bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometry of Porosity Break Plane Associated with Bitumen Zone and Timing of its Generation in an Upper Jurassic Reservoir, Offshore Abu Dhabi, UAE
Authors: Kojima Haruo , Shibasaki Toshiaki , Inoue Hiroyuki , Al Ameri Mohamed B. 
Published: November 2012

Abstract
An Upper Jurassic reservoir in "Field A" is characterized by existence of bitumen (tar mat) zone intersecting sublayers in the reservoir and porosity deterioration is observed in the bitumen zone and below bitumen zone. It is obvious that porosity deteriorates significantly at top of the bitumen (Porosity Break Plane: PBP) on core materials and open hole log interpretation, in addition, no flow contribution below PBP was confirmed by production logging data due to its tight nature. Therefore, it is very important to define PBP precisely in order to estimate hydrocarbon reserves and optimize future infill well locations.
The thickness of porous interval between top of reservoir and PBP indicates thinning toward the flank area and finally pinching-out in the flank area. The PBP and bitumen have been considered that they were possibly formed near paleo-OWC and the present curved shape of PBP can be attributed structural growth of the field after formation of them by deeper salt swelling.
PBP is confirmed at crest and flank wells in different stratigraphic position depending on their structural locations. Based on the detailed structural interpretation of the top reservoir using recently acquired 3D seismic data, the relationship between the top reservoir depth structure and PBP identified in the wells became clear. It is helpful for the PBP mapping and understanding of the bitumen distribution.
3D geological model incorporating PBP was constructed based on the above observation and new structure map derived from 3D seismic interpretation. This workflow helps to improve predictive capability on PBP mapping in non-well control. In addition, based on the structural interpretation of overburden horizons on the 3D seismic data and newly interpreted PBP, the history of structural development and timing of PBP generation were estimated. Based on the back stripping of overburden formations, PBP seems to be flatten in the Shilaif age. This paper discusses the reasonability of this timing.
Permeability Model Conditioning of a Thin, Heterogeneous High-K Dolomitized Unit in a Supergiant Carbonate Field, Offshore Abu Dhabi
Authors: Yamamoto K. , Kompanik G. , Brantferger K. , Al-Zinati O. , Ottinger G. , Al-Ali A. , Dodge S. , Edwards E. 
Published: November 2012

Abstract
This paper presents a method to condition the permeability modeling of a thin, heterogeneous high-K dolomitized unit. The interval is an important drilling target for field development, so precise permeability modeling is required to optimize well placement and completion designs in order to maximize oil recovery and minimize early water breakthrough.
Detailed core observations from 85 wells classify the unit into two groups: Group A, composed mainly of dolostone and Group B, comprised exclusively of calcareous dolostone. Regression analyses of plug porosity-permeability values are characterized by one regression line for each group by which dolostone represents a higher permeability trend relative to calcareous dolostone. Core-plug scaling is used to scale-up the porosity-permeability relationships from core plug- to modelscale (100 m by 100 m cells). The two regression lines accurately capture the permeability contrast within the dolomitized unit.
To extend the method into a full-field model, it is necessary to calibrate the well logs to the core data. Comparison of cores with various log responses indicates the porosity log is the most useful tool to achieve this. Group A, characterized by higher dolomite content, is distinguished by a distinct decrease in the porosity due to progressive dolomitization.
Porosity logs from 499 wells are interpreted and permeability values are assigned using the regression lines based on the detailed distribution map of both groups. The modeling approach using hundreds of well logs calibrated to cores yields a more detailed picture of the spatial permeability variations of the dolomitized unit. Dynamic data from ongoing history matching is also used to implicitly adjust the first-pass static model.
Application of pressure/fluid sampling measurement for the understanding of the complex fluid movement and communication in a mature, carbonate, heterogeneous reservoir
Authors: Al Mentheri Khawla , Ghalem Salim , Kaouche Salim , Keshtta Osama Mohamed , Al-Mutwali Omar , Shabaan Elbesaily 
Published: November 2012

