bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production Performance of Gas Condensate Reservoirs: Compositional Numerical Model - A Case Study of Hai Thach - Moc Tinh Fields
Authors: Tran T.V. , Ngo A. T. , Hoang H. M. , Tran N. H. 
Published: November 2015

Abstract
The approach focuses on the use of analytical and 3D dynamic compositional numerical models to physically describe the condensate banking phenomenon and to better understand the real deliverability in terms of gas and condensate production. The model is also built to compare the benefits of hydraulic fracturing over the horizontal well in Bien Dong POC development campaign.
In this study, an analysis of pressure transient test data is conducted to investigate the condensate bank radius. Construction of a radial model is used as a benchmark model to compare it to an equivalent Cartesian grid model in term of productivity. The paper is focused on the development of a workflow for the analysis and selection of grid size and methods used in the 3D compositional model. Then the model is used for horizontal and hydraulic fracturing designs.
When the flowing bottomhole pressure falls below dew point, the condensate dropouts in the near wellbore reduce permeability to gas through relative permeability effects; hence the well productivity is reduced significantly. The prediction of gas condensate well production will strongly depend on condensate banking evaluation and modeling. It is important that a model is built to describe the condensate banking phenomenon accurately to avoid over-estimating well performance. It is shown that an integrated model which incorporates Generalized Pseudo Pressure (GPP) and Local Grid Refinement (LGRs) can reproduce almost exactly with the benchmark model. The presented procedure and analysis can serve as a guideline for full field gas condensate reservoir modeling. The study also suggests that un-fractured horizontal well is not attractive compared to hydraulic fractured vertical well. Fractured half-length optimization design should be based on economic criterion.
The study addresses the complexity of gas condensate behavior around the near wellbore region. The workflow of building an accurate 3D compositional model allows Bien Dong POC to have a reliable resource in reservoir development and management plans.
The applicability of this work is confirmed by actual field case study in offshore Vietnam. It contributes to the knowledge of performance of gas condensate reservoirs and supports representative modeling of detailed model and recovery processes.
Analogue Modelling of Shah Structure in Abu Dhabi; Mode and Structural Evolution
Authors: Koyi Hemin , Sirat Manhal , Morad Daniel 
Published: November 2015

Abstract
Three-dimensional seismic data have been used to construct a series of scaled analogue models simulating the structural evolution of the Shah hydrocarbon Field. Models consisted of a set of layers of loose sand on two basal plates whose contact simulated a basement fault. Depositional history of the Shah structure was simulated in the model by producing syn-kinematic deposition and erosion. Deformation of the model was achieved by moving one of the basement plates in a way that it initiated an oblique slip along the basement fault. This oblique movement induced both a strike slip movement in and shortening of the cover sand layers, which resulted in formation of an open anticline (box fold) along the strike of the fault similar to the Shah structure.
The 3D seismic mapping of the Shah hydrocarbon Field reveals carbonates dominating lithological units from the Pre Khuff Fm (Permian) to the Dammam Fm (Eocene). A major unconformity in the stratigraphy indicates uplift, exhumation and erosion at Simsima level (U. Cretaceous) with onlapping of the younger units (Eocene-Miocene Formations). The Shah structure is an open SW-NE striking anticline, which changes symmetry along strike; asymmetric in the SW, more symmetric in the middle, and asymmetric open anticline in the NE. Model results indicate that the structure is a basement related cover anticline formed due to the oblique movement along a basement fault, which was reactivated during the obduction of Semail Ophiolite and later collision of Arabia with Iranian plate. These results show that this anticline formed without the need for a shortening component perpendicular to the strike of the structure. An oblique slip along a basement fault, with a relatively small degree of shortening could equally well result in the formation of such open and low-amplitude anticline.
The modelling results presented here provides an alternative scenario for the formation of Shah structure (low-amplitude, and open) and addresses some of the key questions about its structural constraints (e.g. geometry, timing and evolution history) by linking it with basement structures. Our modelling results are of high significance for understanding entrapment mechanism, migration pathways, and fracture development. This newly proposed mechanism impacts the exploration and development of the Onshore Fields in Abu Dhabi, at the vicinity of Shah Structure.
Organic/Inorganic Deposition in Oil Producing Wells from Carbonate Reservoirs: Mechanisms, Removal and Mitigation
Authors: Al-Taq Ali A. , Muhaish Salah A. , Nakhli Maithem M. , Alrustum Abdullah A. 
Published: November 2015

