bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined Viscoelastic Surfactant and Induced Imbibition for CEOR of Low Permeability Reservoir
Authors: Hongyan Cai , Yi Zhang , Jianguo Li , Maozhang Tian , Wenli Luo 
Published: November 2017

Abstract
Presently, water flooding low permeability reservoirs face severe development challenges, such as early water breakthrough, low productivity, and low recovery. In view of this, a CEOR method combined by warmlike micelle and surfactant imbibition was recommended and detailed in-lab evaluations were performed.
Warmlike micelle (WLM) made from viscoelastic surfactant (VES) has special rheological characteristics, showing great potential for swept volume increasing through viscosifying effect in low permeability reservoirs. Some surfactants can induce spontaneous imbibition through capillary force effect, wettability alteration, and oil film removal to enhance recovery. Herein, warmlike micelle and surfactant imbibition were combined to both increase swept volume and induce spontaneous imbibition.
Rheological properties, imbibition recovery, and core flooding performance were evaluated for a reservoir with average permeability of 3.51 ×10-3μm2. At shear rate of 7.34 s-1, the viscosity of 0.30% VES solution amounted to 25.4 mPa.s at 70 °C. Static imbibition test by outcrop showed imbibition recovery of 68.7% was achieved by surfactant AEC. After that, three runs of core flooding tests were conducted to evaluate the performance of prepared formulations. For VES only formulation, an incremental recovery of 8.50% was obtained after water flooding with recovery of 32.81%. For the combined VES and surfactant imbibition formulation, 14.82% incremental recovery was achieved. Synergistic effect of VES and spontaneous imbibition motivated more remaining oil because of dual effects.
The developed CEOR method takes advantages of VES and imbibition, demonstrating promising potential for further development of low permeability reservoir.
Development of Comprehensive Inspection Program for Drill Bits Through Joint Industry Project for Failure Risk Mitigation and Reduction of Inspection Costs
Authors: Mulunjkar A. M. , Durairajan B. , Williams J. , Griffo A. , Gokhale S. R. , Wells A. 
Published: November 2017

Abstract
There is an absence of industry-wide, globally accepted standards that provide comprehensive inspection procedures and acceptance criteria for inspection and maintenance of drilling bits, including: wear, cracking, and mechanical damage criteria for bit bodies and cutting elements. Nevertheless, bits are routinely inspected and evaluated to determine their usability for both land and offshore drilling operations. This creates significant risk for all drilling operators because the lack of clear inspection criteria can lead to the use of bits with flaws causing downhole failures. In addition, the lack of an industrywide bit inspection specification has challenged bit suppliers since the decision to use a bit with indications and damage can be subjective and the potential risk severity can be high.
Industry standards like API, ISO and DS-1 for inspection of other drill stem components do exist. However, the application of these standards to bits, particularly those with matrix bodies, is inappropriate. Using acceptance criteria adopted from existing standards for other drill stem components creates significant risk by accepting minor damage and rejecting major damage without an industry accepted standard. To overcome these limitations, a technical committee consisting of operators, drilling contractors, service providers, manufacturers, and inspection companies, worked together to develop specific procedures and acceptance criteria for the inspection of bit bodies as well as cutting elements.
This paper presents the procedures and acceptance criteria developed by the technical committee that address the inspection of cracks and porosity in matrix and steel bit bodies, wear and erosion of bit bodies, cracks in PDC cutters, and other damage to cutters. The information included in this paper was considered for development of the DS-1 Bit Inspection Technical Standard (BITS) to address the necessity of a globally accepted standard for the inspection of bits.
Integrated Fracturing Services Project: A Success Story of Collaboration Between Operator and Service Company
Authors: Sayapov E. , Nunez A. J. , Al Gheilani H. , Ibrahim E. G. , Al Ghaithi A. , Al Salmi M. , Al Farei I. , Kelkar S. K. , Kurniadi S. D. , Al Zeidi O. , Barakat A. M. , Al Kalbani M. S. 
Published: November 2017

