bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reservoir Drilling and Completion Best Practices: Well Productivity Assessment Applying Drill in Fluid, Chelant/Enzyme Breaker System and Stimulation Design on Onshore Well BHT Scenario in Brazil
Authors: Leal Adelson Belizário , Barroso Alexandre Lima , Miranda Xandel , Flores Luis , Medeiros Gutembergue , Marcelino Cleuton , Moranezi Lillian , Pereira Rogério Amadeu , Oliveira Filipe Silva , Cândido Herick Bulhões 
Published: April 2019

Abstract
A significant number of horizontal wells have ultimately proven to be engineering failure impacting the productivity result negatively. This paper will discuss an approach of a suitable non-damaging fluid designed to drill a depleted and high BHT (Bottom Hole Temperature) horizontal well located on the Sergipe Basin, Northeastern Brazil. Particularly, the application of a customized Chelant /Enzyme filter cake Breaker System and potential Formation of emulsion was evaluated presenting results here.
The performance of the fluid loss and viscosifier additives was then evaluated for high BHT. Finally, the necessity of the use of emulsion preventer was evaluated, since tests showed emulsion formation between RDF fluid loss and reservoir oil. The last step was to formulate RDF Breaker. These wellbore productive fluids are designed to attack specific RDF mudcake components; an enzyme and a chelant with the functionality to consume the starch and calcium carbonate components, respectively, minimizing reservoir damage.
The results show that the temperature stabilizer displays favorable interactions with polymers when exposed to high temperatures, above 240 °F. The hydroxypropyl starch was selected as the fluid loss controller because it presented lower API filter volume under conditions of 243 ° F for 48h. Under the same conditions between the xanthan gum analyzed for the viscosifying additive, one showed better rheological results. An emulsion preventer selected displayed good results in the action against formation of emulsion of the API filter and the oil. Breaker effectiveness was proven with the Return Permeability Test performed, which showed acted as a mudcake remover formed by the RDF.
Novel HVDC Power Transmission Architectures for Subsea Grid
Authors: Ray Anindya , Rajashekara Kaushik , Krishnamoorthy Harish 
Published: April 2019

Abstract
Subsea electrification is envisaged as one of the key building blocks of deep-water oil and gas (O&G) production. Present power transmission and distribution (T&D) schemes almost exclusively employ high voltage AC (HVAC) technology to drive the electrical processing units in the seabed, such as pump and compressor motors. Although HVAC transmission is reliable and simple to control, it exhibits a serious drawback with increasing step-out distance in terms of high reactive power requirements and reduction in peak power transfer capability for the subsea transmission cable. Moreover, most of the existing subsea T&D architectures employ a hub-and-spoke architecture with a single power receiving node. As a result, these systems are vulnerable to single-point failure.
In order to address the above issues, two novel subsea architectures, based on high voltage DC (HVDC) transmission, are proposed in this paper. HVDC offers a significant advantage over HVAC systems for longer transmission distances with additional power processing units embedded in the system. Both these architectures employ a subsea DC distribution bus concept to supply multiple subsea loads which represent current scenario of increasing subsea consumers. The performance of the proposed architectures is illustrated through simulation for distinct events such as rated power flow, load step-up/down and load side breaker closing. Relevant results are discussed to summarize the advantages and challenges for the proposed power transmission architectures.
A Simplified Four Phase Compositional Simulator for Asphaltene Evaluation
Authors: AlGhanem Fahad A. , Jessen Kristian 
Published: April 2019