Abstract
Several wells in a carbonate reservoir have experienced significant reduction in their oil productivity. Bailer samples collected from these wells showed that they were damaged with organic/inorganic deposition. Analysis of the collected material showed that the organic deposits consisted of asphaltene and associated paraffins while the inorganic deposits were mainly calcite with ankerite, anhydrite and small amounts of quartz and halite.
The formation of calcium carbonate scale is anticipated to occur due to CO2 degassing during production. In addition, these wells produce commingled oil from two carbonate reservoirs which allow their formation waters to mix together; therefore, scaling tendency prediction showed a positive saturation index for calcium carbonate. The sulfate scale in the form of anhydrite is anticipated to be formed due to mixing of high sulfate source (seawater), used to maintain reservoir pressure, with a calcium rich source (formation water).
The colloidal instability index from SARA analysis indicated that the reservoir oil in this field has a moderate instability to potentially precipitate asphaltenes. Additionally, the interaction of low pH scale inhibitor with the formation oil and presence of charged particles such as calcite will destabilize asphaltenes in oil.
Two techniques were examined toward dissolving the organic/inorganic deposition including a two-stage and a single-stage method. The two-stage method involves the use of solvent preflush to remove the organic coating material from the whole deposits followed with the use of HCl acid to remove the remaining inorganic deposits. An emulsified HCl acid/solvent is used in the single stage method to remove the whole deposits.
The paper discusses different analytical techniques used to identify the nature of the damaging material, mechanism of organic/inorganic deposition, and the optimization of dissolver/solvent systems to remove formation damage and restore productivity of damaged wells. It also assesses and optimizes the current used scale inhibitor squeeze (SIS) treatment program.
Cost and Weight Reduction by Choosing Aluminium for Offshore Structures
Authors: Jongejan Maarten , Mackintosh Amanda , de Kluijver Dick 
Published: November 2015

Abstract
As weight issues become increasingly apparent within the offshore construction industry, aluminium is gaining attention. By constructing large offshore platform/vessel parts from aluminium, the reduction in weight is significant: up to 60% less than steel. Replacing steel construction with full aluminium structures is not entirely feasible; thus the path forward lies in working with aluminium and steel together. Fabricating with aluminium requires a different approach starting with the earliest stages of the project. Only with innovative, out-of-the-box thinking can we use the attributes of aluminium to the fullest extent. Aluminium has valuable benefits; particularly in the harsh and highly corrosive seawater environment, for example, aluminium alloys used in the offshore industry corrode 100 times slower than steel, thus requiring little to no maintenance, resulting in a durable structure with a very low cost of ownership.
In general, an aluminium construction always outlives the platform. Despite all those great benefits, there are quite a number of preconceptions around using this material in construction projects; such as its behaviour in a fire, the complexity of welding, and its price. In this paper, we will address these assumptions and clear up popular misconceptions.
Inversion of Wireline Formation Tester Data to Estimate In-Situ Relative Permeability and Capillary Pressure
Authors: Cig Koksal , Ayan Cosan , Kristensen Morten , Liang Lin , El Battawy Ahmed , Elshahawi Hani , Ramaswami Shyam , Mackay Eric 
Published: November 2015