Abstract
An integrated fracturing services (IFS) project between Petroleum Development Oman (PDO) and Schlumberger started in November 2009 and spanned a 7-year period until November 2016. It steered the local fracturing industry from standalone operations to an integrated package, offering collaborative services between hydraulic fracturing, coiled tubing, and well testing services. The synergies between the various services allowed for a more streamlined decision-making process between the operator and the service company. Ultimately, this led to faster well delivery times, lower non-productive time, and maximum utilization of personnel.
The integrated approach was primarily based on communal resource pooling which was available for any of the services on location at any given time. At its prime, the IFS project comprised of 4 fleets deploying almost 300 employees across the Sultanate of Oman's northern and southern fields. The coordination process was centralized and handled by a dedicated team in charge of logistics, transportation, personnel, and resources. This centralization process was essential for the IFS workflow, and it was primarily managed by the service company in collaboration with the operator's well engineering team.
Tangible results were achieved, and the IFS model added a new dimension to the fracturing industry in the Sultanate. It allowed the operator to align its well development operations with its production goals and delivery times. It also provided the service company with an opportunity to bridge operational and communication gaps, which would have been harder to achieve if other vendors were involved. These high-level results were coupled with operational successes by the fracturing, coiled tubing, and well testing crews.
The novelty of this project is in the dynamism of all available communication channels, as well as the elimination of operational lag due to the reduced number of vendors in any given location. The success of the IFS program makes it PDO's first-choice fracturing model, especially during the current downturn when lowering operational costs is of utmost importance.
Carbonate Clinoforms, Sinkholes, Reefs, and Flow Units: Integrated Seismic Reservoir Characterization in Shuaiba Formation UAE
Authors: Strecker Uwe , Ibrahim Mahmoud Mudi 
Published: November 2017

Abstract
Integrated seismic reservoir characterization of carbonate rocks potentially thwarts difficulties arising from reservoir heterogeneity owed to a complex geological history. The featured interdisciplinary workflow reconciles geological, geophysical and engineering components to address reservoir complexity in terms of stratigraphic architecture coupled with a distribution of layer properties that honors flow zonation. Primarily, this workflow calls for a combination of hydraulic flow unit definition embedded in sequence stratigraphy and is further augmented by seismic attribute analysis (i.e., seismic inversion, frequency decomposition of amplitude, etc.), rock physics, and geostatistical techniques to characterize an UAE onshore oil reservoir located within a Lower Cretaceous carbonate sequence (i.e., lower member of Shu'aiba Formation; Strohmenger et al., 2010). Our results to-date encourage us to further characterize the reservoir applying geostatistical techniques (seismic stochastic inversion, fuzzy math) in a future companion paper.
Integrated Characterization of the Regional Aquifers in Abu Dhabi Onshore. Dammam, Umm Er Radhuma and Simsima Formations. UAE
Authors: Parra Humberto , Ghosh Dipankar , Tahir Sofiane 
Published: November 2017

Abstract
Regional aquifers are critical for development of oil/gas fields that need water injection for pressure maintenance. However, modeling of regional aquifer is a difficult task as data acquisition and analyses are primarily focused on hydrocarbon bearing intervals. Also, aquifers are generally regional, whereas the data available is clustered around oil/gas fields with negligible data in the vast areas lying outside the fields of interest. The present study aims at building a regional aquifer model for Abu Dhabi Onshore area integrating all the available data in different scales that may be used in planning future availability of water resources.
Most of the oil/gas fields located in Onshore of Abu Dhabi have so far been developed by primary pressure maintenance strategy injecting water obtained from the shallower Late Cretaceous, Paleocene and Eocene aquifers. The main water source reservoirs are Dammam, Umm Er Radhuma and Simsima formations. Despite limited data availability, the study delivered a fit for purpose 3D reservoir model integrating seismic data, regional outcrop analogs and available log and core data. An enormous database containing 4768 wells from 10 most important Fields of onshore Abu Dhabi was used to build the structural framework with the help of regional seismic interpreted surface. Sequence stratigraphic cycles were identified in all the formations considering eustatic curves and correlation using GR-NPHI-RHOB logs. Average layer thickness was designed to be around 20ft in all the reservoir intervals. Input for property model was very limited as logs and cores are generally not acquired in aquifer intervals. Wells with NPHI-RHOB logs were used for estimation of porosity and it was calibrated with limited core porosity data available. Permeability has been computed by fitting functions to Poro-Perm cross-plot and then adding statistical dispersion based on observed core permeability data. Different scenarios of permeability were defined due to the high dispersion in the core data. For dynamic modelling three equilibration regions were setup for the main three aquifers and a common PVT table was used. All the water supply and disposal wells were used in history matching. The high case of permeability was found to honor best the production and injection data.
The static model built integrating all available data in different scales is robust. Although limited data availability for property modelling was a major concern, the model did show reasonable history match and is fit for purpose to predict future water supply. A systematic data acquisition plan for these aquifers may be implemented in future to make the current model more reliable.
The regional aquifer model of Abu Dhabi Onshore is the first of its kind in the country that incorporates all the available information including seismic interpretation in regional scale to small-scale core data.
Surface Complexation and Equilibrium Modelling for Low Salinity Waterflooding in Sandstone Reservoirs
Authors: Elakneswaran Y. , Shimokawara M. , Nawa T. , Takahashi S. 
Published: November 2017