Abstract
One of the most promising Enhanced Oil Recovery (EOR) methods is CO2 injection. However, if the oil contains asphaltenes, CO2 injection may cause asphaltene precipitation and introduce production related challenges. Conventional three-phase (gas/oil/water) compositional simulators are unable to predict precipitation of asphaltenes and multiphase compositional simulators are required. The use of detailed multiphase equilibrium calculations is very CPU intensive and commercial simulation packages often employ a hybrid model that may not capture the true physics at play.
Conflicting findings have been reported from experimental and theoretical studies: Some studies show that Asphaltene deposition, due to CO2 injection, takes place near the injection well, while others have reported that asphaltene deposition occurs near the production well. True multiphase equilibrium calculations can be used to demonstrate that both findings are possible and that many factors will affect the deposition behavior. Accordingly, a general statement such as CO2 injection causes more asphaltene precipitation relative to hydrocarbon (HC) gas injection is not always true. This added complexity indicates the need for multiphase compositional simulation to delineate asphaltene deposition behavior and quantity.
In this work, we propose a four-phase compositional simulator (gas/oil/asphaltene/water) to predict the asphaltene precipitation during CO2 and HC gas injection processes. A new hybrid formulation, based on a simple table look-up approach, is introduced to replace detailed multiphase calculations (gas/oil/asphaltene) at a CPU requirement that is comparable to two-phase (gas/oil) equilibrium calculations. A range of simulation models/scenarios are presented to test and validate the new formulation against detailed multiphase compositional simulation, and we demonstrate an excellent agreement between the hybrid model and the full multiphase calculations.
The proposed approach is easy to implement in commercial tools and provides a path to allow for more detailed studies of asphaltene precipitation and related production challenges.
Equipment Health Monitoring and Damage Prediction Using Mechanical Stress Soft Sensing Through Data Analytics
Authors: Williams Ryan Scott 
Published: April 2019

Abstract
Fatigue damage due to structural stress is a common problem for equipment used in offshore drilling such subsea connectors and subsea riser joints. Fatigue damage is characterized by the weakening of a structure or component of the equipment due to cyclic loading. Consistently operating the equipment above the operational parameters can lead to premature failure of the equipment causing unplanned downtime and posing a safety risk to nearby workers. There are several methods currently being used to determine cumulative fatigue damage as a way of assessing the operational life of machines used for drilling. Linear cumulative fatigue damage analysis is one of the most used methods for life prediction of a structure and components of equipment subjected to cyclic loading. The model involves examining the operational stress ranges caused by cyclic loading and comparing them to an established fatigue curve to estimate the total utilization and predict equipment failure. However, the linear damage rule (Miner's rule) has several limitations namely: The damage model often depends on complex, and time consuming, stress analysis depicting exact geometry and operating conditions.Damage can only be assessed subsequently, making it difficult to forecast use and plan scheduled maintenance.
This document presents the development of a mechanical stress soft sensing algorithm for determining real-time cumulative fatigue damage using finite element analysis with response surface methodology. The results in this document show that the new real-time cumulative damage determination approach could effectively help address the limitations of the current models by providing a means of determining real-time cumulative damage with little computational power.
Assessment of Mass Gravity Flow Induced Seafloor Scour Impact on Stability of Mudmat Supported Subsea Structures
Authors: Trandafir Aurelian C. 
Published: April 2019

Abstract
Mass gravity flow phenomena resulting from mobilization of unstable sediments on submarine slopes are well recognized as a major geologic hazard for offshore infrastructure development. Previously published research pertaining to mass gravity flow impact on offshore infrastructure has focused on evaluating the direct impact loads generated by the flowing sediment mass in contact with the analyzed infrastructure component, such as a pipeline or a mudmat. In this study, the mass gravity flow impact on offshore infrastructure is addressed from a different perspective by investigating the potential for mass gravity flow induced seafloor scouring. Finite-element analysis is used to investigate the mobilization of near-seafloor sediments in a deepwater setting under the loads generated by a mass gravity flow event. Analysis results representative for a mass gravity flow in the far-field, near-field, and at the location of a mudmat supported subsea structure are presented and discussed in terms of failure mechanism, near-seafloor sediment deformation pattern and associated impact on stability of the subsea structure, in relation to flow thickness and position of the front of the flow relative to the subsea structure. For the case of a mass gravity flow in contact with the subsea structure, an example of failure envelope providing the ultimate lateral impact load from mass gravity flow required to cause instability of the structure, accounting for the flow induced mobilization of sediments underneath the mudmat, is also presented.
Substantially Improved Wind Power Performance
Authors: Baugh Benton Frederick , Whaley Paul Wayne , Harnett Stephen D. , Hammer Layne N. , Kraeger Zackary A. , Fultz Shannon K. , Lamascus Parker L. 
Published: April 2019