Abstract
Relative permeability and capillary pressure curves are crucial inputs for a reservoir description. However, measuring these quantities on core samples in the laboratory is an extensive and time-consuming process. Wireline Formation Tester (WFT) logging is routinely applied in field operations for reservoir evaluation purposes. Often a historical record of WFT data exists for a field which can be re-interpreted, and since this interpretation takes days, rather than months to years in the case of core analysis, we propose in this paper to revisit the acquired WFT data with the purpose of estimating multiphase flow properties.
WFT logging is generally conducted in an open hole environment. By the time of logging, the near-wellbore region has been exposed to mud filtrate invasion. In the case of immiscible mud filtrate and formation fluid the invasion resembles a small scale water-flood process. During WFT sampling the mud filtrate is first cleaned and formation fluid subsequently sampled in a multiphase flow environment while measuring bottom-hole pressures and water-cuts. As shown in previous papers (Cig et al., 2014, 2015), the measured WFT data can be utilized in an inversion workflow to estimate relative permeabilities by combining a forward model of the cleanup process with an optimization engine.
The proposed methodology starts with an open hole log interpretation which provides reservoir properties including a saturation distribution. The filtrate invasion is represented as accurate as possible from the open hole logs and drilling reports. WFT tool geometry and its internal tool storage and fluid segregation effects are incorporated into the modeling. A numerical forward model is then simulated within an optimization workflow where relative permeabilities, capillary pressures, damage skin, and depth of mud filtrate invasion are estimated by minimizing a misfit function between measured and modeled bottom-hole pressures and water-cuts. Industry accepted parameterization techniques are used for the relative permeability and capillary pressure curves. Initial parameter estimates are provided from the interpretations of the open hole logs, such as resistivity, dielectric, nuclear magnetic resonance, as well as from pressure transient analysis.
Previously we have studied WFT data from a 3D radial probe (3DRP) and a dual packer (DP) (Cig et al., 2014, 2015). The proposed methodology was also validated with synthetic datasets in the same papers. In this paper we extend the methodology to a single probe (SP) inlet and to joint inversion of both capillary pressure and relative permeability curves. We demonstrate the methodology using field data from a Central Asian clastic reservoir. Interpretation of multiphase flow properties from WFT data represents a valuable complement to core measurements and will help to condition reservoir models for more reliable forecasting.
Stimulating The Giants: Carbonate Acid Stimulation Design in Horizontal Open Hole and ICD Completions
Authors: Clemens C. , Kutty S. M. , Zidan M. F. , Tajuddin M. S. 
Published: November 2015

Abstract
A stimulation optimization study was recently conducted to design the acid recipes and execution programs for a new carbonate field in Abu Dhabi. The following paper outlines lessons learned and technical considerations that can improve the stimulation design of carbonate reservoirs. This particular field has a variety of extended horizontal completions ranging from open hole drains to liners with inflow control devices (ICDs). The following testing format can lead to immediate cost savings and long-term production increases in both green and brown fields. The Reservoir and Operation teams leveraged their expertise to place science firmly behind this important aspect of bringing a new field online. By being exact about the recipe testing procedure, the team made technical improvements to the existing recipes while also lowering the cost of stimulation.
Incorporation of Climate Change Mitigation and Adaptation in Environmental Impact Assessment
Authors: Reddy Vijaya Bhasker , Al Bisher Khalid , Monaghan David 
Published: November 2015

