bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mineralogy and Geomechanical Analysis for Hydraulic Fracturing: An Integrated Approach to Assess Rock Fracability in Sandstone Reservoirs
Authors: Alsaif Noor A. , Hage Ahmad R. , Hamam Hassan H. 
Published: November 2017

Abstract
A comprehensive integrated methodology is presented that assesses rock hydraulic fracability using rock geomechanics, mineralogy, and chemical compositions. This petrophysical multi-min based approach utilizes sonic and density log data to relate mineralogy and geomechanics to rock stiffness and its susceptibility to fracture.
Rock fracability is assessed in terms of compressional and shear transit times from borehole acoustic logging. These transit times are used to calculate Poisson's ratio and Young's modulus that provide an indication of the tendency of a rock to fracture while preserving the opening of the fracture. The lower the Poisson's ratio, the more brittle is the rock and the higher the value of Young's modulus. Brittleness index and fracability index are introduced to predict fracable rocks; sands with a brittleness index of 50 and higher and fracability index above 0 and less than 1 are fracable candidates.
This geomechanical analysis is combined with rock mineralogy to make conclusive predictions about rock fracability. Rocks rich in silicates and sufficient clay volumes exhibit high rock fracability while ductile rocks negatively impact fracability. The success of the hydraulic fracturing jobs was observed to be directly related to rock mineralogy. The mineralogy groups for the wells in study were silicates (Quartz and Orthoclase) and clays (Illite, Kaolinite, and Chlorite). Quartz associated with sufficient Illite volumes promoted fracability. However, high contents of Kaolinite led to unfavorable results, whereas small quantities of Chlorite positively impacted fracability and promoted well deliverability. The integrated approach showed good predictability and consistency of rock fracability with a certain degree of error (within 10%).
This approach has been applied successfully on different sands with a wide variation in chemical compositions. It can predict wells with the highest success rate of the fracturing operation, save the injectivity test, minimize the fracturing costs and optimize the economics of tight reservoirs.
Main Oil Line Pump Seal Failure Prevention; Advanced Simulation and Case Study
Authors: Khalaf A. M. , Al Omari A. M. , Al-Sherif A. H. , Toubar A. , Barsoum I. , Karrech A. 
Published: November 2017

Abstract
Main oil line (MOL) pumps are responsible to deliver the produced oil from an oilfield to a processing and storage facility where oil is exported through a loading station. MOL pumps failure is considered disastrous due to the fact that it introduces a safety hazard and leads to business and operational interruption. This paper studies a failure prevention approach of MOL pump bearing isolator/seal using computational mechanics simulation to predict the failure and maximize pump reliability.
This research conducted is a case study of failed MOL pump bearing isolator, made of Teflon, which occurred during the pump's Factory Acceptance Test (FAT). The pump capacity is in the magnitude of 250,000 barrel/day. A Finite Element (FE) axisymmetric coupled steady state temperature-displacement model of the bearing isolator was developed. The FE model mimics the actual pump operating conditions to simulate the seal performance. FE results of two different materials, Teflon and Bearing Bronze, were assessed and compared against seal behavior during pump testing. Recommendations to prevent future on-site failures were made and executed based on FE outcomes.
During MOL pump FAT, a Teflon bearing isolator repeatedly failed while running under its normal operating conditions. It is found that the isolator's rotating part is deflecting during operation due to the effect of centrifugal force and thermal growth. This deflection causes the rotating part outer diameter to contact, radially, with the stationary part leading to frictional heat generation and subsequent component rupture. The built FE model was utilized to analyze the failure pattern. The FE model predictions were able to identify the exact location of the failure, under the actual operating speed and temperature. Excellent agreement between FE analysis results and actual failure was observed. In order to prevent this failure from occuring at site, change of material was proposed to improve the seal performance. Another FE analysis was built utilizing Bearing Bronze material, which is a commonly used material for this application, to examine the bearing seal integrity under the same operating conditions. FE results showed that Bronze is able to perform without failure due to relatively negligible deformations. Bronze material seal was then adopted and tested with no failure. The risk of Teflon seal premature failure was hence eliminated.
Bearing isolator selection criteria are not sufficiently covered in any international standard. Operating companies depend solely on manufacturer recommendations. Bearing seal failure due to pump rotation can be analyzed only with advanced engineering simulation due to its dynamic behavior and access limitations. The outcomes of this assessment were able to predict/prevent MOL pump bearing seal failure. This will allow taking action before failure takes place, and provide a material selection guideline for such machine element.
State of the Art Biodegradable Diversion Technology Applied on Tight Carbonates Reservoir Leads to Maximized Production
Authors: Gonzalez David , Ulloa Joel , Safari Reza , Al-Rawi Aws , Babey Andrew 
Published: November 2017

