bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Study: Impact of Risk Mitigation Systems and Solutions on the Fluid Sampling Success Rate and E&P Project Economics of a Large North Sea Field Development Project
Authors: Castillo Homero , Scott Graham , Wills Phil 
Published: March 2015

Abstract
This paper documents the outcome of an eight-year field study that confirmed how the consistent use of innovative conveyance methods and technologies significantly improved the success rate of fluid sampling programs while reducing the overall cost of the E&P projects in long-reach challenging wells part of the largest development project undertaken in the last 25 years in the UK, North Sea sector.
The formation properties encountered by these wells along their trajectories, including long deviated sections, posed massive challenges to the acquisition of critical formation evaluation (FE) data, core samples and representative formation fluid-samples required in these wells.
In the early stages of this field development, the most significant risks encountered were differential sticking of the wireline-conveyed sampling tools and differential sticking of the wireline in very permeable reservoir rocks. The direct consequence of a stuck sampling tool is the need to fish the sampling tool first and then recover the required fluid samples using pipe-assisted wireline conveyance methods, a sequence that typically takes five additional days. The additional cost to the Project Partners is $4.0 million, based on five days rig spread costs plus the deferred production revenue losses resulting from the five-day production delay of all development wells not yet drilled/completed from the same installation.
During the first eight fluid sampling operations in the development phase of this field the fishing rate was as high as 25%. The development and adoption of modern methods and technologies to manage the conveyance risks identified when performing coaxial packer sampling in 2012 resulted in no wireline fishing jobs (0% fishing rate) and no pipe conveyed logging (PCL) operations required (0% PCL rate) on these UK North Sea projects.
The structure of this paper follows:Overview of the oil fields and the development programs subject of this paperCharacterization of the conveyance hazards present in the wells where the wireline logging jobs subject of these paper were executedDetailed description of each of the key wireline risk-reduction technologies used through the duration of these field developments and the roles they played on the success of the wireline logging jobsConclusions and recommendations for similar field developments on wireline risk mitigation
The Systematic Closing of the Performance Gap in Hydraulic Fracturing
Authors: Bychina Maria , Guk Vyacheslav , Wolcott Don , Economides Michael J. 
Published: March 2015

Abstract
Hydraulic fracturing is the overwhelming completion method in the international petroleum industry. It is estimated, that today it has become a $20 billion industry. It is also one of the most challenging enterprises, incorporating scientific information from geology, reservoir and production engineering, rock mechanics, complex fluid rheology and field economics.
More than a decade ago we introduced the concept of Unified Fracture Design (UFD) as a means towards physical optimization. Since then UFD has been adopted by a great number of practitioners and hundreds of papers have been published. Not all approaches have been successful, nor have they been done appropriately. In this work we relook at the whole issue in a systematic way.
We have identified and describe here a 9-step sequence to mitigate the gaps and help in the optimized field application of modern hydraulic fracturing. These include:Required minimum reservoir characterization: Typical log description.Estimate of k, h, interlayer stress contrast, distance from water.Optimization of fracture size using UFD. Maximum dimensionless PI at optimum conductivity. Optimization of drainage shape and stimulated reservoir volume (SRV).Unique monitoring execution, other than the traditional net pressure or injection variables. New benchmark indicators are used, cross-plotting descriptive variables such as: level of pressure vs. volume of fluid injected vs. operational characteristics, such as tip screen-out.4. Fracture injection tests, designed for fluid efficiency, closure pressure, leak-off coefficient and the newly developed capability for after-closure analysis for well and reservoir variables.For multifrac applications such as shale gas, horizontal wells in very low-permeability formations, zonal isolation and perforation strategies are essential issues.Design of injection schedule to accomplish the desired fracture geometry is the next concern. What happens if things go wrong? The strategy of contingencies must be in place before the execution starts.On-the-fly redesign responding to contingencies, such as net pressure constraints and formation barriers. Ability for alternative plans quickly.Once the job is completed the next step is whatever is necessary to close the fracture and flow the well back. What needs to be done in different geologic settings?Finally, to close the circle, performance evaluation is indicated, which involves comparison between actual performance and expectations and the definitive reconciliation of any discrepancies.
Modeling Bitumen Presence and Its Impact on Reservoir Performance in the Arab D Reservoir, Dukhan Field, Qatar
Authors: Hasiuk Franek , McKinney Andy , Meek Fred , Dwiyarkoro Broto , Jamieson Hank , Al-Ansi Hussain , Miller James K. 
Published: March 2015

