bluuebunny/crossref_metadata_2025_split huggingface dataset:
Repurposing Idle Oil and Gas Wells for Large-Scale Subsurface Energy Storage in Saline Aquifers
Authors: Krishna Ashok , Shenoy Ram , Jha Birendra , Liu Zhongqi , Paul Donald L. , Ershaghi Iraj 
Published: April 2022

Abstract
The continued adoption of intermittent renewable power generation sources, such as wind or solar requires large-scale, long-duration energy storage to buffer the intermittency of renewable power sources so as to supply 100% dispatchable power whenever it is demanded. When required for durations greater than 24 hours and at large (500+ MW) scale, current energy storage solutions offer only 4-10 hours storage, becoming prohibitively expensive, as in the case of batteries, or very site-constrained and environmentally challenged Pumped Hydro systems (PHS). A Hyper-Scale Energy Storage (HSES) solution using repurposed idle oil & gas wells to store energy in subsurface saline aquifers is presented here. The screening criteria for the selection of suitable subsurface saline aquifers that can be accessed via idle oil and gas wells is discussed. Repurposing idle wells or subsurface energy storage could provide an alternative to costs associated with traditional well abandonment and remediation. Repurposing idle wells could also provide a means for reducing current methane emission profiles. The proposed zero-carbon storage solution offers energy storage durations much longer than available alternatives, making possible a national grid with 100% variable renewable generation from solar and wind, and the retirement of many fossil generating plants.
Conventional Compressed Air Energy Storage (CAES) plants operate with low efficiency and use salt caverns. Scaling up for a longer duration becomes expensive and site-constrained as it is contingent on the availability of large volume salt caverns. They use natural gas fuel to heat expanding air through gas turbines for power generation and thus are not a zero-carbon operation. While the current focus is on the approximately 38000 idle wells in California oil and gas fields, the proposed process and associated storage system could well apply broadly to the many US and global petroleum operations with large inventories of aging and idle oil and gas wells.
Real Time Mud Flow Rate Calibration to Mitigate Wellbore Instability Challenges in Shale Formations
Authors: Alsubaih Ahmed Ali , Robello Samuel 
Published: April 2022

Abstract
Cutting transportation is one of the most crucial drilling problems during penetrating shale formations juxtapose well stability events. It is equally important the drilling team should consider real time monitoring to the flow rate based on hole problem in the shale formation being drilled. Several authors have conducted extensive analysis to optimize the optimum flow rate in real time bases but the problem has not been fully understood especially when it comes for hole enlargement. Due to its simplicity, drilling engineers usually use deterministic method to control cutting transportation. The method adjusts drilling parameters such as pump flow rate (FR), plastic viscosity (PV), yield point (YP), Rate of penetration (ROP), revolution per minute (RPM), and mud weight (MW). The past practices of this method did not show significant improvements in well stability's events. This paper will introduce a numerical model to quantify the most sensitive hole cleaning parameters. For that purpose, the research will examine the real time modification of the drilling parameters based on rock fragments for sufficient hole cleaning. A tornado chart has been constructed based on hole enlargement considering hole cleaning, mud weight, elastic viscosity, yield point, ROP, RPM, and well angle. A Monte Carlo simulator has been utilized to reduce the uncertainty in hole enlargement during calculating the optimum parameters. 1000 trials have been fitted to the model based on the range of 0.5 to three times of hole enlargement. This method can articulate a huge impact on selecting drilling parameter based on the probabilistic evaluation. Drilling data from sixty wells in Southern Iraq have been investigated and they revealed a significant augment in none productive time because of the inappropriate selection of drilling parameters deteriorates well stability. This paper develops an engineering method to ensure sufficient lifting capacity to the rock cuttings while drilling an instable formations and it offer acceptable range of flow rate, yield point and elastic viscosity based on the severity of wellbore instability. The traditional wellbore stability is not panacea to wellbore problems without considering wellbore condition. Thus, a combination of all the interstice and extrinsic factors can be crucial in order to drill a well safely and cost effectively.
Direct Contact Steam Generation Reduces Carbon Intensity
Authors: Kay Brian , Hartley Thomas , Zhang Stella , Doig Lisa 
Published: April 2022

