bluuebunny/crossref_metadata_2025_split huggingface dataset:
Successful Recovery and Stimulation of a Long HP/HT Horizontal Well in One Intervention: A Case History of Acid Fracturing and New Generation of Diversion Systems Combination, Middle Marrat Carbonate Formation
Authors: Sierra Leopoldo , Alboueshi Alaa Eldine , Elmofti Mohamed , Eid Walid , Sadeddin Salma , Allam Ahmed , Al Othman Mohamed , Ahmed Zamzam , Fidan Erkan , Al-Zaidani Ibrahim , Nilotpaul Neoq , Ashkanani Meshari , Buhamad Ali , Al-Dousari Mohammed Abdullah , Ahmed Abdul-Samad Mohammed , Al-Matrouk Yousef 
Published: November 2017

Abstract
The proper fracture stimulation of high-pressure/high-temperature (HP/HT) carbonate formations completed with horizontal wellbores is a challenging task for any operator or service company, particularly because of concerns associated with HP/HT, acid reactivity, completion and production equipment corrosion, and acid distribution. The case history presented in this paper describes the performance of an acid fracture intervention in a HP/HT well where, because of a number of problems encountered during the well construction stage, this intervention was the last procedure considered to evaluate the productivity of a Marrat formation well.
In view of the stimulation challenges encountered, the architecture of the wellbore, and the intervention stimulation requirement to evaluate the productivity of the horizontal well completed in the Marrat formation, it was necessary to change the proppant fracture stimulation technique originally planned. Instead, it was decided that a selective acid fracture stimulation would be performed in the prospective part of the horizontal section where three long perforation clusters had been placed. Acidizing fracture stimulation was performed in one intervention using a next-generation liquid and soluble solid diversion system that enabled the generation of one selective fracture per perforation cluster.
The planned acidizing fracture stimulation process was implemented properly in the field in accordance with the design constraints. The reactive fluid system diversion and the generation of a new fracture when the diversion system reached the perforation were clearly observed. The post-acid fractured well productivity index (PI) showed the high quality of the stimulation performed in a challenging environment, demonstrating the effectiveness of the new diversion system for creating selective fractures in a horizontal wellbore with multiple perforation clusters.
Considering the well's architecture, HP/HT nature, and single intervention requirement, the case study documented in the paper can be helpful in the decision-making process when selecting a proper stimulation technique for challenging conditions. The effectiveness of the new diversion systems is also discussed.
Selection of Optimized Gas Processing and Sulphur Recovery Technology Line Ups for Different Feed Gases
Authors: Srinivasan Rajiv , Sonawane Nilesh 
Published: November 2017

Abstract
Petroleum Development Oman (PDO) is developing sour gas fields across the country in order to meet the gas demand to sustain industrial growth in Sultanate of Oman.
The projects involve development of high pressure, high temperature sour associated gas reservoirs with oil rims as well as non-associated gas reservoirs. The reservoirs are located at a depth of around 3 - 5 km. The sour gas produced contain significant amounts of H2S and CO2 in addition to other contaminants such as mercaptans, carbonyl sulphide (COS) and carbon disulphide (CS2).
For a couple of projects, in the absence of a suitable sink for the acid gas and due to HSE risks associated with high pressure acid gas injection (&gt; 400 bar), sulphur recovery has been selected as the acid gas processing route. The various sour gas fields being developed have different levels of contaminants whereby employing a standardized process line up of gas treatment and sulphur recovery technologies may not be either technically feasible or economically optimum.
Among the many engineering challenges associated with any sour gas field development, the combination of Sultanate of Oman's ultra-high sulphur-recovery efficiency (SRE) specification of 99.9%, and the very stringent SO2 emission specification of 35 mg/Nm3, poses a steep challenge and pushes established technological boundaries. Further, if the sweet gas produced will have to be exported to the Government Gas network, it has to meet a tight total sulphur specification of &lt; 5 ppmv. In case the gas is to be used for internal consumption within PDO, the total sulphur specification is &lt; 100 ppmv.
The combination of these regulatory requirements makes the design of the gas treatment and sulphur recovery facilities extremely challenging. It is clear that best-in-class solutions would be necessary for the projects to comply with the standards.
The concentration of different contaminants in the feed gas and the selection of the sweet gas export route dictate the choice of optimum gas processing and sulphur recovery technologies and their integration. For the projects under consideration, PDO has evaluated a wide portfolio of gas processing and sulphur recovery technologies and has selected process line ups comprising of a fit for purpose combination of technologies.
An integrated approach ensured that interfaces between the different units were efficiently managed and the configuration was fully optimized thereby enhancing energy efficiency.
This paper presents the selection of the optimized combination of gas processing and sulphur recovery technologies that cater for different feed gas contaminant concentrations and yet comply with the regulatory requirements.
Key Learnings from Re-Development Activity and Waterflood EOR of Mature Brown Field: Heterogeneous Compartmentalized Reservoir Case Study, Western Desert, Egypt
Authors: El-Bagoury M. A. , Fahmy M. , Kamal M. , Saad A. , VanHeeswijk V. , Kharboutly R. 
Published: November 2017

