bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated Characterization of UAE Outcrops: From Rocks to Fluid Flow Simulation
Authors: Vaughan R. L. , Khan S. A. , Weber L. J. , Suwaina O. , Al-Mansoori A. , Ghani A. , Strohmenger C. J. , Herrmann M. A. , Hulstrand D. 
Published: December 2007

Abstract
This paper describes a systematic and logical workflow for characterizing a UAE outcrop of the Upper Thamama reservoir. This integrated workflow uses sequence stratigraphy, geologic modeling, and fluid flow simulation and was used as a tool for training early-career UAE geoscientists and engineers. Although the primary focus of the paper is on the mechanics of geologic modeling with principles applicable to UAE fields, the integrated workflow covers the entire spectrum from rock characterization all the way to flow simulation.
Outcrop analogs are a valuable source of data for reservoir characterization. They are particularly useful for visualizing interwell variability because subsurface wellbores represent discrete widely spaced data. In other words, outcrops provide the continuous, large-scale coverage of a seismic line and provide the fine-scale resolution of core measurements. Modeling input parameters such as lateral and vertical continuity (variogram range), object dimensions (aspect ratios), detailed reservoir architecture (layering), facies relationships, and the nature and extent of diagenetic features can be observed and measured.
To better understand reservoir properties of the Upper Thamama producing zones in Abu Dhabi, a geologic model was developed from descriptions of time-equivalent, analogous outcrops in the Emirate of Ras Al-Khaimah. Parasequences, maximum flooding surfaces, sequence boundaries and lithofacies were described in four measured sections. Porosity measurements derived from logs, core porosity, and core permeability data from an Abu Dhabi oil field were applied to similar lithofacies observed in outcrop. These subsurface data were used in the outcrop 3D model to more precisely reflect subsurface reservoir behavior because outcrops in the UAE experienced a significantly different burial history relative to the subsurface reservoirs.1
For the stratigraphic interval studied in outcrop (i.e., Upper and Lower Kharaib Formation), four composite reservoir facies (three permeable and one "dense") adequately described the flow behavior. These reservoir facies were modeled using Petrel2 software and were scaled up into a simulation model using ExxonMobil's next generation reservoir simulator, EMpower.™,3 Multiple scenarios, including various injection patterns, scaleup methods, and locations of thin, high-permeability streaks, were investigated. Results mimicked known behavior in analogous producing fields and the process of going from rock data to simulation provided a useful training tool for reservoir characterization methods and techniques.
Expandable Tubular Completions for Carbonate Reservoirs
Authors: Marketz F. , van Noort R. H. J. , Baaijens M. N. 
Published: December 2007

Abstract
Expandable tubular solutions have been developed and applied as a drilling solution to extend well depth while maintaining a larger borehole diameter [1]. In this paper we review the benefits of expandable tubulars for shut-off and zonal isolation in carbonate reservoirs. Particular emphasis is given on a major Middle East Operator's experience.
Expandable open hole liner (OHL) systems, developed as a drilling solution, is based on expanding a liner across an open hole section and into the previous casing to form a liner hanger [2]. Instead of cement, elastomer seals provide zonal isolation in open hole [3], [4]. The liner is expanded to create a seal by energizing an elastomer between casing and the formation. In addition the elastomer swells in contact with water. This dual sealing mechanism provides an annular seal of any desired length. The technology is non-invasive on the reservoir. Alternative technologies either are invasive on the reservoir or have had limited success, i.e. cement, chemical squeezes or scab liners.
Expandable tubular solutions have proven successful in terms of installation reliability, isolation of fractures, swept zones and ghost holes. Also, the technology enabled inflow profile control through zonal isolation in horizontal wells. Case histories for shut-off and zonal isolation demonstrate the viability of extending the scope of expandable technology deployment for better management of carbonate reservoirs through a "drill, monitor & intervene" completion philosophy combining selectivity and shut-off in a low-cost intelligent completion solution.
A Turbine Flow Meter for Multiphase Flow
Authors: Li Zh.Y. , Kitami H. , Kawaoto H. , Watanabe T. 
Published: December 2007

