bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Proppant Designed to Decrease Water Production
Authors: Green John , Dewendt Andreina , Terracina John , Abrams Benjamin , Harper Adam 
Published: October 2018

Abstract
This paper discusses research on how proppant selection affects fracturing treatment results in shale formations that produce high water volumes. Fracturing treatments, formation characteristics, proppant types, and post fracture treatment production results are examined in detail. A production case study that focuses on the impact of proppant selection in wells completed in formations that produce hydrocarbons with a high water cut will also be presented.
This paper analyzes laboratory tests that were performed to measure the water and oil flow rates of various commonly used proppants. A case study on how Decreased Water Flow Proppant (DWFP) performed in the Granite Wash in the Texas panhandle is also highlighted. Post fracture treatment production results are compared to traditional proppants used in direct offset wells.
Laboratory testing showed DWFP had much lower water flow and higher oil flow through the proppant pack compared to traditional proppants. The results of the laboratory tests will be used to explain and support the production case study. The field case study proves that DWFP reduced formation water production, while increasing hydrocarbon production compared to traditional proppants used in offset wells. This innovative proppant appears to decrease the relative permeability to water in the proppant pack, resulting in lower water production and higher hydrocarbon production compared to conventional proppants.
This paper introduces the first proppant specifically designed for fracturing treatments in high water cut reservoirs. A new laboratory test method of measuring water flow rate through a proppant pack was specifically developed for this type of proppant. The proppant’s wettability is introduced as a new proppant selection factor for fracturing treatments in high water cut reservoirs.
Experimental Investigation of the Effect of Pore Size on Saturation Pressure for Gas Mixtures
Authors: Salahshoor Shadi , Fahes Mashhad 
Published: October 2018

Abstract
Accurate determination of the dew point pressure of gas condensates in nano-porous ultra-low permeability reservoirs is crucial to prevent liquid dropout inside the formation. This paper presents a proof of concept experimental data and procedure to explain the effect of the pore size distribution on the degree and direction of the shift in the saturation pressure of gas mixtures under confinement compared to the bulk behavior.
We built a packed bed of BaTiO3 nanoparticles, providing a homogenous porous medium with pores of 5 to 50 nm, providing a volume more than 1000 times larger than typical nano channels. We designed an isochoric apparatus to monitor pressure for a fixed volume of fluid under confinement and bulk conditions simultaneously. A binary mixture of ethane-pentane undergoes an isochoric process with pressures of 10 to 1500 psi and temperatures of 290 to 425 K. The result is a set of Isochoric lines for the bulk and confined sample, plotted on the phase envelope to demonstrate the change in saturation pressure.
Many attempts in explaining the shift in saturation pressures of the reservoir fluid confined in the narrow pores of unconventional reservoirs compared to those of the bulk can be found in the literature. However, there are some contradiction between the predicted behavior using different mathematical approaches. Experimental data could be substantially helpful in both validating models and improving the understanding of the fluid behavior in these formations. Contrary to what many published models predict, our results show that confinement effects shift the dew point pressure towards higher values compared to the bulk for a fixed temperature in the retrograde region. In the non-retrograde region, however, this shift is towards lower dew point pressure values for the confined fluid compared to the bulk. Capillary condensation is assumed to be the main source of the deviations observed in the behavior of fluids inside nanopores. We evaluate published models, including those based on EOS modifications, by comparing it to experimental results to provide a quantification of their accuracy in predicting saturation pressure values for confined mixture.
This paper provides an alternative approach to examine the effect of pore size on phase behavior over a decent and practical range of pressures and temperatures. The synthesized porous medium is very helpful in uncoupling the effect of pore size from the effect of mineralogy on the observed deviations in behavior. Experimental findings are valuable for validating existing theories and can be used to adjust proposed mathematical approaches towards better predictions of saturation pressures for other systems.
Using MPD Techniques for Lower Completion Replacement: Unleashing a Powerful New Solution for Challenging Workover Interventions
Authors: Schnitzler Eduardo , Alonso Fernandes André , Savoldi Roman Roger , Pereira da Silva Paulo Henrique , Medina Ascaneo Willian , Storani de Almeida Renato , Bolfarini Harami Guilherme 
Published: October 2018

