bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple Deployments of Large Diameter Hybrid Drill Bits with Optimized Drilling Systems Prove Enhanced Efficiency in Exploration Wells
Authors: Omar M. G. , Lee R. , Holliday A. , Taha M. , El Touny S. , El Touny S. , Al-Sarraf A. , Abdullah M. , Mahalanobis P.
Published: December 2015

In Kuwait's largest reservoir, the Burgan Field, exploration wells have large potential for drilling optimization and savings; specifically a 22 inch hole, that is drilled conventionally using multiple roller cone bits in multiple trips through challenging inter-bedded formations. Hybrid drill bit technology, roller cone combined with Polycrystalline Diamond Compact, was introduced in search for an economically viable solution to deliver wells faster and achieve yearly operator targets. This paper analyzes the breakthrough drilling performance achieved by a 22 inch hybrid bit in comparison to conventional roller cones offsets and provides conclusions on economic viability.

The main challenges drilling the 22 inch section are drill bit durability and drilling vibrations through inter-bedded formation layers of limestone, shale and sandstone. In addition to curing fluid losses in certain porous formations that negatively affect Rate Of Penetration (ROP). Typically two roller cone bits are used on rotary drive to drill this section at 15 feet per hour, consuming seven drilling days. Using Polycrystalline Diamond Compact (PDC) bit with a performance motor to increase ROP performance is not an economically viable solution. Using hybrid drill bit on rotary drive combines the benefits of PDC blades' durability and higher cutting efficiency with the cones' stability by grinding and gouging into the formation.

The deployment of the hybrid technology was a collaboration project between a national oil company and a major oil services company. The teams focused on optimizing the complete drilling system including the bottom hole assembly, hydraulics, drilling parameters and geological factors to match the hybrid drill bit mechanism.

The hybrid design selection and drilling optimization resulted in a 142-percent ROP improvement from offsets average performance. The hybrid designs consistently drilled the 22 inch hole after casing shoe to section total depth at 31 feet per hour, using one bit, in three drilling days in comparison to seven days average performance. The total operator savings from e section was approximately USD 175,000 in the first deployment. The second and third deployments established performance consistency. Such remarkable economical savings and technical optimization proved that the hybrid technology is the viable solution for two prolific exploration applications.
Integrated Reservoir Delineation in Karst Carbonate: Case Study of Middle Tarim Basin, West China
Authors: Zhang Zhenghong , Tong Yanming , Li Shiyin , Yang Pin , Guan Baozhu , Zhao Chunduan , Lu Guanghui , Hauser Ken
Published: December 2015

The study area covering about 700 square km is located at the west of middle Tarim basin of West China. And the study interval is the top of Yingshan formation of early Ordovician which is a carbonate unconformity, from which the operator just plans to develop much more hydrocarbon than that at previous exploration stage.

The burial depth of study interval is usually around 6000 m deep and the carbonate matrix is too tight to hold any hydrocarbon, so the storage spaces are of dominantly karstic types such as caves, vugs and fractures. But the characteristics of these karstic reservoirs seem to be very different from the ones of fracture-cave systems formed by continental underground streams.

The main aim of this study is to predict and recommend optimized placements of future wells for this possibly different kind of karstic carbonate reservoirs based on multi-disciplinary study results. So the study is really an integrated one, including seismic processing, petrophysical review, combined geophysical and geological (G&G) interpretation and analysis, seismic inversion, geomechanics modeling, reservoir engineering analysis, sweet spot screening and trajectory recommendation.
Optimising Reservoir Management With Improved Time-Lapse Processing on 10 Acquisition Vintages Over the Foinaven-Schiehallion-Loyal Fields
Authors: Campbell S. , Schons M. , Mathew S. , Riley D. , Hill C. , Allan P. , Gubbala E. , Alexe M. , Dervish-Uman C. , Khalil A. , Deschizeaux B. , Hoeber H.
Published: December 2015

The Foinaven-Schiehallion-Loyal area, located west of Shetlands on the UK Continental Shelf, has provided significant oil production for BP (operator) and its partners Shell (Schiehallion/Loyal), Marathon (Foinaven/East Foinaven), OMV (Schiehallion) and Faroe Petroleum (East Foinaven). 4D seismic has been successfully used in this region for infill drilling and reservoir management decision-making since the late 1990s. With a new 4D monitor survey acquired approximately every two years, the total number of vintages now stands at 10. The very earliest monitor surveys were acquired without 4D specification, but all later acquisitions were designed for 4D. The latest monitor survey from 2013 incorporates broadband acquisition technology and can serve as a baseline for future acquisitions.

