bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety Net Model: Grid-Based HSE Risk Management Integration with Twin Orientations
Authors: Zhao Hongzhan , Yang Yifeng , He Xiaozhen 
Published: December 2021

Abstract
Although companies systematically introduce management systems to improve performance and reduce major accident risks, gaps remain. The mismatch between HSE management system and practical HSE works, line and HSE departments and HSE requirements and actions exerts significant negative impact on the effectiveness and efficiency of HSE management. Under these circumstances, operational management system (OMS), barrier management system (BMS), process safety management and asset integrity management are all studied and applied in an oilfield. The oilfield experienced nine years of development, and the production capacity increased from 4,000 to 400,000 barrels per day. Almost 7,000 people were working in the oilfield during peak time from around 40 countries. During such a development, HSE management was extremely challengeable, and a practical and integrated HSE risk management model was pursued and established.
This paper describes a method of HSE risk management integration called safety net model. The model physically segregates oilfield facilities into individually managed areas or grids. A safety grid is the basic unit of a safety net, and the safety net comprises a series of correlative and interactive safety grids from bottom to up. OMS, HEMP and BMS are the bases of safety net model. Each safety grid complies with the principle of twin orientations: the identification of HSE hazards and assessment of HSE risks and the formulation and substantiation of systematic risk control measures. Specifically, the safety grid has two sets of basic components: hazard, output and time (HOT) and authority, boundary and control (ABC). HOT refers to hazard orientation, and ABC refers to risk control orientation. Two sets of components define attributes of each safety grid. The risk profile is assessed for each grid, in which technical safety and consequence studies are introduced to visually represent at risk locations. Overlaying contours and process boundaries as typical examples result in a simplified model that enables area owners to recognise risks, controls and mitigations so that they can introduce suitable risk reduction measures for safe operations. Through components (HOT ABC) of each safety grid, OMS and BMS are introduced to operational sites and positions directly and easily. Six components are connection points of every safety grid, and all safety grids are knitted to an integrated safety net.
The implementation of safety net model contributes to good HSE performance of the oilfield studied, and the resulting performance is recognised and appreciated by local government and funding parties.
This paper focuses on how to communicate the information in compliance with the principle of twin orientations from safety studies recorded in OMS and BMS to the safety grid. Comprising safety grids, safety net model is an applicable and practical carrier of integrated HSE risk management.
Machine Learning Application to CO2 Foam Rheology
Authors: Iskandarov Javad , Fanourgakis George , Alameri Waleed , Froudakis George , Karanikolos Georgios 
Published: December 2021

Abstract
Conventional foam modelling techniques require tuning of too many parameters and long computational time in order to provide accurate predictions. Therefore, there is a need for alternative methodologies for the efficient and reliable prediction of the foams’ performance. Foams are susceptible to various operational conditions and reservoir parameters. This research aims to apply machine learning (ML) algorithms to experimental data in order to correlate important affecting parameters to foam rheology. In this way, optimum operational conditions for CO2 foam enhanced oil recovery (EOR) can be determined. In order to achieve that, five different ML algorithms were applied to experimental rheology data from various experimental studies. It was concluded that the Gradient Boosting (GB) algorithm could successfully fit the training data and give the most accurate predictions for unknown cases.
Fuel Ammonia from Fossil Energy: Hydrocarbon Utilization for Sustainable Development
Authors: Akai Takashi , Shimouchi Makoto , Miyoshi Keisuke , Okabe Hiroshi 
Published: December 2021

Abstract
Synthetic ammonia from fossil energy can technically be used for power generation. Viewed as hydrocarbon utilization, it enables oil and gas industries to move towards the sustainable development of resources while minimizing their carbon footprint. We present an integrated high-level overview of this concept by highlighting the following key aspects: i) the carbon footprint of the process, ii) the necessity for carbon capture and storage (CCS), iii) power generation from fuel ammonia, and iv) market development. First, the carbon footprint was estimated based on the chemical formulas of the process, which revealed the necessity for CCS for the process to provide cleaner energy. Second, having reviewed these four key aspects, we showed that most elemental technologies comprising this new value chain have already been technically proven. Finally, we discuss and conclude with possible ways towards the commercialization of this value chain.
First Successful Application of Casing in Casing CiC Refracturing Treatment in Shale Gas Well in China: Case Study
Authors: Liu Yaowen , Li Yuanzhao , Zhang Chi , Ming Yue , Xiao Jialin , Han Rong , Wang Zichao , Zhang Jiao , Wu Changhong 
Published: December 2021