Abstract
In this research an integrated reservoir study was performed on one of the successful water flood projects in Bapetco; The NE-Abu Gharadig-1 field which passes through a several phases of development started with appraisal and delineation, initial development (fast track), re-development phase and last phase of reservoir simulation. The conducted field re-development activities increase the EOR expectations and tackle the remaining reservoir potential.
Until the moment 58 wells were drilled in this field 29 oil producer, 26 water injector and 3 water source wells. Different accumulations and segments were interpreted; these segments did not indicate full communication as the thinly bedded Bahariya sequence of 200 meter thickness shows a wide range of reservoir properties and heterogeneity including porosity, permeability and hydrocarbon saturation. Geo-cellar modeling approach was beneficial in this field in order to link the static and dynamic data until reaching a certain level of match and harmony.
Twelve productive zones were interrelated through an attempt to construct structural and stratigraphic facies distribution framework guided by cores and BHI. The 3D geo-cellar modeling was applied to the probable cases and prospective blocks. Petrel data analysis tool was activated in order to control the probability distribution in property modeling. Further reservoir simulator was used to incorporate the engineering data as pressure and production; therefore optimal development strategies are aligned with the findings and forecasts of each reservoir sector. The results indicate a massive variation in vertical and lateral OIIP distribution and URF which is ranging from 16 % to 40 % on the best chances; this variance controlled by the reservoir architecture, compartmentalization, reservoir rock types, relative permeability curves, minor faults and fractures associated with different stress regimes.
The WF pattern fitting and placement were optimized to overcome the geological constrains by additional two phases of infill wells. The results provides a robust reserves stair case through a multi-phases of development and modeling to increase the field production life, improve pattern flood, optimize enhanced recovery and smooth operation.
A New Shortcut Workflow in Flexible Reservoir Modeling: Introducing Structural Features without Re-Gridding
Authors: Martínez Alejandro Rodríguez , Frambati Stefano 
Published: November 2017

Abstract
Current reservoir modeling workflows are very rigid, since any modification to the understanding of the underlying structural model often requires a complete regeneration of the reservoir grid, with the associated costs, delays and incompatibilities with past calculations. We propose a novel workflow for structural features modeling, allowing the introduction of faults and other structural and non-structural features in any kind of simulation grid without modifying it. A new tool, capable of implementing the proposed workflow, is presented along with several real-world case studies that prove the advantages of the new workflow.
Workflow For Multi-Scale Data Integration in Onshore CO2 EOR Project
Authors: Igarashi Akira , Shimokata Noriaki 
Published: November 2017

Abstract
The planning stage of CO2 EOR evaluation of remaining oil volume including immovable oil is one of the most important work because of its significant impact on field performance and project economics. However, planning becomes very challenging when the concerned field is a legacy field where historical data are insufficient unless reliable data were later supplemented. This paper describes how to evaluate CO2 EOR project for a legacy field with insufficient historical data.
To estimate the remaining movable/immovable oil volume in the field, the following multi-scale data were reviewed. Varying results were captured by review as shown below; SCAL (Special Core AnaLysis) ReviewSWCTT (Single Well Chemical Tracer Test)Material Balance CalculationCO2 Pilot Test
Residual oil saturation measured in-situ by SWCTT in wellbore scale was cross-checked with past SCAL results in core scale. Remaining oil saturation was estimated by utilizing a full-field reservoir model with material balance check. CO2 Pilot Test confirmed oil saturation decrease after CO2 injection in well-logging scale. As a result, uncertainties were identified in the residual and remaining oil saturation.
A Type Curve that represents production performance of a certain area/zone was established based on numerical pattern model incorporating reservoir characteristics including the above oil saturation profiles. By superposing the Type Curves as per the pattern development schedule, total field production profile was predicted. Incorporating the above uncertainties of residual/remaining oil saturations, several Type Curves were prepared.
Additionally, a reservoir simulation study indicates that the WAG scheme, for instances WAG ratio and slug size, would impact on an incremental oil recovery. Accordingly, an optimization study of the WAG scheme is currently in progress and this will impact on oil recovery.
In summary, oil recovery estimate for this particular legacy oil field required detailed data reviews mainly due to uncertainties of the volume of remaining oil. CO2 Pilot Test results provided direct evaluation of EOR effectiveness and supported oil saturation change with CO2 injection. Residual/remaining oil saturation need to be revisited with the additional information acquired during project execution stage to improve the accuracy of estimated incremental oil recovery.
Integrated Formation Evaluation Applications in Tarmat Identification, Well Placement, and ICD Completions Design Using Source-Less NMR Technology – A Case Study from a Middle East Jurassic Reservoir
Authors: Anurag Atul , Mishra Anoop , Mustafa Hammad , Hosany Khalil Ibrahim , AL-Jefri Ghassan M. , Chitre Sunil , Javid Khalid , Smart Charles , Bhatt Pranjal , Soliman Ahmed , Kieduppatum Piyanuch , Potshangbam Sanathoi 
Published: November 2017