Abstract
The University took the approach of trying to get students interested in engineering as a career by focusing on how we might help America become more energy independent, particularly in their wind prone area. This paper is a report on the resulting actual middle school, high school and college student testing demonstrating that the performance of wind turbines can be increased by a factor of at least 10 by updating and revising "best practices". The results clearly show that wind turbine power is a function of the total blade area rather than the conventional understanding that it is a function of the swept area.
Includes test data and history of testing by university students, testing by students of area high and middle schools, and an explanation of why such a substantial improvement in performance is available at this time. This testing will lead not only to additional future student testing at the same size, and also a new generation of larger scale testing to confirm the results as something closer to a commercial size.
Safety Capability of an All-Electric Production System
Authors: Mahler Carsten , Glaser Markus , Schoch Simon , Marx Stefan , Schluenss Stefan , Winter Tobias , Popp Julian , Imle Sebastian 
Published: April 2019

Abstract
The all-electric control system, as proposed with this paper, provides improved HSE, reduced costs, and increases safety and reliability compared to an electrohydraulic system. This paper describes the approach for the development of a novel all-electric safety actuation system. Key to this concept is the centralized battery, which is utilized to provide the system with the required amount of energy during valve actuation for normal operation and in case of a power cut or communication loss. Since instantaneous power for valve operation is supplied by the battery, continuous power demand remains at a similar level for current electrohydraulic solutions.
This paper includes a detailed analysis to evaluate the safety and reliability capability of the proposed all-electric system. It also covers root causes for failure modes and suitable mitigations to prevent occurrence or for failure impact reduction. Further objective is the analysis of common cause failures, which are critical for safety function execution. The paper is a result of the work of a joint industry project.
Wear and Its Effect on Electrical Submersible Pump ESP Performance Degradation by Sandy Flow: Experiments and Modeling
Authors: Zhu Haiwen , Zhu Jianjun , Zhou Zulin , Rutter Risa , Zhang Hong-Quan 
Published: April 2019

AbstractMulti-stage electrical submersible pump (ESP) is a frequently used artificial lift method, especially in high production wells. Severe wear and leakage can be caused by sand production from unconsolidated sandstone and proppant backflow. The loss of boosting ability and system stability under sandy flow condition is hard to be predicted, which not only reduces the production but also causes severe failures. In this study, a closed testing flow loop with a mixed type ESP is constructed to test pump performance and efficiency under water-sand flow. 64 hours total testing time is divided into several short intervals. After each interval test, the deteriorated head and efficiency of ESP with pure water were tested. More head loss was observed under low flow rate region, which is presumably caused by leakage through the secondary flow region. Head curve acquired in the test is compared to other studies to analyze the leakage effect in different regions. A leakage flow map including three different regions is provided. The seals’ ID/OD and clearances were measured after the pump was disassembled. The leakage effect in previous mechanistic ESP performance prediction model is modified based on test results. By using the appropriate geometries, the deteriorated head curve can be calculated. Compared to the test curves, the proposed model agrees well with the head degradation trend. The model can be further improved by adding abrasion and efficiency models with more available data.
Streamlined Natural Gas Treatment by Membranes Only
Authors: Dengel Udo , Karode Sandeep , Ding Yong 
Published: April 2019