Abstract
The need for diversion in acid stimulation jobs has become a necessity with which we cannot dispense. Various diverting agents are available commercially and can be used effectively when there is a low to moderate permeability contrast as well as porosity. If there are long intervals with high permeability intermixed, mechanical diverter would almost be considered as the sole solution especially when zonal isolation by the means of specialized tools is not required.
This work is aimed at the outcome from using a solid particulate diverter which is a biodegradable particulate diverter that maintains its diversion effect for as long as needed. By controlling certain factors, the diversion time can be increased or decreased. The diversion technique was first introduced to the Middle East in December 2016 to assist in finding a solution for the high permeable intervals that exist in Iraqi wells. The wells need to be matrix acidized and post stimulation PLTs show that production is coming from the high permeable intervals whilst other intervals that have lower permeability, showing no or low production because of the uneven treatment of the zone.
Lab tests were conducted to formulate a suitable carrier fluid that would possess optimum viscosity helping transport the solid particulate diverter system to the intended area. Along with, a suitable breaker fluid that would cleanly break the carrier fluid at the end of the treatment to assure efficient flow back is tested. Temperature and pH were maintained to simulate downhole conditions and achieve the most accurate results.
The job was successfully designed, prepared and performed. Real time optimization was conducted during the job which resulted in a more efficient operation.
The first observed post stimulation results was an increase of 5 m3 per hour. Two days following the stimulation, the records showed an increase in the production rate by approximately 25%.
Functions of Nanoparticles and Surfactants in Enhanced Oil Recovery: Molecular Dynamics Studies
Authors: Mazyar Oleg A. , Darugar Qusai A. , Khabashesku Valery N. 
Published: November 2017

Abstract
The roles of nanoparticles in enhanced oil recovery (EOR) are typically associated with stabilization of foams and emulsions (Fakoya et al. 2017) and with oil detachment due to creation of wedge effect in confined oil-water-rock contact region (Wasan et al. 2003). This publication focuses on these and other functions of nanoparticles in EOR applications, often performed in synergy with surfactant mixtures, e.g. abrasive removal of oil films from rock surfaces, wettability alteration, and improved transport of surfactant molecules through porous media.
Conventional and non-equilibrium Molecular Dynamics (MD) techniques were applied to simulate behavior of nanoparticles and surfactant molecules on oil-water-rock interfaces in stationary and flow conditions and compute the energies of interactions between the components of the studied systems as well as interfacial tensions in them.
Moving nanoparticles were found to be effective in detachment of oil film from rock surfaces. Increased temperature and addition of surface-active agent further enhance the oil-sweeping capability of colloidal nanosuspensions.
Changes in interfacial tension as well as density profile computations showed that functionalized silica nanoparticles and related surfactant-nanoparticle compositions clearly exhibit surface active properties on oil-water interfaces that can be fine-tuned and utilized in EOR applications.
The wettability-altering potential and surfactant-transporting capability of nanoparticles are also demonstrated.
Oil-sweeping, wettability-altering, and surfactant-transporting capabilities of nanoparticles are demonstrated on the molecular level for the first time. Authors also believe that it is the first systematic numerical study of nanoparticle's and surfactant's contribution to the changes in interfacial tension on oil-water interface.
Maximizing Cost Efficiency & Enhancing the Culture of Cost Consciousness Through Workforce Engagement
Authors: Khan Shahla , Saadi Israa Al 
Published: November 2017

Abstract
In February 2016 and in response to the difficult market conditions that had beset the oil and gas industry, Dolphin Energy launched The CORE Project – a long term cost optimization program.
Standing for Cultural Change, Optimizing Productivity, Resourcefulness and Efficient Expenditure (C.O.R.E), the Project was designed to generate significant cost savings and enhance a culture of cost consciousness. This paper outlines how the Project was implemented through the direct involvement of Dolphin Energy employees, who were tasked with providing ideas and suggestions that would help optimize costs and drive significant efficiency improvements to achieve long term, sustainable results.

Methods, Procedures & Process
To drive efforts across the company and ensure long term commitment, a collaborative ‘bottom up’ approach was created. Twenty nine Division/Department Champions were appointed in Qatar and the UAE while a governance structure was put in place, monitored by a Steering Committee and chaired by the General Manager - Qatar. The project is managed through three main phases:
To help drive engagement, the Project has been supported by a comprehensive communications program. This has been designed to provide regular updates on the program, to help maintain momentum, celebrate success and reward employees for their commitment.

Results, Observations, Conclusions
In the past 18 months, employees have generated more than one thousand ideas, of which more than 244 ideas have been converted into initiatives that have led to significant cost savings.
The project has also created tangible cultural change and has made employees more cost conscious and aware.
The CORE Project has received many enquiries from Dolphin Energy's peers in the Oil and Gas industry and the company has been proactive in sharing this experience with its shareholders, and its strategic partner.