Abstract
The lower cretaceous Formation reservoirs in Offshore Abu Dhabi represent a regressive cycles of sedimentation developed with shoal, laggonal, subtidal and supratidal sediments. This formation includes various types of lithologies along the reservoir column: Anhydrite alternating with Dolomites, limestone.
In such mature, heterogeneous oil reservoirs with a large gas cap, information may improve cost effective productivity, reduce the risks and improve the oil recovery. Special analysis of pressure measurement, fluid scanning and sampling while drilling is important to challenge open hole log saturation, to understand the behavior of each layer in the reservoir, to assess the communication between the sub layers, and to enhance the development schemes.
This study is a synthesis of all the Open-hole Vertical Pressure Profiling data sush as formation evaluation and sampling that has been performed through the history of the fields.
Investigations have been conducted on the identification of the in-situ reservoir fluid nature; the hydraulic vertical communication between layers; pressure maintenance mechanisms effect and pressure evolution through time and its link with lateral communication.
Furthermore from operational point of view best practices have been developed for a safe and efficient procedure in terms of data acquisition and analysis with the limitations of the formation testing tool.
Challenges and Key Learning for Developing Tight Carbonate Reservoirs
Authors: George Bovan K , Clara Cedric , Al Mazrooei Suhaila , Manseur Saadi , Abdou Medhat , Chong Tee Sin , Al Raeesi Muna 
Published: November 2012

Abstract
Fast track development projects, with timely data acquisition plans for development optimization, are very challenging for tight and heterogeneous carbonate reservoirs. This paper presents the challenges and key learning from initial stages of reservoir development with limited available data. Focus of this study is several stacked carbonate reservoirs in a giant field located in onshore Abu Dhabi. These undeveloped lower cretaceous reservoirs consist of porous sediments inter-bedded with dense layers deposited in a near shore lagoonal environment. The average permeability of these reservoirs is in the range of 0.5-5 md.
Mapping the static properties of these reservoirs is difficult since they are not resolved on seismic due to the low acoustic impedance contrast with adjacent dense layers. Petrophysical evaluation of thin porous bodies inter-bedded with dense layers in highly deviated wells pose significant challenges. Laterolog type LWD resistivity measurements which are less affected by environmental effects, offer more accurate formation resistivity compared to propagation type measurements. With limited suite of logs, some of the zones with complex lithology had to be evaluated innovatively as detailed in the paper. Integrated studies are initiated to improve reservoir description by carrying out accurate permeability mapping, SCAL, geomechanical and diagenesis & rock typing studies.
Significant challenges exist regarding the development of thin, tight and highly heterogeneous reservoirs, in terms of recovery mechanism, well architecture, well count, drilling, well completion and economics. Static and dynamic models were used extensively to evaluate different development scenarios and conduct sensitivity studies to bracket uncertainties. Various geo-steering options were discussed and the paper also details maximizing the reservoir productivity using long reach MRC (Maximum Reservoir Contact) wells.
Tight and heterogeneous reservoirs call for extensive and real time reservoir surveillance activities to assess well performance and reservoir connectivity. This paper highlights how these challenges are overcome through upfront surveillance planning and proactive well completion strategy.
An Integrated Multi-disciplinary Approach to Enhance Confidence in Development of a Tight Heterogeneous Reservoir
Authors: Nakamura Shinichi , AlHabshi Ali , Hussain Ali , Khalil Ashaf , AlBlooshi Jamal 
Published: November 2012

Abstract
This paper covers the integrated approach performed in one of the major oil fields in off-shore Abu Dhabi to increase the confidence level in this tight heterogeneous reservoir development.
This paper outlines the challenges that were faced along with the history of this field and the different approaches made by the development team to overcome them. The paper discusses the steps that the team went through in a period of ten weeks in order to come up in the end with an optimized subsurface & completion strategy plan. It shows how the reservoir with three main reservoir subzones is divided into 43 layers based on the sequence stratigraphy approach. It also discusses how the new infill well locations were optimized and designed with a fit-for-purpose completion strategy.
The paper will present the final outcomes of this review, the opportunities identified and the latest results obtained from the more confident post optimized development plan.
High Precision Monitoring of Crude Oil Storage
Authors: Al Muhairi Mohammed Bin , Al Zaabi Mohammed Abdulla 
Published: November 2012