This paper shows how recent improvements in seismic time-lapse processing enhance the quality of the 4D seismic compared to the previous processing between 2008 and 2011 (Campbell et al., 2011): The 4D background noise is reduced, giving us a better stand-out of the 4D signal. Importantly, legacy data acquired before the advent of dedicated 4D acquisitions can also be significantly improved with new processing methods. A combination of incremental changes to the 4D processing sequence, new 4D algorithms such as 4D demultiple, and careful QC and developments from the continuous technology collaboration gives us increased confidence in the 4D interpretation and satisfies the needs of the reservoir management team.
Cap Rock Restoration in Plug and Abandonment Operations; Possible Utilization of Rock-based Geopolymers for Permanent Zonal Isolation and Well Plugging
Authors: Khalifeh Mahmoud , Hodne Helge , Korsnes Reidar I. , Saasen Arild
Published: December 2015

The fundamental of a plug and abandonment operation is to restore cap rock functionality for securing the well-integrity permanently. The current work reviews briefly essential characteristics of plugging materials. Besides, since geopolymers have been suggested as a possible well barrier element, rheological behavior and mechanical properties of a rock-based geopolymer is presented. The consistency and viscosity of different mix designs were investigated to study the placeability of the mixes. Although the slope of the acquired viscosity data may show a Newtonian fluid behavior, a non-Newtonian model (Herschel-Bulkley) simulated the experiments with a lesser deviation than the power-law model. Strength development of the produced geopolymers showed sufficient strength. Confined triaxial compression tests were performed to measure the Bulk modulus, Poisson's ratio, E-modulus and Young's modulus at downhole conditions. Very low Young's modulus (238 Kpsi) and Poisson's ratio (0.01) were measured. The setting time of the mixtures was delayed by using sucrose without compromising the right-angle-set. The use of sucrose as a retarder by 1.9 w% of the total solid phase did not affect the mechanical properties. SEM analysis showed some unreacted aplite particles within the geopolymers. The initial results showed that the rock-based geopolymer has the potential to be utilized as a well barrier element for permanent well plugging and zonal isolation.
Managing the Upstream-Midstream Integration for FLoating LNG Projects
Authors: van der Velde Harry
Published: December 2015

Objectives

The objectives of this paper are:

To explain that conventional interface management is not sufficient to design an integrated system for a Floating LNG facility To describe methods used by Shell to design upstream and midstream components ensuring that they will jointly work as an integrated system from well bore to off-loading arm To explain FLNG specific issues i.e. differences in FLNG upstream – midstream integration relative to conventional FPSO and onshore LNG design
Study on the Optimal Topological Structure of the Producing Pipeline Network System of CBM Fields
Authors: Haoran Zhang , Yongtu Liang , Mengyu Wu , Chen Qian , Ke Li , YueLong Yan
Published: December 2015

Coalbed methane has attracting much attention as a kind of the new energy source, with ever increasing demand in energy consumption. Pipeline networks of CBM fields are characterized by their complex topological structures and high investment costs. Therefore, the optimization of the pipeline network topology structure will be very helpful in lowering the production costs. The paper discusses four main structures: (1) the well gathering connection, (2) the nearby insertion connection,(3) the valve gathering connection and (4) the combination of well gathering and valve gathering connection. The optimal models which aim at minimizing total investment are solved by genetic algorithm with hybrid encoding by Hash table. The models have taken factors such as flow rate balance at nodes, constraints of the flow velocity, the minimum inlet pressure, maximum operating pressure, maximum number of wells connecting the valve block and the geographic condition into consideration. The paper comes up with a sort of regionally surviving convergence criterion which focuses on models that are strongly discontinuous and prone to be trapped in a local optimum. Taking 46 wells in a CBM field as an example, the paper works out the optimal topological connection for each structure. The result shows that the investment costs, calculated by the regionally surviving convergence criteria, are reduced by a maximum of 11.94% as compared to the traditional one. Also computing time is sharply saved. This study provides a guide line for reducing the cost of producing pipeline networks in CBM fields.
Integrated Workflows for Recognizing Geohazards and Modelling of Karst: A Case Study From the Bul Hanine Field, Qatar
Authors: Al-Jaadi O. S. , Sugiharto A. , Srivastava A. K. , De Almeida Netto S. L. , Bliefnick D. M. , Djebbar Z. , Al-Ali M. A. , Kamal M. A. , Abdo Aly T. M.
Published: December 2015

The presence of shallow gas pockets, karsts and dissolution features in proximity to faults is a common geological phenomenon in carbonate reservoirs. Such subsurface features have been known to have an impact on well planning, assessment of hydrocarbon volume in place, well management and overall development strategy. Therefore, there is a strong business case to identify and map out these features in detail for field development purposes.

The presence of karstification in carbonates causes heterogeneity at various scales. In the Bul Hanine Field, several wells have experienced losses of various degrees. Mud losses at the reported depths have been correlated with the presence of karst-related features. Knowledge of the distribution and geometries of the karst geobodies in carbonates is essential for well planning and reservoir modelling. The geohazard recognition and modelling workflows described in this paper rely on the integration of available subsurface data. Evidence of karst features was characterized with 3D seismic data, core, log and production data. Using Petrel geobody mapping techniques, the karst was picked as 3D geobodies which were then extracted based on optimized clipping parameters of the various seismic attributes. This was performed after the separation of actual signal versus noise. Several sensitivities were performed in order to optimize the final result before being integrated into a geo-cellular model.