Abstract
Steam for enhanced oil recovery is typically generated using Once-Through-Steam-Generators (OTSG) produced at large central facilities with the steam then pipelined to each injection well. As much as 50% of the energy can be lost before it reaches the well bore with the combustion emissions vented to atmosphere.
Direct Contact Steam Generation (DCSG) injects both steam and hot combustion flue gases into the reservoir. Oil production is increased by reducing oil viscosity through heat while repressuring the reservoir with flue gases and improving miscibility with the CO2 that remains in the reservoir. This combination greatly improves the Steam-Oil-Ratio (SOR) for increased oil recovery as well as delivering environmental benefits related to reduced water requirements and lower emissions resulting in a much lower carbon intensity. DCSG water requirements are 11% less than OTSG methods as water is created by the combustion process, this water is then injected into the reservoir rather than lost to the atmosphere. As most of the DCSG process emissions are indirect, emissions can be further reduced by as much as 30% with the use of low carbon intensity grid electricity for compression.
Pilot results show that DCSG used less water, with 70% of the CO2 retained in the formation. Lower SOR and CO2 retained in the reservoir demonstrates lower carbon intensity relative to OTSG.
DCSG offers heavy oil operators a novel, viable, method to economically extract currently uncoverable reservoirs at a lower carbon intensity than traditional methods.
Evaluating the Pressure-Dependent Equivalent Permeability Evolutions for Shale Matrix: Experiments and Modeling
Authors: Yang Yun , Liu Shimin , Liu Ang 
Published: April 2022

Abstract
The ability to model and predict matrix permeability changes during reservoir depletion is critical for accurate analysis of long-term production performance in unconventional gas reservoirs (UGRs), including shale gas and coalbed methane reservoirs. Yet, flow quantification in the nanoporous matrix is still challenging due to the complex pore structure and morphology. To understand the pressure-dependent matrix permeability evolution, this study conducted laboratory permeability measurements using pulverized samples. Equivalent permeability was estimated from the pressure decay profile for the Devonian shale sample. A novel experimental system, a differential volumetric unit, has been established and applied to capture the accurate transient gas flows for the shale sample. The measured permeability of shale exhibited overall decreasing trends with pressure depletion. Due to the presence of slip flow and Knudsen diffusion, low-pore-pressure data did not follow the same decline trend fitted by high-pore-pressure data as observed in the shale sample. This study also utilized methane as the invasion fluid to examine the adsorption effect on matrix permeability, whose value could be up to 40% lower than permeability without correction for adsorption because of the condensation of adsorbed phase at pore surface occupying available pore space. Since these tight rock matrixes are composed of micro- and nanopores, matrix permeability is primarily related to pore structure (e.g., the pore size distribution, porosity and tortuosity). Low-pressure N2 adsorption was conducted to characterize the complex pore structure of the Marcellus shale sample. A multimechanic model was proposed to predict the pressure-dependent matrix permeability based on pore structure information and investigate the effect of gas adsorption on apparent permeability. This model has successfully linked the realistic, complex pore structure with the pressure-dependent matrix permeability of shale and coal. The proposed model could be coupled into the commercially available simulator to forecast long-term production profiles for UGRs wells.
A Novel Environmentally Friendly, Cost Effective Method for Hydraulic Fracture Geometry Evaluation: Cased Hole Cross-Dipole Data
Authors: Al Isaee Omar Mohammed , Smirnov Dmitrii , Al Hadhrami Abdullah , Mahrooqi Alkhattab , Shabibi Hilal , Sayapov Ernest , Moiseenkov Alexey , Kaabi Saqer 
Published: April 2022