Abstract
Changes at oil/brine and sandstone/brine interfaces can improve oil recovery in sandstone reservoirs by low salinity waterflooding (LSWF). There have been several attempts to understand the interfaces through both experiments and modelling, but the results are inconsistent and the existing models did not consider the important mechanisms on prediction. In this study, an integrated model incorporating surface complexation reaction, dissolution/precipitation of minerals, and speciation was developed to simulate LSWF in sandstone reservoirs. A separate surface complexation model was developed for oil-brine and kaolinite-brine interfaces. The effect of pH and divalent ions of calcium and magnesium concentration on surface species of oil and kaolinite is analyzed. These surface complexation models were combined and coupled with phase-equilibrium model to predict LSWF in sandstone reservoir. Deprotonation of Al and Si sites (&gt;Al: SiO−) of kaolinite and both deprotonated carboxylic groups (−COO−) and calcium-adsorbed (−COOCa+) dominates the surfaces at various brines and its diluted composition. The pH rise in the formation water increases the dissociation of both oil and kaolinite and hence high repulsion between the surface. The desorption of oil was calculated from the surface species concentration of both oil and kaolinite. The simulation results on desorption of oil increases with dilution times (up to 20 times) and amount of equilibrated brine of seawater, formation water, 20 mmol/l CaCl2, and 20 mmol/l MgCl2. Consideration of phase-equilibrium significantly impact on the simulation results; the dissolution and precipitation of sandstone minerals increase the desorption of oil by few percentages, 6-10% in seawater flooding. Increased oil recovery in LSWF is strongly depend on the aqueous chemistry of injected solution and surface electrical properties, such as surface site density and equilibrium constants for ionization and ionic adsorption of oil and kaolinite. The simulation results of this study emphasize the importance of surface chemistry of oil and kaolinite as well as phase equilibrium reactions on improved oil recovery in LSWF. The key factors affecting electrostatics of oil and kaolinite and then oil recovery was identified and analyzed. The potential improvement of the model for better prediction is discussed. The proposed model could serve as a useful tool to predict oil recovery during LSWF in sandstone reservoirs.
World Drilling Limit Envelope: Why it Shows an Irregular Triangle?
Authors: Li Xin , Gao Deli , Jiang Zhenxin , Li He , Zhang Hui 
Published: November 2017

Abstract
Many scholars have carried on the related researches of world drilling limit envelope and provided the TVD (true vertical depth)-HD (horizontal displacement) charts. Those charts show that both the ultra-deep well and the extended-reach well (ERW) with extremely high HD-TVD ratio are relatively rare, while those wells have a certain TVD as well as a certain HD formed the majority part of these charts. Why the envelope shows an irregular triangle as a whole? There exist theoretical reasons except for the reasons of economic benefits and drilling needs. This paper mainly analyze the following four kinds of well: 1) the ultra-deep well; 2) the vertical well and the directional well with identical TVD; 3) the horizontal ERW; 4) two ERWs with identical measured depth (MD). These analyses can be used to explain why the world drilling limit envelope shows an irregular triangle. The research shows that drilling limits are restricted by borehole space, well deviation, bearing capacity of drilled formation, mechanical factors and hydraulic factors simultaneously. These factors working together make the world drilling limit envelope as an irregular triangle. The factors that limit the well’s MD can be divided into two categories: subjective factors and objective factors. The subjective factors can be broken by upgrading the drilling equipment and improving the drilling technology. However, the bearing capacity of drilled formation is an objective factor which cannot be changed. It is the ultimate factor that restrict the drilling limit. In addition, some optimization control measures are proposed, which are beneficial to break the world drilling envelope.
Building the Next Generation of Petrotechnical Professionals through Gamification
Authors: Ugoji Paul , Ibhadode Akii , Amadi Anslem 
Published: November 2017

Abstract
There is a gradual awareness which indicates some level of shortage in the generation of technically skilled manpower for the petroleum sector and other industries. With an increasingly ageing experienced work force, funding constraints for training, increased employee turnover, reduced field exposure, reduced interest from graduates etc, there is need to reassess the mode of teaching and man power training for the petroleum sector in our various institutions considering the fact that the education sector stands as the main source of personnel generation for the sector.
This paper tries to highlight the skills and employability needs of employers from different sectors with special focus on the petroleum sector. With these needs as a guide, an appropriate gamification strategy that would provide the required outputs for employers is being implemented with emphasis on key gaming components missing in our educational system. That way, graduates from tertiary institutions would be fully equipped for work immediately after graduation since they would have been exposed in a fun-filled way to issues that are important to employers of labour. This plan would also enable higher institutions to highlight areas of study and interests that they lack. The government and private sector, especially the oil and gas sector, can then play a positive role in enhancing their academic curriculum.
A pilot program was undertaken in 2016/17 with the gamification of multiple facilities that have links to the petroleum industry. This was setup at the Federal University of Petroleum Resources, Effurun, Delta State, Nigeria and the feedback from the participants has been included in this paper. The program would be made to gradually evolve over time in the hope that its coverage would be enhanced such that employers would find it easy to spot and acquire outstanding student talents with the specific qualities they need directly from various institutions even before graduation. This way, general training costs required by companies in the petroleum sector would be reduced since various institutions would have covered most of their key needs due to the infusion of critical skills developmental elements into the gamification process.
ERD Wells on Remote Artificial Islands: Successful Optimization Strategy to Boost a Performance
Authors: Ruzhnikov Alexey , Banda Maria Yanez , Malagon Cecilia , Al-Wahedi Khalid , Toki Takahiro , Benygzer Mhammed , Singh Rudra , Alzate Jose , Kasem Youssef 
Published: November 2017