Novel/Additive Information
This paper will help highlight the benefits of employee engagement and would be of interest to companies looking to use the workforce to drive tangible, sustainable results.
The CORE Project is a strong example of the effectiveness of a collaborative, ‘bottom-up’ approach, with ‘top down support’ and demonstrates that by involving everyone at the company amazing outcomes can be achieved.
Invisible Lost Time Reduction and Drilling Risk Management Optimization in United Arab Emirates Onshore Field
Authors: Cantarelli Elena , Kojadinovic Nenad , Le Khoa Pham , Salem Gamal Youssef 
Published: November 2017

Abstract
A new workflow was implemented for the first time in three UAE onshore wells with the primary objective being to increase drilling efficiency while managing the associated risks.
The workflow combines proven technologies, software and wellbore surveillance services to deliver risk-free wells ahead of authority for expenditure (AFE) targeting the reduction of nonproductive time (NPT) and invisible lost time (ILT), together with risk management.
The workflow begins with a preliminary field analysis to identify the main challenges and areas that needed improvement. The observations are consolidated on a comprehensive drilling road map by well section that are used to outline prevention and mitigation measures, expected rate of penetration (ROP) and recommended drilling parameters. The study also allowed for identifying performance benchmarks such as average and on bottom ROP and connection time. Key performance indicators (KPI) were developed to monitor progress and track the well with respect to well improvements versus the benchmarks identified. The selection of the monitoring tools and modules required during the execution phase was developed based on the risks and KPIs identified during the field study and were further tailored to target specific challenges such as stuck pipe prevention, hole cleaning, shock and vibration, and connection time.
The workflow enabled the flawless execution of three onshore wells ahead of AFE with zero NPT. The closed loop monitoring enabled real time interventions preventing risks such as stuck pipe, ensuring shoe-to-shoe drilling, and avoiding potentially lost-in-hole (LIH) costs. This monitoring process also enabled significant ILT reduction, saving approximately USD 500k for the three wells.
This case study demonstrates the use of a novel approach to increase well construction efficiency by eliminating lost time while enhancing risk control. The main basis for success of this workflow is using existing and cost-effective technology while capitalizing on the renewed synergy between different departments such as drilling, mud logging, and well operations analysis.
The workflow can be customized based on the different needs by combining specific modules for monitoring, analysis, and wellbore surveillance services to increase the efficiency of any well construction.
A New ICD/ICV Well Completion Design Optimizer and Well Management Logic for Full Field Reservoir Simulation with Multiple ICD/ICV wells
Authors: Li D. , Alobedli A. , Selvam B. , Azoug Y. , Obeta C. , Nguyen M. , Al-Shehhi B. H. 
Published: November 2017

Abstract
In the current practice, ICD/ICV design parameters (e.g., number of compartments, compartment size, number of nozzles, and nozzle sizes) are optimized by a manual trial-and-error approach that requires tens to hundreds of iterations. To make the design process efficient and effective, an automated optimizer is desired. In addition, as more and more ICD/ICV wells are completed, reservoir simulation faces a challenge on how to efficiently run full field models with multiple ICD/ICV wells. This paper presents a new automated ICD/ICV design optimizer and an efficient way to run full field reservoir simulation with hundreds of ICD/ICV wells.
The new optimizer uses oil recovery efficiency as its objective function. The optimizer works on injectors and producers separately. For injectors, the optimizer adjusts the packer locations, number of nozzles, and nozzle sizes to make the injection velocity along the wellbore as uniform as possible to ensure a uniform injection front. For producers, a five step optimization process is applied. Step 1 is to generate injected fluid flow travel times in 3D from injectors to producers and all major flow "highways" are identified. Step 2, the optimizer uses fluid travel times in a producer to automatically estimate number of compartments needed and adjust the compartment boundaries (packers) to match the "highways" identified, estimate number of nozzles needed and initial nozzle sizes to maximize oil production rate. No reservoir simulation is required in steps 1 and 2. Step 3 is to run a full field reservoir simulation with all design wells to tune and achieve the final nozzle sizes. Step 4 is to QC and analyze the results of all ICD/ICV wells and select all successful candidates for the final step, i.e., step 5 reconciliation of the designs with all other drilling/completion constraints. The optimizer is fully supported by the efficient well management logic which accurately and efficiently links ICDs/ICVs with reservoir simulation. Using the well management logic removes the needs of coupling between well simulation tools (e.g., NETool) and reservoir simulation software, and then makes full field simulations efficient.
The new optimizer and well management logic have been applied and demonstrated significant values in a giant oil field in UAE. Compared to the traditional one-well-at-a-time well design, the new optimizer optimizes multiple ICD/ICV design wells at a time and results in better and faster designs with speedups in a range of several factors to an order of magnitude. The optimization is global and within the context of full field model. Running 370 ICD/ICV wells with the well management logic for a multi-million-cell reservoir simulation model only slows down the full field simulation around 10%.
Slim-hole Straddle Packer Microfrac Testing and Tectonic Stress Calibration in UAE Carbonate Reservoirs
Authors: Franquet J. A. , Smith S. S. , Noordin F. B. 
Published: November 2017