Abstract
Cased hole cross-dipole acoustic acquisition is a novel environmentally friendly and cost-effective method for hydraulic fracture geometry evaluation. This method eliminates the environment contamination by the radioactive tracers and replaces the costly micro-seismic monitoring system.
Radioactive tracer usage has a risk of pollution associated with improper storage, transportation and use of low dose, short half-life radioactive materials. The new technology eliminates the risk of having radioactive contamination during hydraulic fracturing operations. The sonic anisotropy measurements comparison taken before and after the hydraulic fracturing job allows estimating differential acoustic anisotropy and enables hydraulic fracture geometry evaluation. The method replaces radioactive (R/A) tracers and eliminates any risk of radioactive contamination, high cost, and complex hydraulic fracturing microseismic monitoring (HFM) operation which requires well monitoring. The method was successfully implemented in Greater Birba Cluster in the Sultanate of Oman, during hydraulic fracturing operations in 2020. Results were compared and validated with radioactive tracers, spectral noise log and microseismic monitoring data. This was a first use of sonic anisotropy measurements for fracture geometry evaluation in Petroleum Development Oman (PDO) and the Gulf Cooperation Council (GCC) region.
In terms of Zero radiation Risk: The common R/A Tracers Antymoniy-124, Iridium-192 and Scandium-46 have a half-life from 60 to 83 days. One curie of these tracers will give a dose rate of 480 -1090 mR per hour at a meter. Tracers are compounds with both internal and external exposure hazards to humans; they emit highly energetic gamma/beta radiation which can cause localized damage if ingested, inhaled or absorbed by the skin. Externally, both beta and gamma radiation can cause localized damage to exposed areas. Eliminating operations with these materials reduces risk of exposure hazard for field personnel to zero.
Efficient and Consistent Sidetracking Operations Lower Production Costs While Minimizing Footprint in Shallow Re-Entry Wells
Authors: Emelander Tom 
Published: April 2022

Abstract
In California, re-entry projects to sidetrack existing wells are a common method of accessing reserves while avoiding the process of obtaining permits for drilling new wells. Utilizing existing assets reduces the cost associated with surface footprints and partial well construction and lowers environmental impact. Recent improvements in consistency and efficiency during casing exit operations have enabled operators to minimize spend and well construction time, which makes these sidetracks more economical.
The majority of offshore and onshore re-entry wells in California require that casing exit operations be performed at shallow depths of less than 2,500 ft. Installations closer to the surface can be challenging with regard to weight limitations and an increased likelihood of a poor cement bond on the backside of casing in soft formations. Smaller workover rigs with limited torque output on land operations can also add a layer of complexity. Through collaboration during the planning process, modifications to off-the-shelf technology, and application-specific procedure adjustments, single-trip success rates and milling times have dramatically improved in the past few years.
An analysis of data from one hundred consecutive shallow casing exits from 2016 and 2017 in California shows that single trip performance was lower there compared to the average in other areas of the US and world. After an in-depth look at the installs, it was determined that a change in mill dressing and slight increase in torque output on some of the rigs could make operations more consistent and efficient. One hundred consecutive exits from 2018 to 2021 in the same geography and depths prove the implementations to have a notable improvement. In fact, the single-trip success rate improved from 84 percent to 100 percent and average mill times decreased by 35 percent.
This paper shows that reliable and efficient casing exit installations are ongoing in challenging shallow re-entry applications. This discovery provides the industry an opportunity to replicate these successes in similar assets where new drills are either uneconomical or undesirable.
A Comprehensive Review of RTA/DCA Methods in Unconventional Reservoirs
Authors: Aydin Hakki , Boppano Narendra , Yurukcu Mesut , Liu Shuhao , Yegin Cengiz , Temizel Cenk 
Published: April 2022