An integrated geohazard workflow on the Bul Hanine Field revealed the presence of four distinct types of geohazards which were observed at various stratigraphic intervals. Various seismic characterization techniques were deployed to detect and map karst-related geobodies. These geobodies were then incorporated into a 3D geo-cellular model and their impact on volumes was assessed. A more detailed geohazard analysis was then performed along the trajectory of the planned wells minimizing operational risks.
New Optical Gas Imaging Technology for Quantifying Fugitive Emission Rates
Authors: Abdel-Moati Hazem , Morris Jonathan , Zeng Yousheng , Kangas Petroula , McGregor Duane
Published: December 2015

The U.S. Environmental Protection Agency (EPA) has promulgated regulations governing the detection and repair of equipment leaks that cause fugitive emissions of volatile organic compounds (VOC). These regulations are embedded in various emission standards and are generally referred to as Leak Detection and Repair (LDAR) programs. The primary method used currently in the U.S. to detect leaks is EPA Method 21.1 Method 21 requires operators to use portable instruments, typically a Flame Ionization Detector (FID) or a Photon Ionization Detector (PID), to "sniff" around the circumference of individual equipment components (e.g., valves, flanges, pump seals, etc.)2. If the detector reading (parts per million or PPM) is higher than target thresholds, the component is deemed to be leaking and it must be repaired within a certain time. Fugitive VOC emissions from a facility are calculated based upon the PPM readings (referred to as screening values or SVs) and empirical correlations between SVs and mass emission rates.2 Because the leak check is performed on each individual component basis, the implementation of a Method 21 based LDAR program is tedious, labor intensive, and prone to errors.

Optical gas imaging (OGI) technology has been developed and can be used to detect VOC leaks from process equipment. The OGI technology allows operators to use a specially designed Infrared (IR) video camera to see VOC plumes leaking from components that are not visible to the naked eye. Detecting VOC leaks using OGI is more efficient than Method 21 because leak checking using OGI is visual, making detection faster, and can be performed over an area instead of component-by-component. The OGI method allows operators to detect larger leaks easily and more frequently, achieving the same environmental benefit with a lower cost. For this reason, the OGI method is also referred to as "Smart LDAR". In December 2008, U.S. EPA promulgated the "Alternative Work Practice" (AWP) rule allowing operators to use OGI for LDAR compliance.3 However, the AWP rule requires operators to continue to perform leak checks using Method 21 at least once a year.

Although OGI can be very effective in detecting leaks, it does not provide a quantitative measure of leak rate. This has been one of the shortcomings of OGI from a regulatory perspective, thereby hindering its adoption as a true alternative to Method 21. This paper describes development of quantitative OGI (QOGI) technology. Existing OGI camera technology is the basis the new GOCI technology. If an OGI camera detects a leak, then, the operator can apply the new QOGI technology quantify the mass leak rate from the captured video images.
Innovative Initiatives in Increasing Gas & Oil Production from Sour Brownfield Facility (EPF-50) and Other Upcoming Non-Associated Gas Projects of Kuwait Oil Company
Authors: Al-Kandari Ali , Mirza Babar
Published: December 2015

The paper outlines Kuwait Oil Company’s (KOC) series of initiatives undertaken towards achieving company’s strategic target of 1 BSCFD non-associated gas and 300 MBOPD light oil by 2021/22. The initiatives include facility and integrity enhancements of its recently acquired Early Production Facility EPF-50, three new temporary Jurassic production facilities (JPF-I, II & III) to be leased and operated by contractor, as well as two major upcoming Jurassic gas facilities (JGF-I & II) for handling sour field gas & crude of north Kuwait area.

Mainly, the paper highlights the details of four (4) innovative initiatives accomplished for increasing and sustaining gas & crude production from the existing sour brownfield EPF-50 facility and the cumulative impact of these initiatives with comparative results before and after EPF-50 modifications are presented. These initiatives respectively demonstrate the benefits of utilizing new technology (proprietary Hi-Fi trays for tower internals & related alterations), use of temporary (mobile, readily available / customized) separation equipment, novel fit-for-purpose conversion of desalting process and hydrate inhibitor technology transfer in achieving increased production with enhanced product quality. Besides, the paper briefly discusses other project initiatives like EPF-50 facility and integrity enhancement projects, presently in construction phase, and other planned temporary facilities & major Jurassic gas projects.

In conclusion, the combined effect of the four innovative initiatives adopted at EPF-50 have yielded extremely favorable results not only in enhancing gas and crude production rates but also in the quality of these vital oil & gas commodities.

