bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Simultaneous Injection Concept and Other Water Based EOR Strategies for a Carbonate Reservoir in North of the Sultanate of Oman
Authors: Kathel Prateek , Rawahi Zainab , Wunnik Johannes van , Groenenboom Jeroen , Harris Rob , Al Sulaimani Hanaa , Al Mjeni Rifaat , Dhahli Adnan , Balushi Abdul Aziz , Shukri Ibrahim 
Published: October 2022

Abstract
In this study development options are evaluated for a low permeability carbonate field located in the North of the Sultanate of Oman which has been on production since 1969. The dominant recovery mechanism is bottom aquifer water injection with an estimated recovery factor of around 50% till date. This study is aimed at testing the simultaneous injection concept and other water based EOR strategies for the field to present a range of options for future development. During the work several concepts were also designed to understand the impact of major heterogeneities on proposed recovery mechanisms, and to understand the role of gravitational forces on remaining oil distribution.
Major findings of this work include the development of a range of recovery options for the field with incremental recovery ranging from 2% to 20% (Recovery Factor), improved understanding of the impact of heterogeneities and the role played by gravitational forces. The application of "Experimental Design" of simulation runs ensured capturing of the range of uncertainties in heterogeneities and provided a distribution of outcomes. Economics was evaluated for surfactant polymer flood and simultaneous injection concept to facilitate decision making.
Historical Polymer Flood Oil Gain through Outstanding Subsurface and Surface Integrated Operations
Authors: Sawafi Marwan , Kindi Osama , Hashimi Abdulaziz , Ghailani Taher , Maskari Azza , Abri Moh’d , Hinai Suleiman 
Published: October 2022

Abstract
The largest polymer flood field in the Middle East is operating since 2010 with more than 40 polymer patterns and around 300 wells. Following a very diligent and complex operational procedures is essential to deliver the polymer properly to the reservoir. Throughout the past 12 years, this project went through several challenges such as injection uptime sustainability, polymer viscosity stability & polymer pumps uptime which have a direct ramification of the field polymer oil gain recovery.
In 2022, the field realized the highest polymer oil gain since the project commenced, around 50% improvement in the oil daily rate compared to the past three years. These substantial results are consequences of several initiatives such as Polymer viscosity improvements due to better monitoring and improvements on troubleshooting reaction time, sustainable injection uptime with more than 85% though better maintenance & monitoring of the polymer pumps and PSUs and Polymer injection optimization: increasing polymer consumption in good performing patterns and reduce/stop in the lower ones. All these initiatives have led to significant improvements in the polymer utilization factor by around 40%. It is crucial to sustain a good performance and stable operation & injection uptime prior to the polymer phase 3 start-up where more than 400 infill wells are planned to be drilled to expedite the polymer recovery without polymer facility expansion.
The objective of this paper is to shed light on the road map followed to restore value to this great project but also to provide insights to the newly introduced best practices that were developed by Marmul team and can be translated universally to any future polymer/cEOR project.
Thermal Aspects for Chemical EOR Projects Implementation
Authors: Osipov Andrey Valerievich , Bondar Mikhail Yurievich , Groman Andrey Andreevich , Chebysheva Olga Vadimovna , Milchakov Sergei Vasilievich , Kosikhin Anatoliy Sergeevich 
Published: October 2022

Abstract
Chemical methods of enhanced oil recovery in general and SP flooding, in particular, are considered as a promising tertiary method of developing mature oil fields in Western Siberia, with the potential to increase oil recovery to 60-70% of the initial geological reserves [1–3]. The selection of an effective mixture of surfactants and polymer for SP flooding is a complex and multi-stage process. Usually, the choice of chemical composition and modeling on the hydrodynamic model is carried out under isothermal condition at reservoir temperature [4,5,6]. However, recently some authors have been paying attention to the temperature aspects of SP flooding [7]. According to these studies, the change in reservoir temperature as a result of long-term injection of unheated water can play a decisive role in the choice of chemical composition and hydrodynamic simulate of SP flooding. This happens, firstly, due to the fact that the temperature significantly affects the IFT, on which the oil displacement coefficient of the SP composition depends. Secondly, the viscosity of the polymer solution and, consequently, the sweeping efficiency during SP flooding depends on the temperature.
In this paper, the temperature profile was evaluated in the area of the SP flooding pilot site, where flooding with unheated water was carried out for 12 years. Initially, the downhole temperature in the injection well was calculated based on analytical functions, which was then confirmed by field studies. As it turned out, the downhole temperature in the injection well is 42 °C, which is 45 °C less than the initial reservoir temperature.
At the second stage, with the help of analytical functions and hydrodynamic simulation, the temperature profile in the area of the SP flooding pilot site was estimated. Calculations have shown that the injection of unheated water over a 12-year period significantly cooled the reservoir in the pilot area. The temperature in the area of the well designed for injection of the SP composition is 70 °C, which is 17 °C less than the initial reservoir temperature and with further injection of the unheated SP composition, the temperature in the area of this well will fall. This circumstance must be taken into account when choosing surfactants and polymers that must have effective oil-displacing properties over a wide temperature range.
Advanced Technologies Application - A Full Subsurface to Surface Integrated Approach to Meet the Challenges of a Complex Multi Reservoir Carbonate Field CO2 EOR Development
Authors: Xu Siqing , Baslaib Mohamed , BinAmro Ahmed 
Published: October 2022