Abstract
This paper presents the successful integration of an advanced nuclear magnetic resonance (NMR) log, a source-less technology, with core data and other openhole logs to resolve the challenges of reservoir characterization (including identification of tar mat) and to place the wells in targeted reservoirs zones. This enabled subsequent inflow control devices (ICD) completion design for optimal production in these complex carbonate Jurassic reservoirs.
A comprehensive suite of advanced logs, conventional logs and core data were used. The wireline suite covered conventional (resistivity-density-neutron-gamma ray-acoustic) and advanced (NMR-elemental spectroscopy-image) technologies in one of the pilot wells. In another calibration well, data gathering was achieved with wireline (resistivity-density-neutron-gamma ray) and LWD NMR to log the same reservoirs. Integration using these conventional logs, advanced logs and core data established the correlations to derive permeability in this complex carbonate Jurassic reservoirs. From these study wells, a correlation was established between the NMR porosity, density/neutron porosity and core porosity to enhance confidence on NMR-measured porosity. The NMR permeability index was calibrated using parameters that were developed by integrating NMR results with the core data. This permeability relationship (core and NMR) was applied in all lateral wells with LWD NMR results that targeted the same reservoirs in the field. For delineating the tar mat interval, a combination of NMR, density and resistivity measurements was used.
The LWD NMR results provided real-time reservoir characterization with rock quality (porosity distribution, permeability) that helped in ICD completion design and enhanced well placement. This approach and technology also enabled substantial rig time savings and reduced HSE risks.
This approach demonstrates strong benefits of data integration and proven LWD NMR source-less and lithology-independent technology, in addition to the resistivity and gamma ray, as the preferred solution for advanced reservoir characterization, ICD completion design, and enhanced well placement in complex carbonate reservoirs.
The solution for reservoir characterization enabled confident decisions on ICD completion design and enhanced well placement by implementation of source-less technology, eliminating the risks of using radioactive source-based technology.
Saturation Modelling Under Complex Fluid Fill History - Drainage and Imbibition
Authors: Xian H. , Beugelsdijk L. , Kohli A. , Fokkema E. , Cense A. 
Published: November 2017

Abstract
A saturation modelling approach is presented for fields and reservoirs under complex hydrocarbon charging history. The model resolves saturation-height functions for the primary drainage, imbibition and secondary drainage equilibriums. As part of the approach, a method of evaluating the residual hydrocarbon saturation below the initial free water level is proposed.
The developed theory is based on the principle of capillary pressure-saturation hysteresis on the drainage-imbibition process in a water wet system. In this study, saturation-height models have been built with parameters determined by fitting the SCAL capillary pressure drainage and imbibition measurements. A novel approach is presented for evaluating the residual hydrocarbon saturation in relationship with the initial hydrocarbon saturation, integrating both core measurements and log saturation with a pressure depletion factor. An integrated process of modelling a primary drainage-imbibition-secondary drainage cycle based on both SCAL data and well logs is provided.
Parameters for the primary drainage, imbibition and secondary drainage curves are resolved respectively. Large variety of SCAL capillary pressure data and well logs from The Netherlands and North Sea fields are used in the study. The modified van Genuchten (VG) equation provides the best fit with the core imbibition curves and has subsequently been implemented for the reservoir and field models. Examples and case studies have successfully demonstrated the modelling of the hydrocarbon saturation under imbibition and secondary drainage equilibrium, which in extreme cases could co-exist in a field. The results of the saturation-height model in a 3D reservoir model using the fluid contacts information from log data, pressure and seismic are seen to very well align with the saturation log in wells. The residual gas saturation model built from the core measurements is compared with the in-situ residual gas saturation observations from logs. The mobility of residual or trapped gas at reservoir conditions is also discussed. From the examples and case studies discussed, it can be concluded that this new approach for hydrocarbon saturation modelling for fields under a complex fluid fill history of imbibition and/or secondary drainage equilibriums is robust and can be implemented in 3D static model and considered having high potential for dynamic reservoir simulation.
Implementation of Dispersed Gas Model for Kick Tolerance Analysis of an HPHT Exploration Well in Norway
Authors: Karahasan K. , Oyovwevotu J. S. , Vielma W. E. 
Published: November 2017