Abstract
A recent integrated geologic modeling and reservoir simulation history-matching effort in the Arab D Reservoir, Dukhan Field, Qatar, has found that the presence of bitumen and the extent to which it saturates porosity and impairs permeability are the key factors in matching water production history in wells located near the oil-water contact (OWC). By using production data, the ability to predict the location and continuity of permeability-reducing bitumen was greatly increased.
In this study, many past attempts at visual and petrophysical identification of Dukhan Arab D bitumen were quantitatively compared, and visual macroscopic core descriptions were found to be the most accurate. By integrating core and petrophysical data with the structural history and the timing of hydrocarbon migration and bitumen generation, a predictive model was constructed to identify the part of the reservoir most likely to contain bitumen, the "bitumen prone interval" (BPI). Within this interval, the presence of bitumen was determined stochastically away from well control using facies modeling techniques. In each bituminous cell, bitumen saturation was calculated through statistical analysis of core plug porosity data from inside and outside the BPI. The resulting reservoir model provided both a conceptual match to the working knowledge of bitumen distribution at Dukhan and a directional match to the overall field production history. However, this approach was unable to match individual well performance or the variability in areal sector behavior with a high degree of accuracy.
While direct observation of bitumen is limited to cored wells, producing wells above the BPI provide indirect evidence of bitumen presence for model calibration. Through iteration with the dynamic reservoir simulation model, bitumen distribution, saturation, and permeability were modified systematically within the predicted BPI to better match the behavior of both individual wells and areal sectors of the field.

Introduction
Bitumen is an aspect of reservoir quality that can have significant impact on fluid flow in a reservoir. However, characterizing bitumen distribution and saturation is a non-trivial task due to its petrographic, petrophysical, and geochemical complexity. While the appropriate modeling of reservoir bitumen is challenging, it is not outside the abilities of modern petroleum geoscience. Bitumen was a key parameter chosen for inclusion in constructing a new three-dimensional geological model for Dukhan Field because of its potential for improving the history match.
A Study of Acoustic Wave Propagation inside Cemented Production Tubings
Authors: Farraj Abdallah K. , Miller Scott L. , Qaraqe Khalid A. 
Published: March 2015

Abstract
Well operators use advanced downhole telemetry systems to monitor the flow rate, temperature, and pressure inside the well. The wired telemetry tools are currently popular in the industry although these tools have cost, maintenance, and reliability issues. Acoustic waves that propagate by vibrating the pipe&apos;s body inside the well were recently considered as an alternative technology. However, the bottom segment of the production tubing is encased in concrete in many wells; a previous work showed that concrete segments attenuate the acoustic waves to impractical levels, which limits the applications of this mode of propagation.
As an alternative to vibrating the tubing body when there is a concrete segment over the pipe, this work investigates the use of the production tubing&apos;s interior as a communication medium for the acoustic waves. A testbed was designed using five segments of 7-inch production tubing to form a pipe string, a speaker to generate the acoustic waves, and a directive microphone to receive the acoustic waves propagating inside the pipe string. To study the effect of cemented pipes on acoustical wave propagation, the third pipe segment was encased in concrete. Input frequencies from 100 Hz to 2000 Hz were investigated; wave measurements were taken along the pipe string, and measurements were analyzed to extract information about the behavior of the acoustic channel.
This work shows that acoustic waves are not affected by the presence of the concrete segment. Low-frequency acoustic waves experience very little attenuation as they propagate through the interior of the pipe string, signal dispersion is not an issue for most frequencies, and delay spread measures increase as the acoustic waves propagate down the pipe. This work advises that acoustic-wave technology can be a promising cost-effective and reliable solution for wireless downhole communication systems.
Technical contributions include: characterizing the channel response to different input frequencies along the pipe string, investigating the power spectral density and signal-to-noise ratio measures, and studying the time dispersion parameters of the channel.

1. Introduction
Wireless communications is a discipline that has widespread applications in different industrial areas. The gas and oil industry is one of the recently growing areas for potential applications of wireless communications technologies. Such technologies can be used for addressing issues in exploration, drilling, and production stages. For instance, well performance and production efficiency can be enhanced by having a means to communicate between surface and downhole tools. Readings of typical well data like oil/gas flow rate, pressure, and temperature can be helpful in monitoring the performance of the wells.
Improvements of Sampling and Pressure Measurements with a New Wireline Formation Tester Module in Carbonate Reservoirs
Authors: Cig Koksal , Osunluk Halil Ibrahim , Naial Radwan , Ihab Tarek Mohamed , Al Baloushi Ahmed Yahya 
Published: March 2015