Summary
High Precision Monitoring of Crude Oil Tanks is very precise and accurate dynamic measurement detecting any Leak during operations. For many decades, the oil industry has been concerned with the financial consequences of oil losses. In recent years, there has also been an increased awareness of the industry's environmental impact. Pollution, caused both by liquid spills and atmospheric emissions, is an area of increased concern, and the industry has initiated programs to reduce the risks of environmental damage. Maintaining an accurate leak detection and reconciliation program is a necessity for anyone environmentally conscious such as a tank farm owner.
This paper describes the innovative solution developed by ZADCO maintenance team for High Precision Monitoring of Crude Oil Tanks system. It also describes the existing Crude Oil storage system hydraulics, technology of level storage tank measurements and control system utilized in developing the High Precision Monitoring logic algorithm. It shows relatively preciseness if the developed solution and the control on the different operations modes and scenarios. The solution became an online dynamic diagnostic and alerts the operators if unpleasant or abnormal operations accur in a time span of 27 seconds.
Safety Culture Study to Improve Safety Performance in Organization
Authors: Aryaguna A. , Argubie B. , Venema W. , Budiman A. , Djunaidi Z. , Kusminanti Y. , Erwandi D. 
Published: November 2012

Abstract
Safety Culture describes the enduring value and priority placed on worker and public safety by everyone in every group at every level of an organization. It is the result of individual and group values, attitudes and beliefs, competencies and patterns of behavior that determine the style and proficiency of the health and safety management in organization.
In recent years, many organizations are showing interest in "Safety Culture" as a means to reduce the high potential incidents, as well as the inherent risks associated with.
TOTAL E&P Indonesie (TEPI) conducted Safety Culture studies based on three main approaches, the Safety Climate Level (SCL), Safety Culture Maturity Level (SCML) and Culture Based Safety (CBS). SCL captures the safety perception within the employees. SCML measures the maturity of the organizational behaviors, which is developed to assist safety improvement processes. The CBS is the model to develop safety norms among workers community through 2 (two) variables: leadership, workers’ empowerment and involvement.
This paper will only focus on the results from the SCML approach that was done in 2005, 2007, and 2010. Based on the studies that was conducted in the mentioned years, the result shows the improvement of Safety Culture values in TEPI and the consistency in accident reduction and control result. The latest study in 2010 shows that TEPI is in the level between 4 and 5, with average score 4.27 (in a scale of 5).
The levels show that TEPI is already in the right track. Rooms for improvements were identified from these studies and action plans are always prepared and implemented in order to have continuous improvement in organization's Safety Culture and performance.
This paper will also analyze the trend analysis between the SCML study results with the safety programs that TEPI has done along the years, safety performances of TEPI, and the Health Safety & Environment Management System (HSE-MS) Implementation.
Integration of Subsurface Data, Modern Analog Concepts, and History Matching Feedback to Model a Thick Carbonate Reservoir, Offshore Abu Dhabi
Authors: Ottinger G. , Kompanik G. , Al Suwaidi M. , Brantferger K. , Edwards H. 
Published: November 2012

