bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated Optimization of the Overall Gas Mass Balance in a Deep-Water Production System
Authors: Brioschi Samuele , Cadei Luca , Del Monaco Luca , Raffone Marco , Montini Marco , Bianco Amalia 
Published: November 2018

Abstract
The current oil and gas market context is characterised by low prices, high uncertainties and a subsequent reduction in new investments. This leads to an ever-increasing attention towards more efficient exploitation of resources. This scenario underlines the need for existing assets production optimization, especially for deep-water applications. This paper presents the methodology of an innovative integrated production optimization tool and presents the results obtained in a real application on a deep-water asset.
The optimization tool aggregates in a single integrated platform all the different aspects of the asset, from well performances to topside process simulation through gathering system thermo-hydraulic calculations. It effortlessly orchestrates several pieces of software that model the different parts of the asset. Those are typically used by different disciplines, such as reservoir, well area, flow assurance, process and operations. Therefore, the tool promotes the essential collaborations between disciplines. The production optimization is based on genetic algorithms and is able to increase the production of an asset respecting all the operative and flow-assurance constraints.
The optimization was applied on a deep-water field, posing particular attention on the delicate ecosystem that is the gas lifecycle of an FPSO. In this case, a global and holistic approach is of paramount importance: in fact, the gas associated to the oil production plays a role in the hydraulics of the pipelines and after being dehydrated and compressed, is used as fuel gas, as gas for wells artificial lifting and for re-injection into the reservoir. The application resulted in a global optimisation of the gas utilization and had manifold impacts. Firstly, it resulted in an increase in oil production. Secondly, a reduction in the overall gas lift led to a more energy efficient use of the compressors. Finally, a higher use of the gas for re-injection resulted more effective for pressure maintenance. As a consequence of the theoretical study, the optimization actions identified by the tool lead to a successful application in the field.
This paper presents a novel approach to overall asset optimization that integrates different engineering disciplines. The approach accounts for the overall gas balance of an FPSO from bottom hole to separation, lifting and re-injection.
Use of Exogenous Bacteria to Improve the Bioremediation Process in the Caracara Field Colombia
Authors: Molano Jaime 
Published: November 2018

Abstract
CEPSA Colombia developed an improved technique for bioremediation; implemented since 2012 in the onshore Caracara field. This optimizes the processes of biostimulation and bioaugmentation by introducing exogenous bacteria, with efficiency (reduction of grease and oil) close to 90%.
The technique exceeds the performance of other published methods, as it has been used successfully for the biotreatment of soils and fluids impregnated with hydrocarbons at concentrations of fats and oil of up to 20 ± 2 wt%, equivalent to 200,000 ± 20,000 ppm (mg carbon/kg soil). Previous studies have suggested that oily sludges only with concentrations of fats and oils below approximately half that level can be bioremediated to achieve a compliance criterion standard close to 1 wt% as established in Chapter III of Louisiana Protocol 29-B and commonly adopted as an oil industry norm.
It is an ‘ex situ’ process since although applied at the field location the sludge is first collected and stored prior to batch biotreatment. The technique is most applicable to oily sludges that do not have an excessive asphaltene and resins content: asphaltenes are not biodegradable by microorganisms, given their structural complexity and resistance to the enzymatic attack produced by bacteria.
Our successful field pilot has been expanded to an industrial scale and has over a six-year period effectively treated the environmental liability of sludge ponds of approximately 12,000 m3 inherited when CEPSA assumed its interest in the Caracara field. Operations continue, treating ongoing generation of oily waste at an estimated cost saving of 54% relative to the treatment and transport costs of contracting an external bioremediation service provider.
We have developed simple criteria to screen the suitability of oily sludges for our process, which is simple, easy to implement and cost-effective, as it relies on bacteria generated from waste products readily available in the field at no cost. It should be applicable to other fields with similar environmental conditions.
Combined use of Optical-fiber DAS and a Permanent Seismic Source for Vertical Seismic Profiling Demonstrated at the Aquistore CO2 Storage Site
Authors: Nakatsukasa Masashi , Ban Hideaki , Kato Ayato , Shimoda Naoyuki , White Donald , Nickel Erik , Daley Thomas 
Published: November 2018