Abstract
This paper introduces a new concept and the test result of a multiphase flow meter (MPFM), which JOGMEC (Old JNOC) and OVAL Corporation have developed based on a turbine type flow meter to measure the multiphase flow rate of individual phases in oil, water and gas production lines without the need for separation or complex sensor technologies (1)(2).
It is expected that the MPFM should bring a significant cost-down and improved operability and maintainability, compared with commercially available the turbine type MPFM in terms of nuclear-absorption type density measuring.
We had adopted integral calculus method and established a mathematics model.
In addition, we have examined the characteristics of the MPFM using a number of liquids with different viscosities (1–20mPa.s).
The test result shows that the volumetric flow rate of each phase are possibly measured with an uncertainty within ±10% of full range of the water cut and the gas void fraction varies from 30 to 90%. To confirm the MPFM reliability, MPFM monitoring was done for one year in an oil reservoir with water flooding in the wellhead platforms in Middle East. The MPFM measurement system can obtain enough accuracy to measure flow rates in each phase.
Evaluation of Coriolis Meters and Gas Flow Computers for Well Testing
Authors: Al-Saqabi Mishari , Kahali Kishore , Al-Kandari Ibrahim M. 
Published: December 2007

Abstract
Accurate and timely welltest data is critical to evaluate well performance and for effective reservoir management. In Kuwait Oil Company's Burgan South and East areas, the standard method of welltesting in the past has been through test separators and test tank. Because of the flow rate stabilization time and minimum volume required in the test tank for accurate reading of fluid level, welltest duration can range from 10 to 24 hours, especially for low volume wells. This is an operational challenge from the standpoint of acquiring accurate data and meet welltest frequency targets.
In an effort to meet these goals, KOC has installed a new system of well testing with Coriolis meter and AGA Gas flow meters in its gathering centers (GCs). The coriolis meter, an online mass and density flow meter, can measure well flow rates with reasonable accuracy within 1–2 hours.
This study has compared "simultaneous" well tests results of different categories of wells – high and low flow rate, dry and wet and high GOR using the Coriolis meter, GC test tank and portable test separator at the well. The performance and accuracy of this technology of well testing under different flow conditions are reported.
Sour Gas Development – Technical and Operational Integrity Issues and Management
Authors: Kamath A. R. Ramachandra , Milligan Michael , Dorp Johan van , Morsi Kamal , Szklarz Karol , Rippon Ian 
Published: December 2007

Abstract
Technical & operational integrity issues and their resolutions are dealt with leading to the concept selection for a high H2S (33% H2S) gas development in Abu Dhabi. Two strategic principles underpinned the concept selection and field development plan: (1) minimise Health, Safety and Environment (HSE) risks and (2) employ field proven technology and practices as far as practicable. Sulphur production instead of acid gas injection was rejected as a viable development option due to its environmental impact and the poor prospects for sulphur marketing. Developmental technical issues included sulphur precipitation in the production tubing and pipelines, and material selection for the sour gas well completions and the gathering & injection pipelines. Materials selection was based on designing out all catastrophic failures and corrosion mitigation & monitoring of progressive corrosion failure mechanisms. Operational issues were related to minimal facility manning and competence assurance of sour gas operatives.
New Analytical Solutions for 1-D Multicomponent Gas Injection Problems
Authors: Bedrikovetsky P. G. , Shapiro A. A. , Pires A. P. 
Published: December 2007