Abstract
With active hydraulic fracturing performed since 2012, the Fuling shale gas field in China is one of the largest shale gas fields outside of North America. Recently, a Casing-in-Casing (CiC) refracturing treatment was successfully implemented, resulting in production beyond expectations. This was the first successful application of a CiC refracturing treatment in a horizontal shale gas well in this region, thus providing a new option for refracturing horizontal wells in China.
Bullheading diversion refracturing with diverting balls was previously attempted in this field with high initial production observed; however, production was inconsistent and quickly declined. Therefore, the operator decided to attempt a CiC refracturing method in an understimulated candidate well. This involved installing and cementing 3.5-in. casing in 5.5-in. casing to effectively isolate the perforations, which enabled plugging and perforating operations in the reconstructed wellbore for an effective refracturing treatment. A customized refracturing design integrated the production profile, residual recoverable reserves, and the specific 5.5- × 3.5-in. reconstructed wellbore limitation.
The length of the 3.5-in. casing was optimized to be as short as possible but still cover the original perforations, and high-performance slickwater was used to reduce pipe friction, thus increasing the treatment rate. An engineered breakdown approach was employed for improved fracture initiation. Additionally, more clusters were added between the original clusters and, based on production profile results, some of the original understimulated clusters with little proppant placement were reperforated. To overcome the impact of depleted fractures, a self-degradable particulate diverting agent was used to propagate new fractures, allowing access to new rock to increase total reserve recovery.
The treatment in the reconstructed wellbore was successful, with 21 stages fractured in 12 days, achieving 100% placement of the designed proppant and fluid. A treatment rate of 7 to 12 m3/min from the toe to heel was executed as designed. Test production of 183,800 m3/D was also achieved with a recovery rate of 88.1%. Production has remained consistent and wellhead pressure has remained steady at a high level throughout the first two months of production.
CiC refracturing technology helps overcome common disadvantages experienced with traditional refracturing techniques, such as poorly placed proppant and fluid and inconsistent production. CiC refracturing not only allows exploitation of bypassed reserves from original fractures, but also allows precise stimulation of new rock to obtain the highest reserve recovery. The successful implementation of this case study illustrates the reliability of CiC refracturing technology and provides valuable experience to be used during future regional horizontal well refracturing.
Geomechanical Approach in Classification of Borehole Failures in Fractured Carbonates of Boca De Jaruco Field
Authors: Norkina Anna Vladimirovna , Simakov Iaroslav Olegovich , Petrakov Yuriy Anatoljevich , Sobolev Alexey Evgenjevich , Petrashov Oleg Vladimirovich , Soloviev Alexey Vitalievich 
Published: December 2021

Abstract
This article is a continuation of the work on geomechanically calculations for optimizing the drilling of horizontal wells into the productive reservoir M at the Boca de Haruco field of the Republic of Cuba, presented in the article SPE-196897.
As part of the work, an assessment of the stress state and direction was carried out using geological and geophysical information, an analysis of the pressure behavior during steam injections, cross-dipole acoustics, as well as oriented caliper data in vertical wells.
After the completion of the first part of the work, the first horizontal wells were successfully drilled into the M formation. According to the recommendations, additional studies were carried out: core sampling and recording of micro-imager logging in the deviated sections.
Presence of wellbore failures at the inclined sections allowed to use the method of inverse in-situ stress modeling based on image logs interpretation.
The classification of wellbore failures by micro-imager logging: natural origin and violations of technogenic genesis is carried out. The type of breakout is defined. The result of the work was the determination of the stress state and horizontal stresses direction. In addition, the article is supplemented with the calculation of the maximum horizontal stress through the stress regime identifier factor.
Recovery Factor Improvement; A Success Story of Improving 10% of RF in Greater Natih Reservoirs, North of Oman
Authors: Sheibani Hilal , Wulandari Ratih , van Gilst Roeland , Al Lawati Hawraa , Abri Al Mutasem , Maqbali Humaid , Zaabi Fatma 
Published: December 2021