Abstract
Seimic reservoir monitoring is a method to monitor fluid displacement in the reservoir. Long-term monitoring to measure differences over several years has been successful recently. However, short-term monitoring to measure changes in nearly real-time is still challenging because the expected changes in such a short-term are small. Permanent reservoir monitoring might enable short-term monitoring because we can increase data repeatability since sources and receivers are permanently fixed at the same position. This method saves the acquisition cost once the equipment is deployed, but the number of sources and receivers is limited due to the high initial install cost. To address this challenge, we have demonstrated VSP monitoring with a combination of a permanent rotary source and DAS sensor. DAS can record a wavefield at very dense and extensive points along an optical fiber, but the quality is regarded as less than for conventional geophones. By comparing data recorded in 2015 and 2016, we investigated the improvement of the signal-to-noise ratio of DAS. Hourly repeatability was checked by arranging the waveforms by the acquisition time. The depth migrated image of the offset VSP extended the imaging are further away from the receiver well. Our study confirmed the complementary relationship between the permanent source and DAS acquisition. Combining these technologies might enable us to monitor small changes in the reservoir in the short-term.
Stress Testing with Improved Wireline Formation Tester in Low Permeability Unconventional Formation
Authors: Povstyanova Magdalena , Coscia Marco , Van Laer Pierre , Makarychev Gennady , Al Marzooqi Hassan , Leyrer Karl , Casson Neil , Cig Koksal , Desroches Jean 
Published: November 2018

Abstract
In preparation for the hydraulic fracturing campaign, the Unconventional Resources Team at Abu Dhabi National Oil Company (ADNOC) has carried out stress measurements both in open-hole and cased-hole in a number of recently drilled wells. The current paper demonstrates the results of the stress measurements in open-hole in two wells drilled in two different geological settings. The main target chosen was the unconventional Shilaif formation. One well was located on top of an anticline and the other well penetrated the Shilaif formation in a syncline. High breakdown pressures were expected (especially in the syncline).
In order to cope with the challenges expected during the stress testing in such environment, a wireline formation tester that included both single packer and dual packer was used to initiate breakdown and achieve measurement of fracture closure pressure. With the expected adverse rock properties, either natural fall-off or rebound technique was employed to obtain closure pressure. The single-packer module extended the differential pressure rating up to 12,000 psia in comparison to 4,500-psia rated dual packer. The single packer was used to initiate the fracture breakdown if dual packer was not considered sufficient. Formation pressures were measured at several depths with the dual-packer operations. The stress measurements were carried out not only in the Shilaif formation, but in the shale formations above (the Tuwayil formation) and below (the Mauddud formation) in order to check if the shales could be stress barriers for a large scale hydraulic fracture.
The current paper explains the procedure followed during the stress measurements and shows an example of interpretation of the pressure data acquired with wireline formation tester comprising the single-packer and dual-packer systems. The stress measurements were used to calibrate results of the geomechanical modeling.
Building a Robust Reservoir Model through Full Integration Workflow of Static and Dynamic: A Case Study from a Lower Cretaceous Carbonate Reservoir of a Giant Oil Field, Onshore Abu Dhabi, UAE
Authors: Pamungkas Setiyo , Flavien Maire , Baptiste Salley 
Published: November 2018