Abstract
Sustaining hydrocarbon production to meet growing energy demand is an industry-wide challenge, especially for Middle East projects. Consequently the need for sound, robust models is increasingly important to accurately represent the subsurface ahead of field development/production. A common hurdle to overcome involves scaling core-based geologic characterization to models, such as representing thin high perm streaks or populating facies mosaics. This paper summarizes the approach used to characterize and model a thick carbonate reservoir from a giant offshore Abu Dhabi oil field.
Core descriptions from 36 key wells across the field establish the setting as a structurally modified ramp characterized by patchy facies distributions that was frequently reworked by storms. Core:log calibration was investigated but deemed not applicable for this reservoir, thus core was the primary control on the rock type model. High permeability grainstones and algal/rudist floatstone interpreted as storm deposits are thin (&lt;1 foot) and not correlative between cored wells. The wells were rock typed and mapped to reveal trends between rock types, thickness and reservoir quality.
These trends were integrated with previous learnings and modern analogs to help bridge between the core and model scales, such as for geobody dimensions and spatial variability within the model. Deterministically-guided stochastic distribution of rock types using Truncated Gaussian Simulation was the preferred method to build the rock type model based on data coverage and the vertical stack of facies observed in core. Fine-scale layering in certain zones of the geomodel was necessary to capture the thin high perm streaks. This necessity led to coarser model layers, where applicable, to maintain a manageable geomodel size. Distribution and connectivity of high perm geobodies were guided by multiple feedback iterations from history matched results. These iterations were key to achieve a sound, robust model.
3D Seismic Survey Design Using Point Sources and Point Receivers: A Case Study from the Uae Thrustbelt Region
Authors: van Baaren Peter , May Roger , Zarkhidze Alexander , Morrison David , Quigley John , Al Qadi Abdulla 
Published: November 2012

Abstract Summary
In this paper we describe an integrated design of the acquisition parameters for a 3D seismic survey in a difficult geological and logistical environment using an ultra-high channel count point receiver recording system, productivity enhancement techniques and incorporating advanced processing tools. Advances in acquisition hardware and techniques change the way seismic surveys are designed. These advances include continuous recording, faster computers that allow running more elaborate algorithms, and new methods such as surface wave methods to model and subtract aliased groundroll. These new tools require different input data and different sampling. How these advances influence the design process is illustrated using a case study for a 3D survey acquired in the 3rd quarter of 2011 located in the largely sand covered thrustbelt area of the United Arab Emirates.
The seismic data were acquired using a high productivity technique that uses time and distance rules coupled with integrated QC rules based on active spread criteria to maximize productivity and minimize cross-talk between the individual seismic sources. The initial data from the 3D survey shows that the proposed integrated 3D survey design is adequate for coherent noise attenuation, source cross-talk removal and building a near-surface model.
Alkali Surfactant Gas Injection: Attractive Laboratory Results Under the Harsh Salinity and Temperature Conditions of Middle East Carbonates
Authors: Cottin C. , Morel D. , Levitt D. , Cordelier P. , Pope G. 
Published: November 2012

Abstract
Alkali-surfactant-polymer (ASP) injection is an attractive enhanced oil recovery (EOR) technique that allows achieving almost zero residual oil saturation at the microscopic scale when well designed. In this combination of chemicals, the role of polymer is to achieve the necessary mobility control of the microemulsion / oil fronts which are formed and propagated through the reservoir. Foam has been recently identified as an alternative to polymer to achieve such mobility control.
This paper describes the alkali-surfactant-gas (ASG) and surfactant-gas (SG) laboratory results which have been obtained on carbonate core samples under harsh salinity (~230 g/L) and temperature (83°C) conditions representative of some Middle East reservoirs.
The starting point was the development of a surfactant formulation to achieve ultra-low interfacial tension between the oil and injected solution in these particular salinity and temperature conditions, using the classical microemulsion phase behavior approach. This formulation used a class of surfactants newly developed at The University of Texas at Austin (UTA), compatible with and without divalent ions.
The efficiency (in terms of oil recovery) of this chemical formulation was demonstrated with SP core floods. The same chemical formulation was used for SG as the starting point, and was further enhanced; the polymer was replaced by nitrogen or methane co-injected with surfactant to create foam.
Extensive studies of the ASG process have been performed. This includes phase behavior with and without alkali, screening laboratory studies to pre-select the surfactant with adequate foam properties, and carbonate coreflood experiments to measure the residual oil saturation to SG injection, including the consumption of chemicals. There is still room for optimization, but very promising results have already been obtained on that particular case leading to high recovery of the remaining oil after waterflood.
Application of Advanced Analysis Techniques for Waterflood Management: A Case Study in a Large Heterogeneous Carbonate Reservoir
Authors: Al Henshiri M. Yousef , Tariq Syed 
Published: November 2012