Abstract
A multilayer hydrocarbon reservoir in Abu Dhabi land is in an appraisal stage before experiencing an extensive field production operation. The hydrocarbon reservoir, having medium to low permeabilities, consists of a number of carbonate layers with their associated oil-water contacts. One of the challenges is to sample hydrocarbons in tighter layers as well as to measure valid reservoir pressures to determine oil-water contacts. While the goal is to accomplish the objectives with wireline formation testers (WFT) in openhole conditions, stationary times during logging are limited due to wellbore conditions. The time limit has been a longstanding challenge in the layers having especially lower permeabilities (&lt;1md).
A typical sampling operation involves advanced modules of WFT including a Dual-Packer and an Insitu Fluid Analyzer to identify fluid types and provide downhole compositions with densities. Reservoir pressures are measured generally with Single-Probe modules. The new WFT inlet module is introduced first time in Abu Dhabi across the carbonate formations to accelerate the stationary operations. The new inlet module showed an improvement over a Dual-Packer and a Single-Probe modules in several aspects: Stationary times during sampling are reduced due to very low interval volumes in comparison to a Dual-Packer module and up to 60% faster oil breakthrough times are achieved.Tight zone pressures are measured as fast as a Single-Probe module with lower supercharging effects.Set and retract times are shortened so that a new sampling method of a set-retract-reset is developed without exceeding stationary times.
This paper summarizes the recent achievements by reducing risks associated with long stationary times. The field benefits are demonstrated in two separate WFT operations by comparing data qualities and job efficiencies in the same reservoir layers. Results show faster sampling, more accurate pressure and permeability measurements in the carbonate reservoir.
Application Of Technologies For Improved Drilling, Hydraulic Fracturing, And Production Increase - Case Studies From Deep And High Pressure Gas Wells
Authors: Rahim Zillur , Al-Anazi Hamoud , Al-Kanaan Adnan , El-Mofty Wael 
Published: March 2015

Abstract
Integration of technologies and application of innovative practices in drilling, completion, acid stimulation, and hydraulic fracturing have significantly contributed to the successful development of tight gas reservoirs. The well planning and development procedures entail careful selection of several critical parameters such as drilling azimuth, lateral length, well trajectory, drill-in fluids, well completion methods, stimulation fluid properties, fracture placement technique, proppant types, treatment volumes, and pumping schedule. All of these critical parameters impact fracture dimensions, proppant transport and placement, as well as stimulation efficiency and effective post-frac cleanup.
Depending on reservoir rock properties and stress profile in the near wellbore (NWB) and the far field, the effectiveness of hydraulic stimulation in connecting the wellbore to the undamaged virgin reservoir, as well as maximizing reservoir contact area and enhancing flow back of treatment fluids to restore proppant conductivity, dictate the well potential, sustainable gas rate level, and ultimate recovery. Successful fracture stimulation is therefore measured not only by proper pumping and placement of the designed treatment, but more importantly by the post-treatment stabilized production rate after the well is cleaned up and flowed back.
Crises Management in the Oil and Gas Industry
Authors: Odemene Glory C. 
Published: March 2015

Abstract
Crises are situations that disrupt systems, processes, and lifestyles. They adversely impact individuals, assets, prospects, operations, and reputations of organizations and societies on short and long-terms with significant environmental, social, economic, political, and legal consequences hence the need for priority attention to crises management. This study focused on crises in the oil and gas industry with special emphasis on the lingering situation in the Nigerian-Niger Delta between the communities, the oil and gas companies, and the Government. They became international concerns due to kidnappings, fatalities, assets destruction, environmental degradation, and poverty in the oil-rich region. Despite the industry's substantial expenditure on security, kidnapping and vandalism persist as restive youths who feel marginalized, seek to hurt systems they believe, denied them quality life.
Despite general knowledge and blames traded by parties involved, the study used qualitative-historical-narrative-approach to interview representatives of communities, oil and gas companies, and Government to discover root causes of the crises. Coping theory by Lazarus and Folkman and crisis decision theory by Sweeny were utilized to understand the reasoning and responses of the people to the decisions and management strategies of the Government and oil and gas companies.
Collaboration and Smart Fields - Experience from Global Scale-Up
Authors: van den Berg Frans G. , McCallum Giles A. R. , Graves Matt 
Published: March 2015

Abstract
Shell's Smart Fields programme has built elements of Intelligent Energy into the key field developments over the past ten years. Considerable value has been achieved, from new technologies, new ways of working and global implementation.
In Shell, Collaborative Work Environments (CWEs) have been implemented on a large scale, mostly focusing on the production and field surveillance area and on the real time drilling monitoring. More recently, collaborative work environments have been set up to streamline field development planning. The environments have provided significant benefits to the assets, by enabling new ways of working, improved communication and faster decision making.
Shell and Wipro have teamed up to establish a flexible, global, large scale implementation programme. Gradually, the programme has converged on standard solutions and designs for processes and technologies and on a lean implementation methodology.
Strong focus has been placed on embedding the changes into the organisation. Enticing field teams to adopt and keep new ways of working has required some inventive methods and intensive coaching of staff at all levels.
In this paper, we will show:An overview of Shell's Smart Fields programmeExamples of Collaborative Work Environments in the Middle East and other parts of the worldBenefits obtained from collaboration and Smart Fields solutionsPeople focused activities to embed new ways of workingWays to sustain the solutions and the benefitsLessons learned