Abstract
From the start of the drilling campaign on the remote Satah Al Razboot (SARB) artificial islands located in United Arab Emirated (UAE) the operator used multiple optimization initiatives to enhance drilling performance and well delivery.
Even though the complexity of the wells increased over time, when extended reach drilling (ERD) envelop started to expand, with the implementation of optimization initiatives the well construction time significantly decreased. This paper describes the way of thinking and steps taken to boost the performance to the absolutely new level for the operator.
The main objective in actual harsh economic conditions was to drill the wells under the budget without jeopardizing well integrity, service quality and HSE. The ultimate goal was to decrease well construction time by 25%. To achieve this goal, several well construction optimization workshops were organized aiming to challenge and find improved drilling processes, operations procedures, tools, equipment and well design, as well as to have a clear plan on smooth expanding ERD envelop.
In addition with the workshop initiatives, an Operational Performance Improvement Plan was developed aiming to analyzed all operational opportunities to reduce time; a dedicated well engineering, subsurface and operations team was set up to lead the feasibility studies and ensure the implementation of the approved initiatives.
Implementation of all performance improvement initiatives required a balance between all involved parties. Every decision should be verified by multiple teams, included but not limited by drilling, equipment, completion, subsurface, production and intervention. Once the approval is obtained then the initiative is implemented and analyzed, taking into account increasing complexity of the wells and lesson learnt captured. At the same time not all the initiatives were implemented – some were rejected due to significant increase of service quality risk; some due to HSE associated risks. The implementation of the initiates and ideas contributed to the reduction of flat time, elimination of online operations, etc.
The manuscript describes the steps taken to drill extended wells within shorter time compare to standard deviate and horizontal wells. It highlights main challenges faced during implementation of the performance improvement plan and describes techniques and technologies used to overcome them.
On the Importance of SCAL Integration with Key Geologic Controls for Better Field Performance Prediction: A Case Study from a Giant Carbonate Reservoir, Offshore Abu Dhabi
Authors: Selvam Balki , Al Harbi Manal , Herrmann Rolf , Dachang Li , Al Zawa Hesham , Ottinger Gary , Patterson Joe , Al Neyadi Abdulla 
Published: November 2017

Abstract
Accurate assessment of water movement is critical for reservoir performance predictions. It not only impacts the oil production rate and ultimate recovery but also has implication on the development cost and the facility designs, especially when the field is undergoing a major development expansion phase. The carbonate reservoir of interest is situated within a giant oil field in offshore Abu Dhabi. Consequently, robust, reliable application of SCAL (relative permeability and capillary pressure) data is increasingly important to accurately capture dynamic subsurface behavior ahead of field development/production.
The field has been active for 40+ years with early production data dominated by vertical/deviated wells while the late production data is dominated by horizontal wells. During the recent comprehensive SCAL program, high quality SCAL data have been obtained showing more capillary pressure contrast between dominant rock types than the existing data. With the old SCAL data, it was difficult to match the early and late life production data, since each phase showed distinct trends and different fluid displacement dynamics. History matching of the field using the new SCAL has offered new insights into the key geologic controls namely the high-permeability streaks (HKS) and stylolites. The horizontal and vertical spatial distribution and the geometrical dimensions of the high-permeability streaks are uncertain, while dynamic simulations demonstrate their impact on the fluid behavior. While specific zones tend to have a higher preponderance of high-permeability streaks, individual high-permeability streaks are not correlateable from well to well and are usually only a few inches thick. Understanding the distribution of these high-permeability streaks is essential in explaining production behavior especially at the pattern level. Another key uncertainty is the degree of stylolite competence with reduced vertical permeability (Kv), restricting the flow in horizontal zones and resulting in a complex multilayer sweep behavior.
The paper will provide an insight on the workflows that allowed to reduce the inherent uncertainties of the key geologic controls, responsible for delaying water movement from injectors to producers. The detailed understanding of the dynamic reservoir conditions associated with stylolites and high- permeability streaks enabled successful improvement of the historical water cut and pressure match of the reservoir model, leading to a reservoir model with reduced uncertainties in the prediction model and hence to a more reliable field development plan.