Additionally, as a result of installing temporary separator facility and other modifications executed at EPF-50, the crude carry-over into gas compressor was reduced thereby ensuring its uninterrupted operational availability and consequently the flaring performance has improved and chemical treatment quality of amine is enhanced.
A Simplified Transient Multi-Phase Model for Automated Well Control Applications
Authors: Ambrus Adrian , Aarsnes Ulf Jakob Flø , Vajargah Ali Karimi , Akbari Babak , Oort Eric van
Published: December 2015

Real-time estimation of the annular pressure profile is crucial for the planning and execution of well control operations, particularly while drilling wells in formations having narrow mud windows. Currently, the industry employs either simplified heuristic techniques, or complicated and often cost prohibitive commercial simulators, which are essentially "black boxes" with no options for further change by the user. Neither of the two approaches is particularly suitable for precise real-time well control analysis or design of robust automatic well control algorithms. Therefore, a simple transient multi-phase simulator amenable to real-time applications, which can represent essential dynamics with minimal cost and computational requirements, is highly desirable.

In this paper, we present a novel reduced Drift-Flux approach to model multi-phase well control situations. The model still preserves the transient multi-phase behavior of liquids and gas in the well. The proposed formulation consists of a lumped parameter model of the pressure dynamics, a transport equation for gas bubble migration, and the associated closure relations. Together, they form a system of coupled ordinary and partial differential equations with limited complexity. We then employ an explicit numerical solution algorithm that is fast and thereby reduces computational time and cost, making it suitable for control purposes.

The validity of the model is tested against experimental data from a test well with a simulated gas kick event. The model is also compared against a well control scenario generated by a commercial multi-phase flow simulator extensively used in the industry. There is good agreement between the results of the proposed model and the experimental data, on the one hand, and the commercial simulator results, on the other, thereby justifying the applicability of this model to real-world scenarios. The model provides a powerful tool to estimate and manage the surface pressures during a well control event for a given kick size and intensity. It has evident applications in well control analysis, automated Managed Pressure Drilling and well control management. As such, it has the potential to improve well control risk mitigation, enhance rig safety, and reduce non-productive time associated with well control-related trouble events.
Distributed Acoustic Sensing (DAS) VSP for Imaging and Velocity Model Building
Authors: Nizkous I. , Gerritsen S. , Kiyashchenko D. , Joinson D.
Published: December 2015

Distributed Acoustic Sensing (DAS) deployed in multiple wells was used in Brunei for simultaneous recording of seismic signals emitted by a source grid on the surface. Such a configuration works similar to a 3D Vertical Seismic Profiling (VSP) survey with conventional geophones and provides interval velocities, time-depth relationship as well as images below the wells based on the reflected seismic rays. DAS VSP data has provided the opportunity of impacting asset performance by: (1) improving the image of the legacy 3D surface seismic by remigration using the updated shallow velocity model, thus minimizing both the structural as well as the depth uncertainty, and by (2) providing compelling DAS-only 2D and 3D images beneath the wells with higher resolution than the surface seismic. These can be employed for the reservoir static and dynamic model update and identification of sub-surface seismic faults and/or other events. Additionally, this technology presents the possibility of fluid monitoring in this type of reservoir where production is supported by water injection.
Competency Based New Hires Roadmap; A Case Study of Kuwait Oil Company
Authors: Al-Daihani Eisa Hadi , Nandi Arun Kumar , Matar Maqhim Bander , Raza Syed Mohammad
Published: December 2015

Competency is the ability to apply knowledge and skills to perform a specific task effectively and consistently within time frame and demonstrated by relevant behavior. Levels of competencies with knowledge and skills defined separately have been identified under different job families in Kuwait Oil Company (KOC) like Geoscience, Petroleum, Reservoir and Drilling Engineering. These competency levels can be equated with 4 internationally recognized levels of competencies i.e. Awareness, Basic Application, Skilled Application and Mastery.

The desire towards international standards of performance and increasing nationalization of technical manpower has caused a major shift in how the oil and gas industry trains and develops its workforce. Like Kuwait Oil Company, many companies are facing problems due to bimodal age distribution of their technical manpower i.e. a sizeable group of experienced personnel are close to their retirement age and a large pool of young professionals and new hires are joining the oil and gas sector with no or very little practical exposure. As a result there is a significant shortage of fully qualified, mid-level technical workforce to bridge this generation gap. Therefore, the need of the hour is a fast track development of these new hires to equip them with sufficient knowledge and skills in a shortest possible time.