Abstract
Miscible CO2 flood - similar to miscible hydrocarbon gas injection - is a well-established proven EOR development scheme. There have been a large number of CO2 EOR developments worldwide, with deployment in both carbonate and clastic reservoirs. Potential controlling factors on CO2 EOR incremental production and recovery are well understood and widely published. This paper presents an integrated CO2 EOR development study, with emphasis on advanced technologies application - a full subsurface to surface integrated approach to meet the challenges of a complex multi reservoir carbonate field CO2 EOR development. This paper is a follow up companion paper, presenting additional results, to a previous paper by Xu S. et al (2021). Holistic detailed studies were performed expediting advanced technologies deployment under a CCUS Hub decarbonisation approach. Based on field pilot testing results, multi advanced technologies from subsurface to surface were assessed in a fully integrated manner. These include Maximum Reservoir Contact (MRC) wells, Limited Entry Liner (LEL) and fishbone drilling advanced completion technologies, fishbone surface networking, CO2 recovery unit etc. Significant improvements in incremental oil recovery and project economics were obtained.
Pilot Tests of Enhanced Oil Recovery by Integrating Conformance Control Treatment and Surfactant Flooding for Low Permeability Reservoirs
Authors: Zhou Nancy Chun , Lu Meng , Liu Yajun , Li Jianshen , Liu Fuchen , Li Wenhong , Wu Xinwei , Rao Tianli , Zhao Kun , Yang Lu , Wang Yajun , Gu Renchao 
Published: October 2022

Abstract
For fractured low permeability reservoirs, there are challenges to enhance oil recovery after water flooding with high water cut contents. Because of unsatisfied surfactant polymer flooding, we explored the integrated EOR techniques of conformance control treatment and surfactant flooding. This paper analyzes the results of pilot tests with four injectors and 16 producers and concludes the effectiveness of integrated EOR techniques.
Based on lab results of conformance control core flooding tests and surfactant based chemical EOR reservoir core flooding experiments, we did pilot simulation studies to develop pilot design parameters. Then through history match and detailed compositional simulation, we made EOR integrated technology design and compared several injection scenarios by predicting the potential performance. Finally, an integrated EOR technique with two conformance control treatments and surfactant flooding was selected and executed for three injectors in the interested pilot block. For the fourth injector, only surfactant flooding was used to compare.
Lab results of conformance control core flooding tests showed the efficiency of plugging and a good fluid diversion performance of conformance polymer agents. Surfactant based chemical EOR reservoir core flooding experiments resulted from 70% to 98% residual crude oil recovery. The experimental data obtained was implemented in a numerical simulator model to find the potential incremental recovery associated with conformance control treatments and chemical flooding. A refined sector model used to further evaluate the effect of them. Positive simulation results boost pilot tests. Five fluid injection slugs including the cleaning slug, pre-flooding slug, near wellbore plugging slug, in deep conformance control slug, and surfactant flooding slug were run for three injectors in the range of eight to ten months of treatment. In the interested pilot block, the monthly decreasing rate of oil production dropped from 3.58% before treatment to −1.04% during treatment. Comparing the oil production data from the fourth injector with those from other three injectors, we observed monthly oil production rate increases from 4.25% to 7%. These results highlighted the importance of conducting a conformance control treatment before surfactant flooding, especially in fractured low permeability reservoirs.
The results of pilot tests in this work shed light on designing integrated EOR techniques. These positive results of controlled high water cut and improving oil production are promising enough to go towards a larger field project.
SmartWater Synergy with Chemical EOR: Studying the Potential Synergy with Surfactants
Authors: AlSofi Abdulkareem M. , Wang Jinxun , Salaun Mathieu , Rousseau David , Morvan Mikel , Ayirala Subhash 
Published: October 2022