Abstract
Rate Transient Analysis (RTA) and Decline Curve Analysis (DCA) have been utilized as critical tools in calculation of oil production for unconventional reservoirs. Due to the ultra-low permeability of these wells, time scales of flow regimes are different than those of conventional reservoirs, where transient regimes last longer, and the decline behaviors change, factors that make forecasts more challenging. There are several RTA/DCA methods for originally developed conventional and unconventional reservoirs including recent techniques. However, petroleum engineers require a single comprehensive reference where RTA/DCA methods are covered with detailed explanations, as well as an outline of their assumptions, limitations, strengths, and appropriate applications. This study tackles the lack of such a resource, delivering a comparative work that includes theory, practice, and examples.
A comprehensive literature review has been carried out to investigate the RTA/DCA methods for unconventional reservoirs in detail, explore the newest techniques and the different methods repurposed from existing conventional approaches with a longer history of use, robustness, and applicability. We also provide a detailed account of the limitations and the advantages of different methods when applied to different types of fields. We achieve this by developing real field applications in different parts of the world and discussing the challenges and opportunities of each RTA/DCA method for a particular type of well.
RTA/DCA methods have shown to be a practical tool for both conventional and unconventional reservoirs, and can be applied across many types of oil and gas wells throughout the world. This work shows the parameters best suited for a successful application of these recovery methods in unconventional sites. Moreover, the evidence collected here will serve as a resource for engineers looking for a summary of the most important criteria to be followed in order to apply oil recovery methods in new wells. We expect that future oil production in unconventional reservoirs can be boosted by the results provided in this work.
The novelty of this study centers on the lessons drawn from the real-world applications of RTA/DCA methods like Duong's, or stretched exponential decline, to recover oil from unconventional reservoirs. We expect these lessons to define the proper utilization of distinct methods for different reservoirs in future studies and the field.
Efficient Reservoir Management with a Reservoir Graph Network Model
Authors: Guo Zhenyu , Sun Wenyue , Sankaran Sathish 
Published: April 2022

Abstract
Efficient reservoir models are more desirable for fast-paced reservoir management. Moreover, due to the complexity of flow underground, it is also essential to capture the most fundamental physics for model reliability. Though running fast, pure data-driven models often suffer from the issues associated with interpretability, physical consistency, and ability to forecast. On the other hand, we have used full-physics simulation models to mimic and investigate hydrocarbon systems for over several decades. However, considering its infrequent model updates related to high model complexity, it is a big challenge to manage reservoirs using full-physics models in short cycles. The objective here is to propose an approach that blends reservoir physics with data-driven models to fit in the framework of dynamic reservoir management.
We propose to use a reservoir graph network (RGNet) modeling approach based on diffusive time-offlight (DTOF) concept to simulate reservoir behaviors. By assimilating field observation data (such as pressure and rates), an RGNet model can be used for future predictions, scenario studies and well-control optimizations. By discretizing DTOF of a three-dimensional system with multiple wells, RGNet simplifies the system into a graph network represented by a set of one-dimensional grid blocks that significantly reduces the system complexity and run time. RGNet can also handle multiple flow problems with various types of physics. In this work, we investigate multiple grid connectivity methods to develop reliable and parsimonious models for large scale systems. In addition, we propose a more robust method to assimilate static pressure data, when available.
We applied the proposed approach to a synthetic example. Two different history matching algorithms, the ensemble smoother with multiple data assimilation (ES-MDA) and an adjoint-based method, are compared. While ES-MDA provides the capability for uncertainty analysis, an adjoint-based method generally requires fewer simulation runs to generate a posterior model. With the proposed gridding methods, RGNet model calibration can be achieved without system redundancy and spurious longdistance well-connectivity. Also, by using a more stable pressure matching technique, we show that pressure data are better matched and reservoir volume is accurately characterized.
RGNet provides a novel hybrid physics and data-driven reservoir modeling method to fit in closed-loop reservoir management. As RGNet models are combined with fundamental flowing physics, the calibrated model parameters are easy to interpret and understand. An RGNet model runs with far less computational cost than required by a full-physics model, which allows it to be a more practical solution to history match, predict and optimize real assets.
Chemical Flood with a Single Surfactant
Authors: Panthi Krishna , Mohanty Kishore K. 
Published: April 2022

