative Poisson's ratio (v) are still rare. Herein, a liquid crystal vitrimer (Poly‐LCE) is developed that is a polydomain main‐chain LCE containing dynamic ester bonds. Its orientation process to monodomain (Mono‐LCE) is greatly simplified by transesterification reaction‐induced topological network rearrangement under mechanical alignment. By optimizing geometric parameters of re‐entrant (R) structures and orientation of liquid crystal units, all samples of R‐Poly‐LCE, R‐Mono‐LCE (//), and R‐Mono‐LCE (⊥) show negative Poisson's ratio (NPR) below 2% elongation (v = −0.22–0 for R‐Poly‐LCE, v = −0.12–0 for R‐Mono‐LCE (//) and v = −0.16–0 for R‐Mono‐LCE (⊥)). Interestingly, R‐Poly‐LCE presents v > 0 within 2%–10% axial elongation, while R‐Mono‐LCE (//) and R‐Mono‐LCE (⊥) exhibit v ≈ 0 under the same elongation. Materials with negative and zero Poisson's ratios are interesting in niche applications. This work develops a simple method to prepare these materials by liquid crystal vitrimers.
Synergistic Interactions Between Co Nanoparticles and Unsaturated Co‐N2 Sites for Efficient Electrocatalysis
Authors: Wang Min , Chen Jialiang , Zhang Shilin , Sun Yuanyuan , Kong Weiling , Geng Lina , Li Yan , Dai Liming , Li Zhongtao , Wu Mingbo 
Published: July 2024

AbstractTransition metal‐nitrogen‐doped carbon (M‐N‐C) single‐atom catalysts exhibit high activity and stability for the oxygen reduction reaction (ORR). Their electronic structure, crucial for ORR intermediates' adsorption/desorption, can be tuned by altering the coordination environment or integrating small metal nanoparticles. However, synthesizing unsaturated M‐NX (x <4) complexes with well‐dispersed nanoparticles is challenging due to reactivity and aggregation issues. In this study, a novel plasma‐assisted in situ thermal reduction strategy is presented to eliminate unstable surface groups for incorporating highly active Co nanoparticles (NPs) and unsaturated coordinated Co‐N2 sites. The unsaturated coordination structure of Co‐N2 regulates the electron cloud density around the Co center, decreasing the energy barrier of the rate‐determining step of 4e− ORR process; while the Co NPs can accelerate the mass transfer during ORR through enhancing O2 adsorption to promote the desorption of *OH and also facilitate the charge transfer. Thus, the remarkable ORR electrocatalytic activity and durability is achieved simultaneously, leading to excellent performance in an aqueous Zn–air battery. The work opens new directions and possibilities for the design and synthesis of efficient and highly selective electrocatalysts for ORR and other redox reactions.