Abstract
Literature is replete with numerous techniques for waterflood analysis developed over the last four decades. Most of these techniques are in the form of simple diagnostic plots based on available production/injection and pressure data routinely gathered in the field.
This paper illustrates a systematic methodology that integrates various diagnostic plots at field, sector, pattern and well levels. It shows the interaction between these levels and how the integration of different diagnostic techniques are key to better understand the dynamics of waterflood performance and for identification of performance improvement opportunities. The techniques presented in this paper were applied to evaluate the waterflood performance & efficiency, to identify anomalous performances, to detect production and injection problems, to establish water production mechanism, and to assess impact of reservoir heterogeneities in a giant carbonate reservoir located in the Arabian Gulf. The subject reservoir has been producing under a large scale pattern waterflood for over 30 years.
The construction and uses of various diagnostic plots for quantitative assessment of the waterflood performance are presented in this paper. As a first step, the historical performance plots are used to evaluate the maturity of water production and to provide an indication of the sweep and recovery efficiency. The voidage replacement ratio (VRR) when integrated with historical pressure profiles and material balance plots provides critical information on the reservoir pressurization process. The water breakthrough time and the WOR trends are then used in evaluating the water production mechanism and in assessing the reservoir heterogeneity. Production logs (PLT, WFL, PNC, CHFR and RST) provide key information for monitoring and evaluating vertical and areal sweep in the reservoir. Hall plots provide information regarding the injection well performance and related dynamics.
The approach presented above led to significant enhancement in understanding the displacement process and water movement within the reservoir. The integrated analysis resulted in improvements in the field practices for reservoir management and well completion design for future development wells.
Extended Reach Horizontal Accessibility for UAE Offshore
Authors: Issa Faiz , Jackson Alfred , Hudson Lisa 
Published: November 2012

Abstract
The UAE field has many thin multilayered carbonate reservoirs. Production from thse thin reservoirs are primarily supported by water injection. Reservoir properties, such as permeability, pore pressure, and water saturation, vary significantly both across the field geographically and within the different layers.
Recently a study has been done to drill and maximize reservoir contact via ERD wells. To reduce costs and improve recovery, further development of the plan is to use wells drilled with throws greater than 15,000 ft and measured depths greater than 20,000 ft with some wells exceeding 35,000 ft. Long horizontals provide many benefits including enhanced access to offshore reserves, optimized productivity, reduced capital expenditure, and a minimized environmental impact
With these benefits come challenges, accessibility for intervention operations being the most prevalent. Many factors affect the accessibility and intervention capabilities in ERD wells. Completion ID restrictions play a critical role in the equipment availability and selection. Once equipment is selected the leading principles used for improved access in ERD applications are:
Increasing pipe bending stiffness to postpone helical buckling Reducing Normal Force between the CT wellbore Reducing Friction Coefficient Adding Axial Forces
ERD applications and accessibility for interventions have been an ongoing challenge on how to properly model and predict the reach of CT in varying environments. The two pilot wells covered in this paper allowed for an array of information to be collected as the trajectories were very similar but the wells themselves were very unique. One well was a producer while the other was an injector. One well was completed with 13% Chromium and the other with conventional tubing.
In this paper we will cover the above topics in more detail to clearly outline the challenges of ERD operations and the methods to overcome them. It will be clearly outline how these methods were used on two ERD pilot wells in UAE with the supporting actual operational data. These wells and lessons learned will pave the way for future ERD operations planned in both offshore and island based offshore UAE pilot projects.