Abstract
The goal of this work is to develop alkaline-surfactant-polymer (ASP) formulations for a shallow, clayey sandstone reservoir. Commercially available surfactants were used in the phase behavior study. The gas-oil-ratio (GOR) was low; the phase behavior and coreflood study was conducted with the dead oil. The surfactant formulation systems were tested in tertiary ASP core floods in reservoir rocks. Many surfactant formulations were identified which gave ultralow IFT, but the formulation with only one surfactant (at 0.5 wt% concentration) in presence of one co-solvent was selected for corefloods. The cumulative oil recovery was in the range of 94-96% original oil in place (OOIP) in the corefloods. The surfactant retention was low (0.15 mg/gm of rock) in spite of the high clay content. The study showed that 0.5 PV of ASP slug and 2700 ppm of the polymer were required to make the flood effective. The use of alkali and preflush of the soft brine helped minimize surfactant retention.
Whole Cell of Pure Clostridium Butyricum CBT-1 from Anaerobic Bioreactor Effectively Hydrolyze Agro-Food Waste into Biohydrogen
Authors: SHAH TAWAF ALI , Zhihe Li , Zhiyu Li , Zhang Andong , Lu Di , Fang Wang , Xuan Han 
Published: April 2022

Abstract
Recycling organic waste and converting them into renewable energy is a promising route for cleaning environment and effective industrial reactions. This study targeted to isolate a pure anaerobic culture with potential to hydrolyze different biomass and bio-H2 production. For this, a sample of full-scale anaerobic digester, fed with a mixture of biomass was inoculated on Reinforced Clostridial Medium (RCM) in strict anaerobic conditions. An anaerobic Clostridium Butyricum CBT-1 strain was isolated, identified from morphological and 16S rRNA sequence. The strain expressed amylase, cellulase and peroxidases activities. CBT-1 efficiently showed fast growth rate of 3.10 OD/600nm after 72 hours incubation time on Azure B and crystal violet dyes. The strain exhibited 82.4% and 78.5% decolorization of Azure B and crystal violet dyes respectively. In batch fermentation experiment, the CBT-1 produced highest of 3.06, 2.67 and 2.46 mol/mole H2 yield from glucose, starch and cellulose respectively. Whereas, the CBT-1 showed low 0.43 mol/mole from untreated rice straw, and comparatively high H2 yield of 1.91 and 2.01 mol/mole rice straw hydrolysate and kitchen waste respectively. The cumulative volumetric yield of H2 was 358.15, 300.8 and 294.5NmL/gSub from glucose, starch and cellulose respectively. Similarly, the cumulative H2 volume was 76.7, 184.4, 237.2 NmL/gVS from untreated rice straw, rice straw hydrolysate and kitchen food waste. This study emphasizes the prospects to find similar robust anaerobic culture for hydrolyzing complex biomass. Such strains could be used as standard co-inoculum for bio-H2 and biocatalyst for commercial scale applications.
Characterization of sub-cycle Electromagnetic pulse by long-life traces of wavefronts sampled in attosecond-level step
Authors: Lin Hai , Liu Chengpu 
Published: April 2022

Abstract
Current methods of characterizing electromagnetic(EM)-pulse can be divided into two classes,one is based on photons replica of the EM-pulse under test and the other on electrons replica.Methods in first class, such as interferometry and spectrography, are difficult to be competentfor characterization of EM-pulse with attosecond(AS)-level duration due to too short duration ortoo broad bandwidth. Methods in second class, such as streak camera method, is competent butdemands the pulse to have a peak strength high enough for efficiently producing X-ray photons.We propose a simple, universal method without special demand on the peak strength. It usesconventional optics method to sample, in AS-level step, wavefronts of the EM-pulse under test.Phase information carried by each sampled wavefront is fixed into, as a long-life trace, solid-statecircuit and hence allow recording raw measurement data to be conducted over a feasible longer timescale.