In view of above objective, a competency based new hire's roadmap has been designed by KOC. The present paper has come out with an approach which is being implemented successfully to develop new hires on fast track basis. It involves four stages namely Familiarization, Customized Workshops (Discipline wise), Mandatory Foundation Assignments (MFA) and Career Path Oriented Project. After completion of the New Hires Roadmap, a technical employee may attain the competency level where He or She can perform routine tasks and related assignments independently.
Lessons Learnt From a 3D Seismic Reprocessing in a Middle East Carbonate Field
Authors: Pernia Soto L. R. , Brunellière J. , Piazza J. L. , Chenot D. , Toubiana H. , Gigou G.
Published: December 2015

This paper presents the lessons learnt from a seismic reprocessing performed to improve the seismic reservoir characterization of a Middle East carbonate reservoir. The reservoir characterization objective is to optimize the porosity modeling driven by seismic data; hence, improving seismic amplitudes was crucial as they drive the inversion process for elastic properties. The new seismic reprocessing sequence was focused on the restoration of genuine primary amplitudes and improvement of the angle stacks design at the reservoir. In order to monitor the seismic amplitudes quality improvement throughout the processing sequence, a thorough quality assessment strategy has been implemented for decision making. It has allowed adjusting the amount of testing depending on the quality of intermediate results at selected key steps. The results obtained by using this QC strategy showed the importance to monitor in details the amplitudes quality progress by tuning at an early time the processing parameters that impact all the remaining steps. At the end of the reprocessing, a cleaner dataset, less affected by multiples interferences, with a more consistent amplitude balance and optimized angle stacks design has been obtained. It is deemed to be more appropriate for pre-stack inversion purposes in view of seismic reservoir characterization.
Development and Infill of the Late Albian to Turonian Shilaif Intrashelf Basin at the Eastern Margin of the Giant Mesozoic Arabian Carbonate Platform: Basin Architecture and Time Stratigraphy
Authors: Vahrenkamp V. , Franco B. J. , Popa D. , Barata J. , Grelaud C. , Razin P. , Grosheny D. , Bulot L.
Published: December 2015

The Upper Cretaceous Shilaif intra-shelf basin at the eastern margin of the Arabian platform contains rich source rock sequences in the hydrocarbon generation window, which are targets for ongoing exploration work. Time stratigraphy and sedimentology are key components to unravel the complex development of the hydrocarbon system. This paper presents detailed bio-, chemo- and sequence-stratigraphic data in combination with sedimentological analysis from core, well, seismic and outcrop data to support an analysis of basin architecture and regional time stratigraphic correlations.

The Late Albian to Turonian saw the final intra-shelf basin development and infill on the eastern margin of the Arabian plate Cretaceous carbonate platform. Basin development began with the deposition of the Late Albian Mauddud Formation. Mauddud cycles are laterally continuous over large distances but thin in western and central Abu Dhabi in the area of the future intra-shelf basin. Differential aggradation is likely to have been accentuated by unfavorable climatic and water-quality conditions related to the Albian/Cenomanian Oceanic Anoxic Event.

The Mauddud is overlain in the west and east of Abu Dhabi by the shallow marine aggrading & prograding carbonates of the Mishrif Formation with a SSW-NNE elongated intrashelf basin forming in central Abu Dhabi. This basin is filled by the Shilaif, Tuwayil and Ruwaydah Formations. Four depositional sequences with organic rich intervals are recognized in the Shilaif Fm corresponding in time to pulses of aggradation, progradation and retrogradation of Mishrif shallow-water platform margin sediments.

The Tuwayil is a shaly lowstand/transgressional sequence onlapping onto the Mishrif, which was at this time partially exposed based on erosional channel incisions on the platform top. The Ruwaydah Fm is composed significantly of calcispheres recording continued transgression, increased accomodation space and an increase of carbonate production. The Coniacian Laffan shales unconformably overlie the Cenomanian/Turonian sedimentary sequences.

Basin-fill sequences have been age dated with detailed chemo- and biostratigraphy. Based on carbon isotopes the Mauddud predates/coincides with the OAE at the Albian/Cenomanian boundary and is hence late Albian. Other carbon peaks, ammonites, calcispheres and planktonic foraminifera align the Shilaif with the Cenomanian reaching near its top the Cenomanian/Turonian boundary. The Tuwayil and Ruwaydah Fms are Turonian.
4D Seismic in Stacked Reservoirs - from Puzzles to Insights on Production Drive Mechanisms
Authors: Kiyashchenko Denis , Norzalenna Haji Puasa Siti , Field Chris , Skogly Odd Petter , Suut Suria
Published: December 2015

Time-lapse seismic is used to monitor production for an offshore Brunei oil field (Field ‘M’). Several unusual observations have been made there - aquifer softening, considerable gas cap growth despite small reservoir pressure changes, and oil rim softening signals interpreted as a signature of aquifer water ingress. These observations suggested a new reservoir drive mechanism based on gas migrating from other blocks and charging gas caps.
Protecting and Commercializing Oil and Gas Technology: Recent Developments in Intelligent Energy Law
Authors: Fraser Hugh
Published: December 2015

Intelligent Energy Law is a key element of the continuing progression of "Intelligent Energy" solutions and innovations. It can be defined as the strategic planning and application of international law and contracts to maximize investment returns on advanced technology and know-how through the creation, acquisition, commercialization and protection of intellectual property.
Evaluation and Application of Novel Technologies and their Impact on Sustained Gas Production in Saudi Arabian Reservoirs: Field Examples
Authors: Rahim Zillur , Al Kanaan Adnan A. , Al-Anazi Hamoud , Al-Malki Bandar , Kayumov Rifat , Al-Jalal Ziad
Published: December 2015