Abstract
Major developmental activities, such as power generation, mining, manufacturing, oil and gas exploration, transportation and infrastructure projects, result in large scale release of Green House Gases (GHG) (i.e. carbon dioxide (CO2), methane (CH4), Sulphur Hexafluoride (SF6) and nitrous oxide (N2O)). Release of these gases affect climate change indirectly and pose a serious challenge to global development and project planning due to uncertainty of the climate change impacts.
Traditionally, projects are assessed for their potential impact on the environment. Often climate change mitigation and adaptation aspects have not been considered during the project life cycle impact assessment.
Reducing GHG emissions continues to be one of the main policy drivers to meet the Kyoto Protocol targets and commitments under various climate change conventions. Current Environmental Impact Assessment (EIA) methodology focuses on conventional pollutant discharges. Climate change due to GHG emissions are not considered as a pollution issue. This paper explores the opportunities and challenges in integrating climate change as a consideration that can be embedded in the EIA process.
After 14 years of Water Flooding a Giant Reservoir in North Kuwait: Lessons Learnt, Experiences Gained and Way Forward
Authors: Chetri Hom , Al-Quene Amna , Jamal Mariam , Al-Zaabi Hamad 
Published: November 2015

Abstract
The Sabiriyah Mauddud limestone is a super-giant depletion drive oil reservoir in North Kuwait. It is undergoing massive development efforts, with a planned enhancement in oil production through phased water flood development since 2000.
The Phase1 development addresses the crestal area (60 km2) of the structure, which was the focus for development efforts in the past. 14 years of dynamic performance from producers and injectors located in the Ph1 area enhanced the understanding of the reservoir dynamics. Time lapsed monitoring of static reservoir pressures at key wells during the ongoing water flood, coupled with isochronal Pressure surveys during reservoir shut-downs and RFT data from newly drilled wells in the area during the post injection period, helped to confirm the pressure connectivity across the reservoir and the water flood response. As all the wells are on ESP, the live data on Pump-intake Pressures provided insights into response behavior. Production tests gave valuable insights into the well performance, specially water cut build-up and reservoir architecture. Integration of the dynamic data with Production logs & FMIs led to the identification of speed zones with high permeability. One of the limitations of the pattern water flood with a combination of vertical injectors & vertical producers perforated across the whole hydrodynamic unit was a quick water breakthrough via the high perm speed zones and re-circulation of the injected water, as evident from tracer surveys and PLT data. A comprehensive review and updated performance analysis led to the need of re-developing the reservoir with a paradigm shift using a combination of Horizontal injectors drilled & completed at bottom of the hydraulic unit and the horizontal producers drilled/ completed at upper part so that the water breakthrough is delayed and better sweep is achieved. A conformance plan has been taken up so as to switch over to the new strategy.
The Phase2 development consists of all remaining peripheral acreage (250 km2), with immense reservoir rock & fluid uncertainties, leading to the identification of reservoir segments for re-appraisal through drilling & testing of new wells. Re-appraisal work, along with enhanced fluid description, led to the conclusion that a large segment within the Ph2 area, originally considered as a regime of light oil - turned out to be viscous oil with a high pressure ramp. In addition to helping the ongoing Full field dynamic modeling and development planning for this giant reservoir, this also led to the initiation of a peripheral Water flood with vertical wells initially, and switching over to Non-Conventional Wells in the poorer Ph2 area.
This paper documents the case history of Waterflood management in a super-giant carbonate reservoir and the challenges that had to be met with a quick re-adjustment to the development plan as necessitated during the ongoing implementation & evaluation.
Reduced Polymer Loading, High Temperature Fracturing Fluids using Nano-crosslinkers
Authors: Liang Feng , Al-Muntasheri Ghaithan , Ow Hooisweng , Cox Jason 
Published: November 2015