Abstract
Analytical models for 1-D displacement of oil by gas have been developed during the last 15 years. It was observed from semi-analytical and numerical experiments that several thermodynamic features of the process (MMP, key tie lines, etc) are not dependent on transport properties. After change of independent variables, the compositional (n-1)*(n-1) model for n-component flow is divided into a thermodynamics auxiliary (n-2)*(n-2) system and one transport equation. Explicit projection and lifting procedures are derived. The new technique developed permits splitting for both self-similar continuous injection problems and for non-self-similar slug injection problems. New different solutions for non-self-similar problems of gas injection in oil reservoirs are presented. With respect to 3-D flows, splitting takes place only for the case of constant total mobility (where the stream line concept is valid). For the general case of the total mobility variation, mixing between fluids that enter different streamlines occurs, and splitting does not happen any more.
Techniques to Aid Rapid Detection of High Permeability Conduits and Barriers in Reservoirs
Authors: Carnegie Andrew 
Published: December 2007

Abstract
Techniques based upon proportion curves and event analysis can greatly aid rapid detection of possible high permeability conduits and/or barriers in reservoirs. The techniques can use both dynamic data such as production rates and monitoring logs as well as static data such as open hole well logs. A recently created interactive PC software package allows effective application of these techniques. An example is presented of how the techniques greatly accelerated the history match of a heterogeneous carbonate reservoir by improving the calibration of open hole permeability log predictors by dynamic data, and allowing the conduit and barrier structure to be largely understood before full field history matching stage.
Suggestions are made on when and how to generally apply these techniques. It will be suggested that such techniques can supply inputs for distribution methods, such as Indicator Kriging and Truncated Gaussian Simulation, and thereby significantly enhance them. Other unconventional, yet useful applications of proportion curves will be mentioned, such as monitoring the changes being made in large flow simulation models during history matching, and determining areas where further data acquisition might be useful.
Correlation of the Upper Dalan/Kangan Formation between offshore Iran and the Zagros: Impact of lateral changes in facies and diagenesis on reservoir quality
Authors: INSALACO Enzo , LESCANNE Marc , MASSE Pierre , WALGENWITZ Fredéric , SUDRIE Marina , THIRY-BASTIEN Philippe , ROUMAGNAC Alain , FRAISSE Christian , KAMALI Mohammad , MOALLEMI Ali , LOTFPOUR Masoud , MONIBI Saeed , GAILLOT Jérémie 
Published: December 2007

Abstract
The Dalan/Kangan (Khuff) Formation is a major reservoir in Iran and the rest of the Middle East Gulf region, and contains some of the world's biggest gas reserves. The reservoir facies of this formation developed on a very large regional carbonate platform which had a very low topographic relief. This large geographic extent of the platform system is responsible for the development of very extensive facies tracts - in order to encounter major facies changes, large areas need to be investigated. This is often not possible in detailed reservoir-scale studies. In such cases, integrated models that extend from proximal positions to more oceanward locations are difficult to apply.
In order to address these issues a large multidisciplinary and multiscale subsurface study has been launched on a large database including fields from onshore and offshore Iran. The aims to better understand the facies distributions, sequence stratigraphic architecture and the regional reservoir development.
Twenty-two principal facies have been recognized including massive to laminated anhydrite, mudstone with anhydritic nodules, dolobreccias, green shale, massive to bioturbated mudstone, laminated dolomudstone, coarse lithoclastic and bioclastic grainstone, bioclastic grainstones, oolitic grainstones, peloidal grainstones, dark mudstones, and thrombolitic limestone. These facies have been interpreted in terms of depositional environment including: evaporitic flats or saltern (shelf supratidal/intertidal to subtidal setting), tidal flats (intertidal to supratidal setting, with numerous subenvironments such beach ridges, intertidal flats, tidal channels), subtidal lagoon (subtidal setting), leeward shoals (subtidal to intertidal setting), oolitic to oobioclastic shoal belts (subtidal to intertidal setting), composite sandwave constructions (subtidal setting), and middle shelf deposits (subtidal setting).
From the Dalan K4 through to the Kangan K1 significant changes in platform type/geometry, facies organization and climate occurred. Consequently, different depositional models need to be created for each of the major stratigraphic interval. Conceptual geological models have been constructed for the large-scale stratigraphic architecture, sedimentological organization and the palaeoecological systems. The correlations show significant changes in sedimentological and reservoir facies across the study area, which are not evident at smaller scales. These large-scale geographic and stratigraphic facies trends provide a regional framework which can then be used to help constrain reservoir-scale studies.
Historical Review and Rock Mechanics Approach to Improve the Wellbore Stability in Nahr Umr Shale Formation
Authors: Yamamoto K. , Waragai T. , Kikuchi S. , Fada'q A. S. , Koyama T. , Matsunaga T. 
Published: December 2007