Stimulation treatments in Saudi Arabian gas reservoirs were initiated in 1998. Since then, stimulation gradually became the preferred technology to improve gas production and sustainability. Different technologies have been applied over the years, and only the best of them survived the test of time. Advances in completion technologies enabled drilling horizontal wells and completing them with multistage stimulation completions in either openhole (OH) or cased hole wellbores. The new generation of stimulation software allowed comprehensive modeling of hydraulic fracturing in a 3D reservoir simulation software platform. Advances in logging technologies allowed better estimation of rock mechanical properties, a major input for the fracturing design software. Channel fracturing technology mitigated the risk of screenout in proppant fracturing and enabled placing fractures with nearly infinite conductivity that helped in faster cleanup of the well and improved production. The new dualcrosslinked fracturing fluid provided a reliable solution for high-pressure/ high-temperature (HPHT) reservoirs that can sustain very high shear degradation. Viscoelastic surfactant (VES) based fracturing fluid limited fracture height growth, thereby allowing hydraulic fracturing in pay zones with nearby water zones. Emulsified acid allowed live acid to penetrate deeper into the reservoir. Fiber laden viscoelastic self-diverting acid proved to be an efficient diverting technique for matrix acidizing and acid fracturing. This paper provides an overview of the different technologies that make stimulation treatments highly successful.
A Case Study on Miscible and Immiscible Gas Injection Pilots in Middle East Carbonate Reservoir in an Offshore Environment
Authors: Kumar Jitendra , Agrawal Pawan , Draoui Elyes
Published: December 2015

Hydrocarbon gas injection is the most widely applied process after waterflooding, and is a promising enhanced oil recovery (EOR) injectant for use in Middle East carbonate oil fields. Gas injection improves microscopic displacement efficiency and generally acts as pressure maintenance; however, unfavorable mobility ratio can negatively impact the ultimate recovery due to viscous fingering and gravity override.

This paper describes two gas injection pilots that have been implemented in offshore Middle-East carbonate reservoirs, a secondary and a tertiary gas injection through line drive to assess injectivity, productivity, macroscopic sweep efficiency, flow assurance and operational efficiency in a field that has long water-injection history. A strong monitoring plan, including an observer well, was applied through time-lapse saturation logging, pressure measurements, production testing, tracer campaign, etc. to evaluate the pilot efficiency and address key uncertainties upfront prior to full-field application.

This paper describes the pilot performance in the context of full-field development, local and macroscopic displacement efficiency, flow assurance issues, and operational learnings. The gas injection performance is strongly impacted by reservoir heterogeneity, gravity segregation and the existing pressure gradient, and the history match performed indicates near-miscible or miscible behavior depending upon local pressure regimes, which thus govern the ultimate recovery. The history match also shows that for the same pilot, performance can be further improved through water-alternating-gas (WAG) injection, resulting in a viable development scheme for full-field implementation.
WellCON: Early Kick Detection System Extended to Kill Sheet
Authors: Velmurugan Naveen , Bansal Gopal , Sharma Tushar
Published: December 2015

The work described in this paper is an extension of one part of the early kick detection system WellCON created by the authors of this paper. The work aims at the working of the gas kick detection system of WellCON and extend it to the preparation of a kill sheet by the model which provides information regarding the kill mud density, maximum limit of kill mud density, circulation pressures, time to bit to circulate the kill mud, etc. Physical phenomenon of sonic wave propogation in a medium is the basis of the work which provides information about the wellbore based on the travel time of these waves. This work aims at automation of the BOP closure procedures based on the early kick detection and also provide with the required information to kill the well. This faster and automated procedure is expected to help provide a safe working place and also minimize the loss due to kicks.
Flow Accelerated Corrosion in Boilers/HRSGs
Authors: Shashidhar V , Patnaik Debi
Published: December 2015

Combined life cycle heat recovery steam generators (HRSG) play a vital role in energy efficiency, reducing green house effect. More than 40% of Heat Recovery Steam Generator (HRSG) tube failures are due to Flow Accelerated Corrosion (FAC).The FAC phenomenon occurs in carbon & low alloy steels, with poor chemical treatment & design. Identification, mitigation & preventive action of FAC is vital to improve boiler performance. This paper provides some insight to factors influencing FAC & their control through a case study at Qatargas.
Fluid Field Analysis and Parameter Optimization of a Coalescence-Cyclone Separator
Authors: Zhao Lixin , Zhao Wenjun , Xu Baorui , Jiang Minghu
Published: December 2015

In order to improve the separation efficiency of the hydrocyclone, a new type of cyclone separator is proposed. According to computational fluid dynamics method, a new cyclone separator, coalescence-cyclone separator, is numerically simulated by Fluent software based on a co-rotating outflow reverse-cone hydrocyclone, and is compared with the co-rotating outflow reverse-cone hydrocyclone. Inlet flowrate, inter oil volume fraction and tangential outlet split ratio of the coalescence-cyclone separator were researched.
The Impact of Increasing Depth and Diameter on Prediction of Flow Regime Transition in Deepwater Flowlines and Risers
Authors: Okereke N. U. , Kara F. , Omowunmi S. C. , Oyawale M. , Adefemi I.
Published: December 2015

This work is based on simulation of a typical deepwater oil field in West-Africa over 1000m depth, which is subject to hydrodynamic slugging at its early life. Sensitivity analysis was carried out to simulate the impact of increasing depth and diameter on the field with the same fluid composition and slight variation in pressure and mass flow conditions.