Offshore gas treatment faces constraints for space and weight limits. This paper will present an innovative concept of using only membranesto remove multiple contaminants, reduce weight, space and cost on offshore installations and becoming an enabler for gas monetization.
Membrane separation is a cost effective way to remove CO2 from natural gas. The typical offshore membrane treatment package usually consists of a relatively complex pre-treatment step followed by a simple membrane system to remove CO2.
The solution using only membranes for gas treatment consists of:
a first stage of poly (ether ether ketone) or PEEK membranes, resistant to the main impurities in natural gas, able to remove H2S, heavy hydrocarbons and water, thus essentially replacing the pre-treatment for offshore CO2 removal membrane packages
a second stage of poly-imide membranes with high CO2 / CH4 selectivity for CO2 removal
The membrane-only solution can be applied for treatment of large volumes of gas for pipeline specification to remove CO2 and other contaminants. Key benefits are simplicity of operation, compactness of footprint, weight reduction and a reduction in or elimination of adsorbent media replacements. Topside weight and cost reduction can increase gas treatment capacity and flexibility and are an enabler for gas monetization.
Due to their resistance to impurities PEEK membranes can also be used to treat flared gas for valorization through gas-to-power applications, thus reducing flaring. For gas-to-power applications, the gas will undergo some basic conditioning (such as hydrocarbons dew point, BTU adjustment, H2S removal) by a compact membrane unit to be used for power generation on the offshore platform.
Operational Excellence and Product Reliability Enhancement Through Big Data Analytics
Authors: Mulunjkar Amol M. , Deshpande Ashish P. , Steinke Stephen , Chartier Benjamin , Kuwertz Luke A. 
Published: April 2019

Abstract
Schlumberger, one of the world’s leading suppliers of oilfield technology, is a measurement and data-driven company that collects massive amounts of data in the course of its daily operations. These data, diverse in nature, are collected for use in various business and technical workflows. The data can be downhole, surface, post-analysis, and support functions from manufacturing, maintenance, asset management, and finance. Analysis of this Big Data has the potential to drive a step change in operational performance across multiple dimensions. However, accomplishing this step change is not easy to accomplish because often, the data are not well structured and are scattered across individual business systems that do not communicate well with each other. Most of the analysis of these scattered data occurs on a point basis, requiring the significant involvement of various experts and complex time-consuming manipulations. The results are short lived in that they cannot be tracked in real time and the effort expended is not applicable to other data sets or problems. Increasing data volumes, data diversity, and demand from engineers to record multiple new data attributes during the product or technology life cycle further limits the benefits of such a spot analytics process, with potentially severe impacts on the business due to inadequate decision support or missed opportunities.
This paper presents a developmental model and change processes, challenges faced and resolution approaches leading to digital transformation, and finally, the resulting value creation through building data visualizations and comprehensible decision-making tools.
Once the initial high-value data sets and visualizations are identified, automation opportunities can be exploited. These data sets become the foundation for predictive analysis and machine learning through artificial intelligence (AI) and Internet of things (IoT) to further influence product performance and development in support of customer needs.
Pore Pressure Prediction Before and During Drilling Applying the Four Zones Method
Authors: Shaker Selim S. 
Published: April 2019