Abstract
In this paper, the historical review for the drilling troubles encountered in the Nahr Umr (N.Umr) shale formation and the rock mechanics approach to improve the wellbore stability are described. An integrated approach is adopted for this study including the historical review for the actual drilling practices implemented to date, the studies of geomechanics, rock mechanics and chemistry for the N. Umr shale formation.
The historical review is performed based on the actual drilling data from year 1991 to March 2004.
The geomechanics model is determined with the data from the N. Umr shale formation and adjacent reservoirs. Logging data and collected formation sample data i.e. cores, cuttings are utilized to measure the properties of the formation. Numerical models considering the anisotropy and poroelastic nature of the shale lead the quantification of the failure mechanism.
Laboratory testings are conducted to analyze the basic chemical properties of the shale, and the interaction between the shale and mud. A newly produced testing apparatus is applied to determine the shear strength change of the shale under saturated condition with mud. Scanning Electron Microscope is utilized to ensure the failure mechanism and evaluate the validity of the shale inhibitors.
In this paper, the outline of the approaches is shown with some details of the testing and analysis methods.
4D Feasibility and Calibration Using 3D Seismic Modeling of Reservoir Models
Authors: Toinet Sylvain 
Published: December 2007

Abstract
Monitoring fluid motions in a producing reservoir is a key to understand reservoir behavior and anticipate drilling decisions and investments. In a deep-water environment such as Girassol (Angolan deep water, West Africa), the cost of a 4D seismic is less than the cost of a well, and 4D seismic is expected to provide the necessary monitoring information in terms of saturation and movement of fluids. Meanwhile, before deciding to repeat a 3D acquisition, the main question to answer through a feasibility study is: will the dynamic changes occurring in the reservoir be visible on seismic data? To achieve the 4D feasibility study, a reservoir model representing the state of the reservoir before production/injection, and another reservoir model after a certain time of production/injection were built. 3D Pre-stack synthetic seismic responses of the models were then computed in time and in depth using a fast algorithm accounting for fine-scale details of the reservoir model. Average amplitude maps extracted at key horizons, from the difference between 3D synthetic seismic responses of the two reservoir models showed the anticipated lateral extent of injection and production, and the impact in terms of amplitudes of the different injection and production mechanisms. These results of the 4D feasibility made us confident in the fact that the forecasted 3D seismic acquisition would provide important information about the reservoir dynamic characteristics. Since this work has been conducted, the new 3D seismic data that have been acquired. The identification and understanding of the differences between real and synthetic data helped us qualitatively and quantitatively to update the reservoir model and the petro-elastic model.
Porosity Heterogeneity Analysis Using Geostatistics
Authors: Gyllensten A. , Tilke P. , Al-Raisi M. , Allen D. 
Published: December 2007