Abstract
The potential synergy between SmartWater and various EOR processes has recently attracted significant attention. In previous work, we demonstrated such favorable synergy for polymer floods not only from a viscosity standpoint but also in terms of wettability. Recent studies suggest that such synergy might extend to even surfactant floods. In this work, we investigate the potential synergy between SmartWater and surfactant flooding. Opposed to previous work, the potential synergy is investigated from ground zero. We concurrently developed two surfactant formulations for conventional high salinity injection water and low salinity SmartWater. The formulations were designed for an actual carbonate case exhibiting harsh reservoir conditions. To design the two surfactant-polymer (SP) formulations, we followed a systematic all-inclusive laboratory workflow. Oil displacement studies were performed in preserved core samples using the two developed formulations with conventional injection water and SmartWater. The results demonstrated the potential of binary surfactant mixtures of Olefin Sulfonate (OS) and Alkyl Glyceryl Ether Sulfonate (AGES) for both waters. The designed binary formulations were able to form to Winsor type III emulsions besides achieving ultralow interfacial tensions. Most importantly, in terms of oil displacement, the developed SP formulations in both injection water and low salinity SmartWater were capable of recovering more than 60% of the remaining oil in core post waterflooding (ROIC). A key novelty of this work is that it investigates the potential synergy between SmartWater and surfactant-based processes from the initial step of surfactant formulation design. Through such from-scratch evaluation, we demonstrate that surfactant-based processes exhibit limited synergies with SmartWater. Comparable processes in terms of performance can be designed with both high-salinity and low-salinity waters. It is also quite possible that the synergistic benefits of SmartWater on oil recovery cannot be effective in SP flooding processes especially under optimal salinity conditions.
Innovative Process to Set Record Length of Cement Plug in an Offshore ERD Well
Authors: Latinovic Mile , Verhozin Andrey Konstantinovich , Klementyeva Natalia Andreevna 
Published: October 2022

Abstract
From an operator’s standpoint, well abandonment is viewed as a costly, but necessary, process that does not typically add value. The service company is tasked with performing the abandonment operations safely, efficiently, and economically without issues. This paper presents a technique for the placement of an extremely long, single cement plug using sacrificial pipe and a special release tool under conditions that significantly exceeded the limits attempted by the industry previously.
The plug and abandonment (P&A) process with conventional balanced-plug methods presents many challenges, particularly in the case of multiple cement plugs in a long, extended-reach drilling (ERD) section covering several permeable intervals. The most common issue is cement contamination, which results in poor zonal isolation caused by insufficient slurry strength. A special downhole tool was used for this operation, which provided a reliable solution for placing one long cement plug instead of placing up to 10 balanced plugs, thereby decreasing operational risks and saving rig time.
This fit-for-purpose tool is torque-capable, which enabled running sacrificial pipe in a wellbore with high inclination, where right-hand torque up to 30,000 lbf-ft was necessary to reach TD. Equipment could be drillable or nondrillable; in this case, a nondrillable solution consisting of 7-in., 26-ppf steel casing used as the sacrificial pipe. A dart was used for the displacement of cement through the pipes and activation of the releasing mechanism to place the sacrificial pipe in the hole. The P&A operation was performed on a 9750-m MD ERD well with an inclination of 78 to 84° in the abandonment interval of an offshore drilling rig in Russia. One cement plug covered 2550 m of sacrificial pipe, isolated several zones, and saved two days of rig time.
This procedure did not require pulling pipe out of cement. The risk of cement contamination was significantly diminished, and further operations could be performed immediately after the release. An added benefit was the reduction in contaminated mud that would require treatment and disposal compared to the multiple conventional balanced-cement plug techniques. Tool manufacturers are challenged to continue developing higher torque capacity tools to meet the demands of future ERD P&A activity.
A Challenge for Making a Risk Map of Lost Circulation Based on Geomechanical Evaluation in a Complex Carbonate Reservoir in Offshore Abu Dhabi
Authors: Tsusaka Kimikazu , Saito Shun , Toma Motohiro , Goyara Yassar Goyara , Yudhia Denya Pratama , Fukuda Kengo , Toki Takahiro , Matsubuchi Hitoshi 
Published: October 2022