Based on US MMS, fields found in water depth of 1000 ft (305m) and above are termed deepwater fields. Typically, for deepwater oil fields the ambient temperature is low giving room for formation of compounds such as hydrates and wax. Also of critical concern is the increasing depth associated with deepwater oil fields which leads to increasing hydrostatic pressure and its associated tendency for slugging formation. Increasing diameter has the tendency to lead to a drop in fluid velocity. However, there are still speculations as to the exact effect of increasing diameter on flow instability which is one of the main aspects of the present work [1].

An understanding of the multiphase flow phenomenon as well as the overall potential effects on the processing facilities is required in the design of the multiphase flowlines. An under-design or overdesign of the piping can be counterproductive and may significantly affect the process plant operability. Therefore emphasis is placed on understanding completely, flow assurance issues in the multiphase flow; especially slugging phenomenon as flowline-riser system diameter and depth is increased.
Development of Integrated Workflows to Increase the Value of Surveillance Data (iGEMS)
Authors: Al-Mohannadi Muna , Al-Kuwari Ahmed , Al-Mohannadi Abdulaziz , Al-Tayeb Amna , Al-Mannai Ahmad , Landis Lester , Nivarthi Sriram , Paez Rachel
Published: December 2015

An important objective of a surveillance programme for a gas condensate reservoir is to accurately assess reservoir pressure depletion over time. However, partial-to-complete isolation of zones throughout such a reservoir complicates the collection and interpretation of reservoir pressures from pressure transient analyses alone. As a result, production logs are run to obtain zonal flow contributions to understand the status of zonal pressure depletion. Understanding these zonal contributions and their implications on zonal pressures requires an integrated knowledge of the geologic and operational controls on flow.

Integrated Geologic and Engineering Modeling Studies (iGEMS) is a workflow designed to provide this integration and, thereby, increase the value of surveillance data. iGEMS focuses on identifying well-level geologic and operation controls on flow. iGEMS uses an efficient process to rapidly create, run, and analyze single-well simulations that include the effects of boundary pressures and compositions inherent in the parent model.

A case study utilising the iGEMS workflow is covered in this paper. This case study provides a specific example of how iGEMS teams identify geologic and operational controls on reservoir performance and develop a better understanding of zonal pressure differences. iGEMS provides insights on these controls by using reservoir modeling as a tool to integrate surveillance data, well logs, core data and geologic observations. Understanding what is controlling flow in the reservoir helps engineers, geoscientists, and petrophysicists make better operating decisions to maximise reservoir performance.
Integrated Study To Exploration Success
Authors: Kerboub Azibi Zohra
Published: December 2015

This paper involves integration of data from various sources and of different scales (geology, seismic, borehole logs, cores and dynamic fluid information) which helps to properly characterize a reservoir and to build a reliable static model.

Reservoir characterization and modeling are most important part of all aspects related to the field development and also to the exploration. It can help to reduce the risks and to increase resources. It is an important multidisciplinary approach which allows reaching a reliable prediction and a better understanding of our reservoir and its heterogeneities which have a big impact on the fluid drainage.

This study consists in characterization and modelling the Triassic reservoirs of Oued Mya basin in order to define the best zones where to drill exploration and appraisal wells. The distribution of the reservoir sands across the field is considered to represent the greatest geological uncertainty in a depositional fluvial environment.

The deposition of the Triassic reservoirs occurred in an overall transgressive episode during the Late Triassic as fluvial valley fill and braid-plain quartz sandstones and eolian quartz sandstones. In such a system the channel sand-bodies display extensive heterogeneity and the prediction of net sand distribution is difficult.

According to the well logs evaluation those reservoirs are oil bearing in some studied wells, and some others are tight or water bearing situated structurally deeper. The sedimentological model which represents best the environment of our area of study subjected to the modeling would consist of two braided systems.
Environmental Footprint of GTL Fuel Usage
Authors: Viljoen J. H. , von Berg G. F.
Published: December 2015

ORYX GTL, a joint venture between Qatar Petroleum and Sasol Synfuels International is located in Ras Laffan industrial city in Qatar. Gas-to-Liquids (GTL) is a technology to convert natural gas into high-performing, ultra-clean liquid fuels utilizing the Fischer-Tropsch reaction.