Shell's Smart Fields Programme
In the past decade, Shell has developed and implemented Smart Fields technologies, making business cases and implementing the technologies as widely as feasible (see for example Potters and Kapteijn 2005). The uptake of the ‘smart’ technologies and sustained benefits was achieved across the global portfolio of assets in Shell. This has led to broad experience of deployment and sustainability, covering many operating environments, in terms of desert to arctic, field development/depletion types and various organisational models (e.g. Gerrard et al. 2010, Perrons 2010 and Cramer, Mabian and Tulalian 2010).
This has led to major contributions to the bottom line. The value of Smart Fields for Shell and its partners was assessed as 5bln US$ as a result of the smart technologies (Van den Berg et al., 2010). Learning from successes and failures in implementations, has provided deep insights in optimising of the approach for technology deployment.
Entering the second decade, the focus of the Smart Fields programme is on accelerating the implementation of the matured and new technologies across the world wide asset base, on realising the value and on sustaining the solutions and the benefits (De Best and Van den Berg 2012).
Seismic-Based Stochastic Porosity Prediction in a Giant Field: A Fine-Scale Quantitative Approach in Carbonates.
Authors: Samantaray Shubhabrata , Moyen Remi , Michel Jean-Marc , Bouziat Antoine , Yahia Ashraf , Al Zaabi Naema 
Published: March 2015

Abstract
Stochastic inversion of 3-D seismic data is used increasingly for reservoir characterization. It provides information on the reservoir at a much finer scale than deterministic inversion and delivers multiple scenarios for uncertainty analysis. In this work, a stochastic seismic inversion workflow has been developed to characterize porosity variations in the Thamama reservoir of the giant Field, onshore Abu Dhabi.
In contrast to traditional band-limited inversion, this stochastic inversion workflow first generates high frequency models of acoustic impedance which can be used directly for geomodelling without downscaling. Next, a collocated co-kriging sequential Gaussian simulation technique has been applied to generate fine scale 3-D porosity realizations constrained by the impedance stochastic models and by log porosity data.
In the example, post-stack stochastic inversion is combined with stochastic porosity modeling to characterize the uncertainty in the spatial distribution of thin, low porosity / permeability intra-Thamama layers, which adversely affect the field water flood performance. These thin layers have been mapped using seismic-constrained stochastic workflow. P10, P50 and P90 porosity realizations have been generated which represent more or less pessimistic scenarios of lateral extent of the tight zone along the flank of the field. A number of blind wells demonstrate that the seismic-based workflow provides more accurate porosity predictions than a purely well-based reservoir model. Specific technical contributions of the work include:Demonstrate the value of seismic information for characterizing mature carbonate reservoirsImplement field-specific stochastic workflow to characterize uncertainty in spatial extent of thin reservoir flow barriers from 3-D seismic dataPerform seismic inversion directly in fine-scale stratigraphic grid to facilitate integration with the field geomodel
A Review of Alternative Methods to Classify Rock-Types from Capillary Pressure Measurements
Authors: Lalanne Bruno , Rebelle Michel 
Published: March 2015

Abstract
Lab capillary pressure Pc measurements are routinely performed on core plug samples. Applications of Pc curve measurements are mainly to derive some relationships between water saturation Sw and the height H above the Free-Water-Level FWL. The resulting correlations can then be cross-checked vs. the Elogs-derived Sw so as to confirm the overall consistency of the Sw model. Ultimately, the Sw - H relationship can be used as input to the 3D model.
In addition, screening of Pc - Sw relationships often allows defining robust rock-types, based on observation of Pc clusters vs. the sample porosity, permeability, mineralogy and geological facies. In the case of MICP, the rock-type classification may be further enhanced by looking at the Pore-Throat-Radius PTR distributions, related to the derivative of the Pc curve.
Several methods to derive Sw - Pc relationships and classify Pc clusters are possible (e.g. Leverett, Thomeer, Johnson, Cuddy, Skelt, ..) and have been documented and published in the past.
In this paper, we make a synthetic review of the pros and cons associated to each Pc classification method. Eventually, we propose an innovative way to take the best of several known Pc classification methods in defining a straightforward technique to derive robust Pc clusters and equations.