Abstract
An updated geological and dynamic model for a giant Middle East carbonate reservoir was constructed and history matched with the objective of creating an alternative model which is capable of replicating the reservoir production mechanisms and improving predictability, allowing optimizing the field development plan and water injection strategy. Giant Middle East carbonate fields often have long production history and exhibit high reservoir heterogeneity. It is always challenging to get a robust history matched model aligned with geological concepts and dynamic behavior understanding.
The objective of this paper is to present an improved and integrated reservoir characterization, modeling and history matching procedure for a giant Lower Cretaceous carbonate reservoir in the Middle East. The applied workflow integrates all available geological data (stratigraphy, depositional facies, and diagenesis), petrophysical data (RCA and minipermeameter data, Petrophysical Group definition, cut-off definition) and the extensive database of dynamic data (long production history, well test, RST, open-hole log saturation over more than 40 years of development drilling, and MICP). The process was initiated with the reservoir review by means of a fully integrated study that allowed having better understanding of the reservoir behavior and production mechanisms. The key heterogeneities (high permeability and intra-dense layers) which control the flow behavior were identified during this process. Geological trend maps were generated to control the distribution of high permeability and intra-dense in the model. Well test data, open-hole logs from development wells and time-lapse saturation logs from observation wells were used to calibrate the trend and permeability log data. A phenomenological model was constructed to test the main factors impacting the production mechanism as identified during the reservoir review. Multiple iterations were performed between the static and dynamic models in a way that allowed a quick and efficient work that is consistent with all disciplines assumptions.
Such continuous loop between the dynamic and geological models, with focus on the geological heterogeneities driving the dynamic reservoir behavior, has led to a more robust model capable of replicate the production mechanisms, which represents a major improvement compared to previous model in term of predictability.
New Technology to Assist Drilling to Improve Drilling Rate in Unconventional Gas Resources: Pulsed Arc Plasma Shockwave Technology
Authors: Cai Zhixiang , Zhang Hui , Li Jun , Zheng Jiadong , Yu Qing , Liu Kerou , Liu Yongsheng 
Published: November 2018

Abstract
The rate of penetration is very low during the development of unconventional gas resources such as tight gas and marine shale gas, owing to high rock hardness and strength as well as heterogeneities at all scales. To improve the efficiency and reduce costs of developing unconventional gas resources, this paper proposed a new technology to assist drilling, Pulsed Arc Plasma Shockwave Technology (PAPST).
This technology converts electrical energy into mechanical energy to generate dynamic loads shockwave which can assist rock-breaking. Firstly, based on the fluid mechanics and bubble dynamics, the mechanism of shockwave generation was analyzed. Then, to verify the feasibility of PAPST technology, this paper conducted rock breaking experiment with shale samples from Longmaxi formation, China. Meanwhile, based on impact and damage mechanics, the mechanism of rock damage caused by dynamic load was analyzed.
The results show that shale samples were destroyed and there were cracks and collapse pits on shale samples after the impact of shockwave. Therefore, the application of PAPST technology to assist drilling is feasible, and the greater the discharge energy, the higher the efficiency of rock failure. Through theoretical analysis, it is found that the radial cracks of rock are caused by the tangential tensile stress, which is caused by the shockwave impacting the rock. The secant cracks are caused by the resultant force of the three component forces: the tangential and radial components of the force on the rock particle caused by the shockwave and the radial tensile force generated by the reflection of stress wave at the rock-water interface. The collapse pits are most likely caused by stress concentration.
For the first time, this paper proposed an idea of applying shockwave generated by PAPST to assist drilling for increasing the ROP in unconventional gas resources. And it also provided a theoretical basis for the application of PAPST in the field of oil drilling by analyzing the mechanism of shockwave generation in drilling fluids and the mechanism of rock breaking by shockwave.
Using Similarity-Based Pattern Detection to Automate Pressure Transient Analysis
Authors: Suzuki Satomi 
Published: November 2018