The objective of this paper is to share the results of the demonstration under local environmental and normal operating conditions of running diesel engines on GTL Diesel, and benefits identified.

The project was a coordinated effort between government departments, industry and academia, to run two controlled sets of diesel buses for a three month period; one set of ten buses on fossil fuel (conventional diesel) and the other set of ten buses on GTL Diesel in and around Doha, Qatar. The buses travelled approximately 10,000 km each. Experiments conducted included consumption monitoring, oil sampling and analysis, exhaust smoke testing, laboratory static engine testing and fuel characterisation. In order to maintain integrity of the results, an independent party was appointed to oversee the process.

Engine oil sampled from the buses fuelled with conventional diesel contained visibly higher levels of sediments and was more viscous compared to the engine oil sampled from the GTL fuelled buses. Smoke tests conducted on the GTL fuelled buses yielded significantly lower smoke density compared to the results from the conventional diesel fuelled buses. The results of the fuel consumption comparison between the two sets of buses, have been in line with expectations. The results from static engine laboratory testing has been very positive indicating lower emissions from the engines running on GTL fuel.

Based on the results, GTL fuel exhibits less engine wear, slower degradation of the oil, cleaner emissions, and similar consumption compared to fossil fuelled engines. The overall project has served to highlight to multiple parties in the community the benefits of GTL fuel.

This type of experiment was conducted for the first time in the conditions of the Arabian Gulf. It has demonstrated that GTL fuel is a viable alternative with environmental and operational benefits.
Operations Excellence Begins in Design
Authors: Qualls Wesley R.
Published: December 2015

This article will explore operational concerns common to the LNG industry and provide insight into analysis, methods and techniques to employ throughout the design process to help ensure trouble free life-cycle operation.

Achieving production and availability targets is paramount to the ultimate success of any LNG project. Both are important factors in any life-cycle economic analysis. Clearly, meeting these targets is in both the owner's and operator's best interest. For that reason, most major projects conduct detailed Reliability, Availability and Maintainability (RAM) studies during design, both to gain comfort with the design and to satisfy project financiers. However, certain assumptions are implicit in any RAM study with some examples provided below. All contaminants have been identified and addressed to avoid foaming, degradation, accelerated or unexpected corrosion, freezing, or a failure to meet product specifications.Equipment and piping are sized to operate over the full range of feed and ambient conditions.Control valve sizes, trim selections and instrument ranges are adequate for the full range of conditions without resulting in process instabilities.Piping sizes, routing and supports are selected to eliminate or address transient conditions and unstable flow regimes.Storage and inventory requirements are sufficient to support initial startup and routine maintenance operations.

A general industry observation is that several key assumptions necessary to achieve the expected life-cycle RAM results are often incorrect. Since the expectations remain in place, operating companies are sometimes forced to address and correct design deficiencies. While some may be addressed through alternate controls, operational strategies, or otherwise simple fixes, others may require much more effort.

The focus on true operational excellence must begin early in the design phase and remain endemic throughout. This paper will focus on common design pitfalls and oversights within the LNG industry and present several methods or techniques to avoid. While the techniques/methods presented are not new or novel to the oil and gas industry as a whole, they are often not utilized within the LNG industry. In fact, in some cases, very well established techniques pioneered by previous engineering generations could be utilized to avoid design pitfalls are omitted entirely from the design process. This paper will focus on a few key methods and techniques to achieve design expectations and operational excellence.
Development and Qualification of a Next Generation Gas Tight Connection Incorporating Metal-to-Metal Technology
Authors: Bassarath W. , Lafuente M. , Branly R.
Published: December 2015

The Oil & Gas industry has an increasing demand for gas tight connections, particularly in deepwater applications such as in the Gulf of Mexico. These connections incorporate metal-to-metal seals and have been been motivated by wells requiring high-pressure completions/stimulations, drill stem testing, managed pressure/under-balanced drilling applications and wellbore cleanout assemblies. In response to customer requests, a new gas tight connection with a metal-to-metal rotary seal was developed. When developing this connection with high pressure gas tight capability, a no compromise approach was mandatory since safety and well integrity were primary concerns. This product can be utilized for both drilling and completion operations, so it represents a considerable cost saving due to improved operational efficiency.

This paper details the development and qualification of this new connection. In the development of this new connector Finite Element Analysis (FEA) was used, resulting in a product that is a hybridized version of a premium double shoulder connection and the gas tight connection from a drill-pipe-riser. The connection therefore provides the high pressure capability of premium casing or tubing connections coupled with the robustness and increased torsional strength associated with a double shoulder rotary connection. Qualification of the new product was performed on the most critical sizes and involved industry standard physical testing including make & break, overtorque, combined loading and fatigue testing. In fact, a staunch safety commitment has allowed it to provide one of the highest operating margins of any gas tight connection and is qualified to 30,000 psi internal pressure and 25,000 psi external pressure. The full qualification results are detailed and discussed in the following pages.