Abstract
In the quest to discover more natural gas resources, considerable attention has been devoted to finding and extracting gas locked within tight formations with permeability in the nanoto microdarcy range. The main challenges associated with working in such formations are the intrinsically high temperature and high pressure bottom hole conditions. For formations with bottom hole temperatures around 350-400°F, traditional hydraulic fracturing fluids that use crosslinked polysaccharide gels, such as guar and its derivatives, are not suitable because of significant polymer breakdown in this temperature range. Fracturing fluids that can work at these temperatures require thermally stable synthetic polymers such as acrylamide-based polymers. However, such polymers have to be employed at very high concentrations in order to suspend proppants. The high polymer concentrations make it very difficult to completely degrade at the end of a fracturing operation. As a consequence, formation damage by polymer residue can block formation conductivity to gas flow.
This paper addresses the shortcomings of the current state-of-the-art high temperature fracturing fluids, and focuses on developing a less damaging, high-temperature stable fluid that can be used at temperatures up to 400°F. A laboratory study was conducted with this novel system which is comprised of a synthetic acrylamide-based copolymer gelling agent and is capable of being crosslinked with a nano-sized particulate crosslinker (nano-crosslinker). The laboratory data has demonstrated that the temperature stability of the crosslinked fluid is much better than a similar fluid lacking the nano-crosslinker. The nano-crosslinker allows the novel fluid system to operate at significantly lower polymer concentrations (25 to 45 pptg) when compared to current commercial fluid systems (50 to 87 pptg) designed for temperatures from 350°F to 400°F. This paper presents results from rheological studies which demonstrate superior crosslinking performance and thermal stability in this temperature range. This fracturing fluid system has sufficient proppant carrying viscosity, and allows for efficient cleanup using an oxidizer-type breaker. Low polymer loading and little or no polymer residue are anticipated to facilitate efficient cleanup, reduced formation damage, better fluid conductivity and enhanced production rates. Laboratory results from proppant-pack regained conductivity tests are also presented.
Implementing Data Management Solutions within a Massive Greenfield Start up –A Case History, Onshore UAE
Authors: Uniyal Parashu , Al Blooshi Ahmed , Al Hammadi Ali 
Published: November 2015

Abstract
Startup green-field assets go through exponential growth of structured data and unstructured documents and records in core E&P domains. With simultaneous rapid evolution on infrastructure, information security and compliance fronts, this poses considerable challenges in supporting end-user beneficiaries—from real-time drilling operations through to operational improvement and better-informed and auditable decision-making. The data management function needs to be far more adaptive, resilient and agile than its counterpart in matured assets.
This paper describes the Al Hosn Gas journey, over the past few years of existence, down the critical path of E&P data management. Transition from users' local storage to network shared drive-based file management on one hand, and distributed architectures for applications' project data management on the other, constitute important milestones. A hybrid approach to ensuring data availability and optimum throughputs, while complying with fast evolving information security/protection and governance norms, has provided a robust driving mechanism. We discuss the Al Hosn Gas model of integrating "gold" standard data, generated through applications' value chain, to ADNOC’s national data repository.
Challenging though it can be, efficient & effective implementation of data management best practices in a green-field asset environment, as early as possible and as widespread as practical, can result in enormous value addition to end-users & management alike. High degrees of adaptability and resilience of architectures and accompanying processes have enabled Al Hosn Gas to foster a robust and agile data management paradigm.
Production Performance of Horizontal Gas Wells Associated with Non-Darcy Turbulent Flow
Authors: Lu Jing , Li Sima , Rahman Md Motiur 
Published: November 2015

Abstract
In the petroleum literature, non-Darcy flow is assumed to be a near wellbore phenomenon, consequently a gas reservoir could be divided into Darcy’s flow domain and non-Darcy’s flow domain. Assume only radial flow occurs in the near wellbore non-Darcy’s flow domain, and assume the radius of this domain is integer multiple of wellbore radius, Lu et al. (2011) proposed binomial deliverability equations for partially penetrating vertical gas wells and horizontal gas wells. By solving a set of simultaneous equations with respect to non-Darcy’s flow domain rn and flow rate at standard condictions Qsc, this paper presents new binomial deliverability equations for horizontal gas wells, which can account for the advantages of horizontal gas wells where non-darcy effect is less pronounced than that in vertical gas wells. The calculation results show that non-Darcy flow domain radius is smaller than 20 times wellbore radius, which further proves turbulent effect only occurs in the vicinity of wellbore. The calculation results also show that the production rate loss of horizontal wells caused by the turbulent flow is small.