Abstract
Minimum requirements for kick tolerance (KT) in Maersk Oil corporate standards drove implementation of analysis using a dispersed model instead of a single-bubble model to achieve more realistic KT values for a planned high pressure and high temperature (HPHT) exploration well with oil-based drilling fluids.
The large uncertainty bands of predicted pore and fracture pressures in an HPHT exploration well offshore Norway had driven the casing design, which had very narrow margins and little flexibility in setting depths for the casing strings. KT analysis using a single-bubble model indicated allowable kick volumes of less than the required 50bbl minimum. To comply fully with the 50bbl KT, additional casing strings would be required, with several liners and/or unconventional casing sizes, adding further complexity, cost, and risk to the well and the operations. The development of a well control bridging document, including HPHT procedures, competency assurance of the crew, and use of real-time pore pressure prediction service was considered inadequate to fully manage the associated well control risk.
The benefit of accepting the less than 50bbl KT would be to enable drilling of the HPHT exploration well with the planned five-string casing design, which was already more robust than in most of the offset wells, which utilized a four-string design. With the five-casing-string approach, there is little room for a contingency casing/liner string without possible compromise of some of the well objectives.
An internal dispensation process was initiated due to the noncompliance with Maersk Oil corporate standards. To secure dispensation from such corporate standards, transient drilling modeling software was used to calculate updated KT on the basis of the dispersed kick (gas) model. In addition, a plan was put in place to update the well model and recalculate KT using real-time well information.
This case history presents the story of KT analysis of the subject well, including transient drilling modeling to investigate the sensitivity of input parameters. Furthermore, a description of the software's use to assure safe drilling operations is discussed. Lessons learnt from use of this software during planning and well construction will also be discussed.
Transpressional and Transtensional Structural Patterns in Abu Dhabi Fields, UAE
Authors: Noufal Abdelwahab , Obaid Khalid 
Published: November 2017

Abstract
Abu Dhabi fields profitable development starts with understanding structural framework and styles kinematically and dynamically in the context of regional and local exploration resource potential evaluation. This enables to determine and predict the structural controls on deposition and understand the nature and development of trap styles.
The fault systems in Abu Dhabi fields investigating the different stages of geometrically, kinematically and dynamically development of strike-slip basins. The seismically mapped stratigraphic succession starts with the Permian, that showing fault systems characterized by Late Mesozoic transpressional wrench tectonics. Abu Dhabi mature basins provide important information on the temporal and spatial changes in sediment source, depositional systems, and uplift history of Abu Dhabi fields. A gap is existing between the faults systems interpreted on the magnetic maps that showing NE lineaments and the Permian-Tertiary succession with main faults tending due NW. Below the deeper Permian interpreted horizons and up to the basement is not clear in Abu Dhabi, as the seismic is not cover the deeper section. Therefore, a tectonic model is required that captured the unknown using the known faulting relations with the depositional and deformed rock units.
This work is a multi-disciplined investigation of the complex spatial and temporal relationships between facies distribution and faulting, which exist during basin evolution in a tectonically active intracontinental setting. This exciting field-based study will integrate structural mapping, structural techniques, and seismic interpretation to examine the diverse origins of strike-slip related basins in the UAE. The aim of the fieldwork was to gain a three-dimensional picture for the tectonic system that has operated in Abu Dhabi basins through time, and to understand the interplay between faulting, basin margin deformation, facies distribution, architecture, and adjacent mountain building.
Kinematic analysis of faults for stress determination was carried out on Permian up to Tertiary rocks, which revealed various transtensional and/or transpressional regime. Abu Dhabi deformation was segregated into two coeval distinctive states of stress. The Permian-Cretaceous state of stress was compressional, with σ1 oriented in a NW-SE direction and changed by the Tertiary to be due NE.
This paper address generating reliable distributions of the deformation zones predictions that can impact the reservoir parameters geodynamically within onshore/offshore Abu Dhabi successions where the development induced modifications and their effects on reservoir permeability can be understood and managed.