Abstract
We present a root-cause analysis of severe lost circulation and creation of its risk map in an offshore oil field, Abu Dhabi. Lost circulation of more than 100 barrel per hour (BPH) has occurred in sixteen (16) boreholes through the carbonate reservoir. Four (4) out of them experienced total loss. The authors investigated spatial distribution of lost circulation and allowable maximum overbalance based on review of drilling operation in nearly two hundred (200) boreholes. The critical overbalance to reactivate the natural fractures for the tensile-opening or shear-slip failures was analyzed by using geomechanical model. The present study clarified that most of severe lost circulations occurred at the specific sub-layers of the reservoir. The core observation showed that lost circulation occurred in the intervals in which fragmented rocks (rubbles) and fractures were distributed together. The fracture stability analysis revealed that the conductive fractures interpreted by borehole imager were geomechanically stable under conventional overbalance applied in drilling through the reservoir sections. Namely, the planer fractures were geomechanically stable under the current in-situ stress condition. The study concluded that the predominant root-cause of severe lost circulations in the carbonate reservoir was cave-related rocks (cave facies) and excessive overbalance applied to reservoir pressure. The cave facies were supposed to be formed by flank-margin cave system and its collapse due to deposition of overburden formations. A risk map of lost circulation defined the five areas with its potential risk. The risk map indicated not only the risk level of lost circulation but also practical recommendations on the depth to set casing and allowable maximum overbalance. It functions as a practical guide for the design of boreholes in the ongoing drilling campaign.
Assessment of Shape Memory Polymer Sand Control Performance and Integrity under Field Conditions via Geomechanical Simulation
Authors: Gandomkar Arjang , Guises Romain , Pedreira Jose 
Published: October 2022

Abstract
A porous shape memory polymer (SMP) product is currently deployed in oil and gas wells as a sand control system. This thermally and chemically activated polymer is emerging as a smart material due to its ability to recover to a predetermined shape following environmental manipulation, even after large wash out beyond gauge hole. The SMP is molded in a cylindrical geometry with desired inner and outer diameters for oil and gas production wells. This innovative technology has proven to be a reliable sand control media, a required step in combating sand production, protecting equipment and increasing the well lifetime [1, 2].
Material properties must be known in order to define the behavior of a SMP for evaluating its application in field application. The purpose of this paper is to establish a workflow in determining the material properties necessary to describe the behavior of SMP and study SMP integrity and performance under field conditions deployed in a wellbore during hydrocarbon production. For this purpose, a finite element model coupled with dynamic fluid lab data has been designed to estimate the material properties. Hyperelastic and viscoelastic constitutive models best describe the behavior of the SMP materials. The non-linear and non-elastic behaviors of the material makes the analytical solution approach inefficient, so a finite element modeling approach has been employed to overcome this difficulty. Several lab tests at different temperature conditions have been performed to expand the knowledge on material behavior. Results in this paper suggest the designed techniques and workflow are suitable in predicting material properties of SMP under any temperature conditions.
Finally, a separate finite element analysis is formulated for assessment of geomechanical loads and deformations on the SMP. A 2D fully coupled poro-elastic finite element model including geomechanical load, depletion, and drawdown effects is utilized to quantify load, strain, and permeability changes of the SMP system during production and depletion. Impact of geomechanical load during production that may reduce the permeability of the SMP and affect production was evaluated for an offshore wellbore.
Regional Assessment of the Upper Jurassic Hanifa and Tuwaiq Mountain Formations, Abu Dhabi: Implications for Prospectivity
Authors: Aitken John F. , Chitrao Amogh , Xie Anni , Fadipe Oluwaseun , Al Shamsi Jawaher , Vantala Aurifullah , Al Tameemi Kate 
Published: October 2022

AbstractThe Hanifa and Tuwaiq Mountain formations (Upper Jurassic Sila Group) are underexplored units in Abu Dhabi. Although there are several discoveries from the Hanifa Formation, both onshore and offshore, and encouraging indications in the Tuwaiq Mountain Formation, the conventional potential of these formations has not been fully realised. Uncertainties exist between onshore-offshore and west-east correlations, with conflicting stratigraphic terminologies, and the distribution of the Hanifa and Tuwaiq Mountain formations across Abu Dhabi, particularly details of facies distributions and transitions and their impact on the distribution of depositional environments through time.To reduce uncertainties and unlock resources a fully integrated study of the lower Sila Group across Abu Dhabi Emirate has been undertaken. Approximately 150 wells were correlated and integrated with the interpretation of six regional seismic transects (3 W-E and 3 N-S). More detailed interpretation over areas with 3-D seismic coverage helped to improve stratigraphic understanding. Cored wells were used to refine sedimentological interpretationsand extrapolated into uncored wells.Resolution of stratigraphic uncertainties mean that, for the first time, there are consistent lithostratigraphic and sequence stratigraphic schemes across Abu Dhabi Emirate that provide a reliable framework for basin modelling and play mapping. Furthermore, integration of all the sub-studies has led to the development of new depositional models and more detailed GDE maps. These are important inputs to basin modelling and the development of revised play maps that clearly highlight the prospective areas in Abu Dhabi. Focus on these prospective areas has led to the recognition of a significant number of structural leads and three new stratigraphic play concepts. These concepts include: a truncation trap geometry to the east,a possible collapse/mass movement trap on the slope, anda possible combined stratigraphic/structural trap where four-way dip closures overlap both the shoal and the slope, with the facies change to muddier slope deposits providing potential down-dip seal.