Abstract
Automated pressure transient analysis (PTA) with real-time data feed from permanent downhole gauge (PDHG) enables continuous monitoring of well and reservoir that facilitates timely surveillance decisions. However, while robust automation of the process is critical to minimize the requirement of manual efforts, a challenge lies in automatic diagnostics of a log-log plot which is often contaminated by non-reservoir response such as wellbore dynamics. We propose a new automatic PTA method to enhance accuracy of diagnostics.
The method utilizes a pattern detection method based on similarity search and automatically identifies sequence of flow regimes, such as radial, spherical or linear flow etc., on a log-log diagnostic plot of pressure and derivative. To discover individual flow regimes, the algorithm scans a window on the plot and finds a pattern that is most similar to a ‘motif’ defined for the flow regime. Such motifs are known for individual flow regimes from analytical models. During the similarity search, the algorithm ensures that the discovered sequence of flow regimes is consistent with the flow scenario anticipated at the well.
The proposed method is implemented in fully automated PTA workflow. First, the system reads PDHG pressure and flow rate at a well. Then, pressure buildup intervals are automatically identified. Subsequently, a log-log diagnostic plot is automatically generated for each buildup and the proposed method is executed. Once a sequence of flow regimes is identified, the algorithm locates a horizontal line over the radial flow regime and calculates permeability, skin and extrapolated pressure p*. For horizontal wells, effective completion length is also computed by locating a half slope line on the linear flow regime. For hydraulically fractured wells, fracture length or fracture conductivity is estimated from the linear or bi-linear flow regime. The results are written on output files or to a database together with identified flow regimes visualized on plots for the review of reservoir engineers. The method is tested on oil producers with high water cut where significant fluid segregation or crossflow is impacting log-log diagnostic plots, as well as gas wells where a pressure leak during buildup is contaminating pressure derivatives. Despite such noise of non-reservoir responses, the proposed method successfully identifies flow regimes on most of buildups and produces PTA results comparable to manual analysis.
Compared to existing automatic PTA methods, such as automatic matching of model response or automatic semi-log analysis of radial flow regimes identified by user-specified criteria, the proposed method is particularly robust to use with pressure data which is significantly contaminated by non-reservoir responses. Such robustness of our method is achieved by a flexible pattern search for individual flow regimes rather than matching an entire model response all together or requiring rules specified by engineers.
Real-Time Slickline Production Logging: Technology Review
Authors: Alghamdi Abdullah , Yateem Rakan , Rajeh Rashed , Kadem Mohammad 
Published: November 2018

Abstract
Out of the many well intervention jobs conducted, the focus of discussion of this paper includes two well intervention operations using digital enabled slickline services in combination with production logging operations in fields whereby bi-directional telemetry is enabled using a proprietary plastic polymer insulating coating around a conventional slickline wire.
The smaller, lighter and easier slickline conveyance platform with its simplified stuffing box pressure control equipment enables direct and subsequent efficiency gains and risk reduction in providing both enhanced mechanical slickline services and an additional range of real-time downhole measurements. This combination enabled both services to be deployed in a single rigup with one digital enabled slickline unit used for both mechanical and measurement services on each well. This can reduce operational time and provide significant cost savings and a reduction in diverted and or delayed production. As an example, the real-time head tension readout was used to monitor the downhole tool movement and lift forces during the flowing survey allowing the well to be flowed at the optimal rate.
Two risk mitigation devices were incorporated in the toolstring, a real-time activated release device, and an interactive jar allowing mitigation of the associated risks should the toolstring become stuck in the well. The case studies described in this paper demonstrate the ability to provide a range of intervention services, specifically in the vertical logging operations, with the real-time surface readout measurement and control usually associated with electric line operations.
The surface readout capability and depth accuracy makes this system more a better fit than a conventional memory system, and due to the variety of sensors available it is comparable with an electric line production logging operation. Although the technology is for cased hole service, real-time data was also acquired in the openhole section. The operations conducted as described in this paper show that digital enabled slickline services are well on their way to becoming a proven service in enhancing operational efficiency and delivering a new level of complexity to real-time slickline deployed measurement services and control over the entire operation
Offshore Optimizations: EICT Systems, Installation and Footprint
Authors: Hage Safouan 
Published: November 2018