Abstract
Recovery Factor Improvement (RFI) is a process to check the hydrocarbon production efficiency by incorporating the actual static and dynamic field data, as well as the way how the field being operated. This has been a common process within Shell's portfolio since 2018 (Ref; Muggeridge et al., 2013 & Smalley et al., 2009). The approach has been developed to stimulate the identification of new opportunities to increase the recovery from the existing fields and to aid the maturation of these opportunities into the Opportunity Realization Process.
There are four (4) factors that affected overall reservoir recovery factor, they are: Pressure efficiency; related to which pressure can be reduced in the reservoir as dictated by the relevant facilities and wells.Drainage Efficiency; the proportion of the in-place hydrocarbon that is pressure-connected directly to at least one producing well on a production timescale.The "secondary pay" efficiency; takes into account the volumes of poorer quality rock in which the gas remains at pressure above the lowest pressure just outside the wellbore (Pf) when the reservoir is abandoned.Cut-off Efficiency; the proportion of hydrocarbon that is lost due to non-production of the tail.This approach was applied in the dry gas Natih Reservoir fields in the PDO concession area. Before the implementation of RFI, the average recovery factor for Natih was around 70%. This was considered low for a homogenous-dry gas reservoir. The targeted Natih fields were benchmarked against each other with a total of 11 fields with similar reservoir properties. Post the benchmarking exercise, the expected field recovery factor is approximately ~90-93%. The team managed to map out the opportunities to achieve the targeted RF and identified the road map activities. The activities are mainly related to: production optimization: retubing, re-stimulation reduce drainage: infill drilling, horizontal well reduce the field intake through compression
The outcome of the mapping was then further analyzed through integrated framework to be matured as a firm-project. The new proposed activities are expected to add around 9% additional recovery to the existing fields. There will be a remaining activities which will be studied in the future, example infill wells and intelligent completions. These will close the gap to TQ and add other addition RF of 11-13%.
As conclusion, the RFI was seen as a structured approach to better understanding the field recovery factor based on the integrated surface and subsurface data with a robust analysis to trigger opportunity identification linked to RFI elements. It is similar concept as sweating the asset by generating limit diagram for each recovery mechanism & the road map to achieve the maximum limit. This paper will highlight the Natih Fields RFI analysis, highlighting the key learning and challenges.
Smart Retarder for Cementing Systems with Accelerated Set and Gel Strength Properties with Potential for Improved Operational Safety
Authors: Rodrigues Klin , Dos Santos Auribel , Oskarsson Hans , Jankowski Szymon , Ferm Paul 
Published: December 2021

Abstract
Cement retarders available in the market include the traditional lignosulfonates and synthetic copolymers. Commonly, lignosulfonates lack batch to batch reproducibility which hinders formulation consistency. Both lignosulfonates and synthetic polymers will retard the set of cement. However, their chemistry dictates that they also slow down setting time which increases waiting on cement time, thus increasing rig costs. This paper proposes a new smart cement retarder that overcomes these traditional negatives.
A number of polymers were designed and synthesized aiming for a chemical able to retard the set of cement while also acting as an accelerator once the cement slurry was in place. These polymers were tested for cement retardation performance using a high-pressure high-temperature (HPHT) consistometer. Static Gel Strength Analyzers (SGSA) measurements were used to determine compressive strength development as well as static gel strength development while curing under downhole temperature and pressure conditions.
The new smart cement retarder delivers cement retardation in the 125 - 350°F temperature range and can be used at higher temperatures using a co-retarder. This unique material delivers an accelerated set and attains 500 psi compressive strength very quickly which minimizes waiting on cement time. In addition, this new retarder builds static gel strength rapidly and minimizes gel transition time. Upscaling to field application, the top of the cementing column takes the longest to set. By having this inbuilt accelerator into the system, it allows the top of the column to set as fast as possible gaining the needed compressive strength at the weakest point of the cement column. This should ensure the quality of the cement job in comparison with conventional retarders with significant operating cost savings.
The new smart cement retarder will simplify cementing formulations due to its flexibility in dosage range of the retarder within the slurry and improve the quality of the cement jobs. As a result, the proposed smart cement retarder can help with minimizing risk of failures during production and possibly improving safety.
Decarbonization and Improved Energy Efficiency Using a Novel Nanocomposite Surface Treatment
Authors: Nakatsuka Matthew , Marco Basile , Thapa Sumil , Ventura Alexander , Pascolini Osvaldo , Pellicciotta Luca , Veedu Vinod 
Published: December 2021

Abstract
Fouling of heat exchanger equipment through the formation and attachment of hard scale, microbially induced corrosion (MIC) products, or particulate erosion is a serious challenge to reliable production in the oil and gas industry. Exchangers which become fouled in this way perform 15-30% worse than their rated ability, requiring either constant intervention to clean away biofilms, continuous injection of biocides and corrosion inhibitors, or the regular plugging of tubes to prevent leaks, representing a significant operating expense and billions of dollars in lost production time.
When an exchanger is unable to provide sufficient heat due to tube fouling, additional sources of heating must be utilized to make up for this deficit and to ensure that facility processes remain within design allowances. This need for supplemental heating is a significant source of carbon emissions in the industry and represents a significant obstacle towards decarbonization efforts. However, it also represents an economically attractive way to simultaneously lower emissions while also lowering a producer's cost per barrel.
This work describes an alternate strategy to control and prevent fouling in heat exchangers, through the one-time application of an omniphobic (water- and oil-repelling) nano-surface treatment. Once applied to a heat exchanger, the extremely smooth and low-surface energy material greatly reduces the ability of MIC-causing bacteria to deposit and adhere to the surface. Because it imparts functionality to the surface itself, rather than simply function as a physical barrier, it enables long lasting protection which was validated under laboratory conditions in a pressurized autoclave, as well as two pilot demonstrations.
Results from both the laboratory and field evaluations of the treatment's promise showed that treated surfaces showed a corrosion rate over 36-times lower when compared to untreated surfaces, while also completely arresting the formation of corrosion pitting, tube fouling, and erosion of the tube interior. These field-validated results were then applied to the observed heating deficit of a proposed deployment site, resulting in calculated carbon emissions savings of up to 17,000 Tons CO2 per year.
Experiment on Mechanical Properties and Seepage Capability of Deep Tight Sandstone Under True-Triaxial Stresses Environment
Authors: Li Jiaying , Qi Chunyan , Gu Ye , Ye Yu , Zhao Jie 
Published: December 2021