Abstract
High levels of heterogeneity in many carbonate fields have raised concerns about the validity and relevance of small-scale measurements from core plugs and high-resolution logs. Although the measurements may be precise, they may not accurately describe average formation properties. A related question is one of reconciling the variability observed in small volume-of-investigation data (e.g., core plug), with the variability in relatively large volume-of-investigation measurements (e.g., wireline logs).
In a recent study of early Cretaceous carbonate reservoirs in Abu Dhabi, we developed a technique to address this issue using high-resolution borehole imaging logs. The resistivity image is first transformed into a porosity image using Archie's equation. The resulting porosity variability is then analyzed using geostatistics. This analysis allows us to extract geostatistical parameters (range and sill) at the scale of the borehole image measurements (0.1 in.) that provide a heterogeneity index for the rock.
We found that the scale of the heterogeneity is sufficiently small (typically less than 1 in.), such that significant heterogeneity will be observed at the core plug and smaller scales of measurement, while the impact on larger-volume logging tool response is minimal.
The fact that standard wireline logs are insensitive to most of the "heterogeneity" in these formations explains the difficulties in determining reservoir rock types (RRTs) from standard logs, because the properties distinguishing the RRTs from one another (macrofossils and molds) are present at a scale below the sensitivity of standard logs. In contrast, properties measured by the logs can be expected to reflect the larger-scale reservoir properties around the well.
These findings have significant impact on how we calibrate logs using core data and how we should upscale reservoir properties derived from core and log data in our 3D earth models.
The findings support our recommendation to use core plugs larger than the conventional 1-in. plugs in carbonate formations to ensure that the small-scale heterogeneities are captured within the core plug itself.
Four-Phase Streamline-Based Compositional Simulation of Gas Injections for a Viscous Oil
Authors: Li Dacun 
Published: December 2007

Abstract
Because it is extremely time-consuming to run compositional simulations, people tend to use fewer components, or fewer grid blocks, or both. However, the use of fewer components leads to inaccurate phase behavior while application of fewer grid blocks causes larger numerical dispersions. When the reservoir temperature is lower than 120 °F and pressure is lower than 1500 psia, gas injections, especially when injectants include CO2, may result in four phases: water, oil, gas, and the second non-aqueous liquid. In this paper, a streamline simulator is developed and found to be able to be used to model the four-phase flow for the 9-component injection of 50-50 combination of Prudhoe Bay Gas (PBG) and Natural Gas Liquid (LNG) into a reservoir with 12-component viscous Shrader oil. Results indicate that the streamline simulation is many times faster than finite-difference simulation. In addition, viscous fingering is sharply caught by streamline simulation while the displacement front is very blurry in finite-difference simulation due to high numerical dispersions.
The streamline simulator can be used for gas injection problems with up to four phases.
The Upper Khuff formation, sedimentology and Static Core Rock Type approach - Comparison of two offshore Abu Dhabi fields
Authors: Meyer A. , Boichard R. , Azzam I. , Al-Amoudi A. 
Published: December 2007

Abstract
A study focused on the sedimentology framework and on the Static Core Rock Type determination has been carried out on the Permo-Triassic upper Khuff reservoir formation in order to improve the full field reservoir models of two Abu Dhabi Offshore gas fields.
The comparison of results indicates that the Khuff formation can be described by twelve lithofacies corresponding to five main depositional environments ranging from sabkha to oo-bioclastic shoal. The sequence stratigraphy evolution of these depositional environments leads to establish a fine scale reservoir layering, which evidences a large extent of the defined lithofacies between the two investigated fields. The limit between the Permian and Triassic series has also been defined. The results obtained from the sedimentary setting between these two fields provide important keys for further sedimentological and reservoir layering studies regarding other Abu Dhabi fields.
Eighteen Static Core Rock Types have been defined by combining lithology, lithofacies, pore type association and petrophysical properties (K, PHI, MICP). If three major Core Rock Type groups can be easily differentiated (Limestone, Fabric-Selective and Non Fabric Selective Dolomite), some differences related to the diagenesis intensity, especially the dolomitisation process and the late anhydrite precipitation, exist between the two fields. Consequently, the lateral extent of the Core Rock Types can be very variable within a defined reservoir layer. Mapping the Rock type variations requires both, full analysis and integration of all sedimentological, diagenetic and petro-physical data in order to better constrain a 3D full field model.