Abstract
The objectives of this paper are to highlight and discuss the role that Electrical, Instrumentation, Control and Telecom Systems (EICT Systems) can play in an optimization drive for offshore installation, let be on the footprint aspects, installation methodologies, mechanical completion and overall commissioning to first oil.
The Methodology being presented is based on converging the EICT Systems into an integrated approach in a homogenous EcoSystem building on the strength of the Systems Interfaces. This will cover the full lifecycle of those Systems from Engineering to Assembly and integration up to installation, testing and commissioning. The standard approach had been with these systems being addressed separately, while many of the design and implementation data and parameters converge into common interfaces that affects the overall aspect of Offshore installation like Ehouse Structures, back-up power supply systems and common Electrical, Process and Safety Control Interfaces and Platforms as examples.
We have been able to deliver a more optimized and efficient engineering with reference architectures, able to absorb variations without major impacts on delivery and commissioning schedule. Accordingly, we have better Systems Build-ups with optimized Interfaces and lesser footprints in Space and Energy consumption, i.e. Ehouse Structures (LERs and ITRs), Back-up Power Systems and Outdoor Equipment. Also, this has resulted in a more efficient installation and commissioning, i.e. less cabling and marshaling. This has led to a better offshore space allocation and Management, improved schedules for engineering, installation testing and commissioning and ultimately resulting in a better Cost of ownership at CAPEX and OPEX
This paper will discuss some of the critical interfaces mentioned above, like Ehouse and Integrated Process and Power Management and how the EICT Integrated approach will help deliver these Systems in an optimized and efficient manner to deliver the stated results and conclusion
Feasibility Study of Carbon Dioxide Methanation: Assessment of Various Supported Nickel Catalyst
Authors: Berahim Nor Hafizah , Abu Seman Akbar , Mohd Noh Mohammad Ghaddaffi 
Published: November 2018

Abstract
Carbon dioxide (CO2) management is vital for ensuring the economic and environment viability for monetization of high CO2 gas field. Apart from the great technical challenge in separating high concentration of CO2 in gas field economically, the management of separated CO2 is a fine balance between the sink-in value by sequestration and creation of value via conversion to product, constrained by the thermodynamic challenge in breaking the stable CO2 molecule. Conversion to methane is one the exploratory idea due to ease of integration to current product line-up of PETRONAS. Catalytic conversion of CO2 to methane are reported here over various supported nickel base catalyst, namely ZrO2, La2O3, and Al2O3 at temperature ranging from 300 to 400°C under atmospheric pressure. The catalysts with fixed Ni loadings were prepared by wet impregnation technique, characterized and their performances were evaluated in a parallel reactor under Sabatier-based CO2 conversion. Reaction temperature and GHSV were taken into account as two important parameters with fixed H2/CO2 molar ratio. Experimental results indicate that among all catalysts, Ni/Al2O3 give the highest CO2 conversion of 74% and high CH4 selectivity of 99% at temperature of 380°C and GHSV 10000 h-1. This asserted Ni supported on Al2O3 as a potential catalyst for CO2 conversion and promising methanation performance over a low cost catalyst.
Minimize Measurement Uncertainties to Gain More
Authors: Valasubramanian A 
Published: November 2018

Abstract
In today's competitive world, trillions of BTU's of energy through sales gas are traded every day. Natural gas values were considered not that high compared to that of Crude oil in the past, with the drive to use environmentally clean energy source more sales gas is being used now. This provided the opportunity to improve the gas custody measurement accuracy further. This paper discusses the gas flow measurement all the compnents contributed to the accuracy and the ways to minimize the measurement uncertainty.
Gas Custody Measurements are special applications, and different from the normal process measurements. Gas Custody measurement standard volume, mass flow and /or energy readings are not direct measurement value, rather it is a calculated output. It is a computed value based on several measurement data points with some underlying assumptions.
Typical sales gas metering systems with redundant meters for proving / standby is provided and the typical configuration is indicated in the Fig-1 below.