Abstract
The characteristics of seepage capability and rock strain during reservoir depletion are important for reservoir recovery, which would significantly influence production strategy optimization. The Cretaceous deep natural gas reservoirs in Keshen Gasfield in Tarim Basin are mainly buried over 5000 m, featuring with ultra-low permeability, developed natural fractures and complex in-situ stress states. However, there is no comprehensive study on the variation of mechanical properties and seepage capability of this gas reservoir under in-situ stress conditions and most studies on stress-sensitivity are conducted under conventional triaxial or uniaxial stress conditions, which cannot truly represent in-situ stress environment. In this work, Cretaceous tight sandstone in Keshen Gasfield was tested under true-triaxial stresses conditions by an advanced geophysical imaging true-triaxial testing system to study the stress-sensitivity and anisotropy of rock stress-strain behavior, porosity and permeability.
Four groups of sandstone samples are prepared as the size of 80mm×80mm×80mm, three of which are artificially fractured with different angle (0°,15°，30°) to simulate hydraulic fracturing. The test results corresponding to different samples are compared to further reveal the influence of the fracture angle on rock mechanical properties and seepage capability. The samples are in elastic strain during reservoir depletion, showing an apparent correlation with fracture angles. The porosity decreases linearly with stress loading, where the decrease rate of effective porosity of fracture samples is significantly higher than that of intact samples. The permeabilities decrease exponentially and show significant anisotropy in different principal stress directions, especially in σH direction.
The mechanical properties and seepage capability of deep tight sandstone are successfully tested under true-triaxial stresses conditions in this work, which reveals the stress-sensitivity of anisotropic permeability, porosity and stress-strain behavior during gas production. The testing results proposed in this paper provides an innovative method to analyse rock mechanical and petrophysical properties and has profound significance on exploration and development of tight gas reservoir.
First Case Study for Litho-Petro-Elastic AVA Pre-Stack Inversion for Complex Tight Reservoirs Miocene – Upper Cretaceous in East Onshore Abu Dhabi
Authors: Obaid Khalid , Noufal Abdelwahab , Almessabi Abdulrahman , Abdelaal Atef , Elsadany Karim , Gofer Edan , Aly Omar , Nyein Glen , Mukherjee Anubrati 
Published: December 2021

Abstract
This study summarizes the efforts taken to provide reliable reservoir characterizations products to mitigate seismic interpretation challenges and delineation of the reservoirs. ADNOC has conducted seismic exploration activities to assess Miocene to Upper Cretaceous aged reservoirs in East Onshore Abu Dhabi. The Oligo-Miocene section comprises of interbedded salt (mainly halite), anhydrite, limestones and marls. Deposited in the foreland basin related to the Oman thrust-belt. Ranging in thickness from nearly 1.5 km in the depocenter to almost nil on the forebulge located to the west of the studied area.
The well data based geological model suggests that initially porous rocks (presumably grain-supported carbonates) encompassed polyphase sulfate cementation during recurrent subaerial exposure in which pores and grains were recrystallized sometimes completely too massive, tight anhydrite beds. This heterogeneity of the complex shallow section showing high variation of velocity impact seismic imaging, and interpretation to model the stratigraphic/structural framework and link it with reservoir characterization. Hence, ADNOC decided to conduct a trial on state-of-art technique Litho-Petro-Elastic (LPE) AVA Inversion to mitigate the seismic interpretation challenges and delineate the reservoirs.
The LPE AVA inversion provides a single-loop approach to reservoir characterization based on rock physics models and compaction trends, reducing the dependency on a detailed prior the low frequency model, Where the rock modelling and lithology classification are not separate steps but interact directly with the seismic AVO inversion for optimal estimates of lithologies and elastic properties. The LPE inversion scope requires seismic data conditioning such as CMP gathers de-noising, de-multiple, flattening and amplitude preservation, in addition to detailed log conditioning, petro-elastic and rock physics analysis to maximize the quality and value of the results.
The study proved that the LPE AVA Inversion can be used to guide seismic interpreters in mapping the structural framework in challenging seismic data, as it managed to improve the prospect evaluation.