Abstract
This method integrates the geological building blocks of sedimentation, dehydration to lithification and the formation water hydrodynamic forces associated with each of these phases. The current known conventional velocity – pore pressure transformation models are lacking this relationship.
In the current widely used conventional methods, it is controversial to consider the shallow section as normally pressured and at the same time extract a compaction trend from its petrophysical properties. Moreover, there is confusion about which part of the subsurface section the Effective Stress theorem should be applied to. The novelty of dividing the subsurface into four zones using this new approach reduces the risk of predicting the pore pressure before drilling and the uncertainty of its correct calibration during drilling.
This new pore pressure calculation is done separately in each zone based on the predominant formation-water dynamic. Normal hydrostatic pressure is only assigned to the loosely compacted very shallow section (A). Hydrodynamic zone B with upward formation water flow is associated with compaction and reduction of porosity due to sediments load. Petrophysical trends such as velocity, density, resistivity follows a compaction trend in this zone. As result of depositing shale seal in zone C, due to high stand sea level, fluid is prevented from permeating upward. This low permeable top seal is referred to as top of geopressure (TOG). The geopressured section of zone D below the pressure ramp in zone C follows a cascade outline where the pressure in permeable beds show linear trends and shale exhibits an exponential trend.
The petrophysical properties of the deeper shale beds below the top seal represent several passive compaction trends. Pore pressure prediction in the deep geopressured section D is derived from calculating at the same depth the disparity between the extrapolated velocity compaction trend (CT) values and the measured ones. A unique mathematical calculation is introduced here to establish the compaction trend (CT) instead of the manual graphically extrapolated so called NCT. Before drilling seismic velocity, semblance is a key for defining the four zones. Velocity – pore-pressure transformation modeling is an important aspect of the drilling cost for a proposed location. Moreover, LWD’s during drilling and conventional logs post drilling are the fine-tuning tools of calibrating the pre-drilling seismic-pressure model. The calibrated model is the backbone of any predicted pore pressure in future drilling locations in the same basin.
The pore pressure prediction applying this method facilitates assigning the casing setting and mud programs at the appropriate depths before drilling. Furthermore, it reduces the non-productive time (NPT) and challenges by assessing the subsurface formation pressure including the shallow water flow (SWF), risk of kicks and loss of circulation along the proposed bore-hole trajectory before moving rig on location.
Monitoring Stored CO2 to Document Permanence
Authors: Hovorka Susan Davis 
Published: April 2019

Injection of CO2 into porous rocks deep in the subsurface intrinsically has a low risk of leakage for three reasons: (1) Although CO2 is buoyant compared to brine, layered rocks limit vertical migration. Injection zones are chosen with at least one well-qualified confining system that should isolate CO2 within the selected interval. (2) Capillary trapping of CO2 in the pore system, dissolution of CO2 into formation fluids, and sorption and reaction of CO2 with organics and minerals will further attenuate CO2 lateral or vertical migration. (3) Wells are designed to isolate fluids in the deep subsurface from the overlying water and other resources; even a poorly constructed well will greatly retard migration of stored CO2.
To add certainty to the planned storage, a monitoring program can be designed to document that the plume is migrating as predicted (and therefore that the planned-storage permanence is likely) and to assess any remaining uncertainties, for example, to further reduce well leakage or off-site migration risk.
In an offshore setting, time-lapse seismic is the most preferred tool. A survey collected prior to injection provides the baseline survey. Injected CO2 displaces water and also increases pressure. During repeat surveys, the resulting changes in seismic velocity are measurable. Subtracting the repeat surveys from the pre-injection survey provides a high-quality image of the areas where CO2 has migrated.
Other tools of high value are downhole-pressure measurements and wireline logs used to assess the zones at which CO2 is leaving the injection well(s). Gravity surveys are also used to assess the change in fluid density as CO2 is emplaced, and seismic sensors may be of value to assess microseismic response to injection. An available suite of environmental tools can be deployed to determine if any unexpected change occurs in the overburden, sediment, and water column. Advanced deployments such as fiberoptic cables and remotely operated sensor packages may have high value.
Complexities of and limitations to monitoring must be critically assessed. The material impact of loss of CO2 from storage is forward modeled to determine if tools and techniques selected are sensitive to the changes. For example, if natural gas charge is present in the subsurface, seismic change from injection of CO2 is likely to be small and may be less than noise. Only by rigorous documentation that leakage is detectable can the expected outcome, high-quality storage, be documented. New work is being undertaken to develop optimized and commercializable monitoring for storage projects in the Gulf of Mexico.
This work is related to a new multiyear project assessing the suitability of nearshore Gulf of Mexico for CO2 storage.