Abstract
The development of Lower Cretaceous reservoirs in a mature field located 84 km southwest of Abu Dhabi required a series of stress measurements across the reservoirs to tectonically calibrate the 3D Geomechanical model. The stress measurements were acquired by multiple straddle packer microfrac tests conducted through pipe-conveyance in a slim openhole wellbore. Various pore pressure depletion conditions across the reservoirs make the deployment of straddle packer tools in slimholes a very challenging operation.
Five in-situ stress measurements are acquired in this study from the proper identification of fracture closure pressure after reaching the formation breakdown pressure. Each microfrac test consists of three pressurization cycles and three pressure decline (fall-off) periods after fracture propagation. The fracture closure identification is achieved using three different pressure decline analysis methods on each fall-off test: (i) square-root of time, (ii) G-function and (iii) Log-Log plot. The final fracture closure measurement is obtained after consolidating the three fracture closure identification results in all three injection cycles conducted on each microfrac station.
The Microfrac tests conducted in the vertical pilot borehole provide precise in-situ measurements of formation breakdown, fracture reopening, propagation and closure at multiple reservoir layers. These in-situ measurements provide an accurate present-day stress profile across the reservoirs for constructing a proper 3D geomechanical model of the field. These microfrac tests measure minimum horizontal stress gradients of approximately 0.66 to 0.76 psi/ft, confirming the normal faulting stress regime in these reservoirs. The tectonic stress calibration is obtained by adjusting the value of tectonic strains across the reservoirs until the log-derived minimum horizontal stress matches the fracture closure pressure from the microfrac tests.
These in-situ stress measurements provide the subsurface information required to fully calibrate the tectonic stress acting on the reservoirs. This tectonic stress calibration is needed to create a representative 3D geomechanical subsurface model to predict accurate subsurface responses to stress and fluid flow over the field development. Additionally, conducting microfrac tests in slimholes provides multiple acquisition benefits: the straddle packer tool tolerates higher differential pressure across the elements than in large borehole, achieving higher absolute bottom hole pressure to induce formation breakdown; the borehole induced stress zone is radially smaller compared to larger hole sizes; the induced fracture does not required excessive propagation away from the borehole in order to capture the far-field in-situ closure stress.
Safer, Faster and Efficient Operations Through Operation Offline Stand Building: A Case Study
Authors: Belbaraka Chaima , Abd Elnaby Osama 
Published: November 2017

Abstract
Drilling industry is renowned to be one of the dangerous occupations with numerous catastrophic incidents that lead to significant fatalities, loss of assets, and impaired corporate reputations and businesses. There have however been significant strides in recent years after the 2010’s Gulf oil spill event, to improve operational efficiency and personnel safety. In response to the stringent safety protocols and industry’s increasing focus on operational safety and efficiency, significant improvements have been made in towards mechanization of pipe handling operations. These advancements have tackled some of the most laborious and imperative drilling operations; namely, pipe handling, tripping and making connections. This paper will describe in detail the adaptation of offline stand building system on island rigs fleet as a mitigation measure towards some HSE incidents from pipe handling habits of rig crew. The adaptation will illustrate a comparative study that has been made to two vendors systems and criteria entailed to choose the best-fit system design in a case study.
Impact of Change in Reservoir Dynamics and ESP Installation on Subsea Pipeline System
Authors: Selvam Rajendran , Qambar Najem A , Shebli Adnan Al , Bufalah Salah Jebara , Ismail Jawed , Singh Devinder , Panambur Sandeep 
Published: November 2017

Abstract
It is a known fact that reservoir characteristics are never the same and have always been continuously evolving and changing either because of natural factors or due to sustained water and gas injection activities to meet the target production. Changes are not only observed in crude chemistry but also with regards to fundamental pressure, temperature and quantum of formation water, considered as among the most important and critical parameters affecting the design and layout of any surface facilities and subsea infrastructure such as existing and new pipeline networks including the downhole system. To meet and balance this ever-growing short term and long term demand for production, it has always been a common practice to install ESPs (Electrical Submersible Pumps) as it serves the intended purpose. Parametric studies have shown that drawing flow through ESPs have affected the integrity and life of existing infrastructure particularly "subsea pipeline network". Therefore, efforts have been made in this paper to highlight the extensive study that has been carried out in assessing the unprecedented damage caused to one of the subsea oil pipeline including capturing the business risk it has imposed. Further details of evaluation of several mitigation options have been presented trying to bringing down the corrosion but also actions taken towards securing a permanent long term solution.