Abstract
This paper describes how Managed Pressure Drilling (MPD) techniques can be used in some workover and completion operations, such as the lower completion replacement. It also presents the first application of this kind of solution in a subsea well, which has been recently done in Lula field in the Brazilian pre-salt.
Highly stimulated wells in the Brazilian pre-salt carbonate reservoirs set significant challenges for well engineers when the lower completion must be replaced in workover operations. Major fluid losses are expected as the formation cannot be isolated from the wellbore. Costly loss control operations must be performed prior to the completion retrieval, introducing LCM in the well, causing formation damage and requiring further well cleaning and stimulation. A new approach was developed, in which MPD techniques such as Mud Cap Drilling (MCD) are used to cope with the fluid losses and avoid loss control operations and its associated impacts while maintaining a safe operation.
The use of two of the MPD techniques, Pressurized and Floating Mud Cap Drilling (PMCD and FMCD), in the scenario previously described allow the use of sacrifice fluid, usually treated seawater, to continuously inject underbalance or overbalance fluid into the well and avoid hydrocarbons migration during operations with highly stimulated formations still connected to the well. This also allows monitoring the well for any well control issue, as well as applying well control procedures. Even in the FMCD technique a Rotating Control Device (RCD) is used below the drilling riser slip joint to prevent any possible gas migrated into the riser to reach the rotary table.
The use of this kind of solution has turned the lower completion retrieval or replacement an operation with less deviation in terms of duration and budget. Costly loss control operations are avoided and there is no need to introduce loss control materials into the well, which could lead to problems when retrieving or installing the lower completion, such as stuck pipe or equipment failure. The customization of MPD techniques and the development of specific procedures for completion and workover with MPD have led to safe and more efficient operations in challenging subsea interventions with DP rigs.
This new approach has set an alternative workover philosophy for some pre-salt wells and also opened new opportunities worldwide by the application of this innovative solution. A significant amount of wells equipped with intelligent completion in pre-salt areas do not have a separated completion that could temporarily isolate the formation during heavy workover interventions. In this scenario the use of MPD techniques like presented in this paper might be a valuable solution.
Efficient Simulation of Two-Phase Compositional Flow in Fractured Reservoirs Using 3D Unstructured Gridding in Complex Geometries
Authors: Zidane Ali , Firoozabadi Abbas 
Published: October 2018

Abstract
We present a higher-order numerical model for compositional two-phase flow in fractured media in 2D and in 3D unstructured gridding. The model accommodates all types of finite elements; in particular, quadrangular and triangular elements in 2D, and hexahedra, prisms and tetrahedra elements in 3D.
We apply for the first time the fracture cross-flow equilibrium (FCFE) concept in compositional two-phase flow in 3D. FCFE is combined with the hybridized form of the mass conservative mixed finite element (MFE) and the higher-order discontinuous Galerkin (DG) method. We have developed an interface that connects computer-aided-design (CAD) software to the mesh generator. The interface enables us to generate the most complicated fracture shapes. The application is intended for fracking simulation. To the best of our knowledge the complexity of fractures that we generate/simulate is not reported in the past. Our algorithm allows flow simulation in fractures in all range of permeability values as opposed to other models where low permeable fractures affect the accuracy of the results. We demonstrate the efficiency, accuracy, and strengths of our model in comparison to alternatives including the embedded discrete fracture approach in different examples. This work covers generation and simulation of two-phase compositional flow in complex fractured media in 3D unstructured gridding.
Automating Directional Drilling: Technology Adoption Staircase Mapping Levels of Human Interaction
Authors: Wylie Robert , McClard Kevin , de Wardt John 
Published: October 2018

Abstract
Good directional drilling practices have a huge impact not only on drilling costs, but on improved reserves recovery, as well as on production costs such as submersible pump failures and pump rod wear. These are all helped by improving wellbore quality, lowering tortuosity, and more accurate well placement with increased percentage of the wellbore in the target zone. The very high rates of penetration being achieved today in build and hold sections require the processing and action speed of automation to supplement the directional driller’s ability to achieve these goals. In addition, there are widespread industry drives to reduce personnel at the rig site, and to automate drilling systems.
A Levels of Automation Taxonomy (LOAT) was introduced by the Drilling Systems Automation (DSA) Roadmap initiative (SPE 178841). The DSA LOAT is based on incremental automation of the four cognitive functions of interaction, which are Information Acquisition, Information Analysis, Decision Making and Action Selection, and Action Implementation. Levels of human to systems interaction are described on a nine-point scale ranging from fully manual, through levels of system support for the human, through levels of automation overseen by the human, to full automation.
Directional Drilling Automation systems are being progressively accepted by the drilling industry. This paper describes those systems’ progress along the cognitive functions and levels of automation defined by the LOAT. It highlights the usefulness of the LOAT to help users understand their current levels, provide a path forward, and manage expectations of potential users. Successful automation is neither an all or nothing proposition, but rather a progression to increasing levels of each cognitive function that balance desired goals for automation against the risks and uncertainties requiring human consideration. Best practices in wellbore placement are being adopted as automation is advanced; the value being demonstrated by automated directional drilling requires suppliers to implement and manage all necessary data flows on a consistent and reliable basis.Appropriate automation systems can improve cross-functional communications, increase organizational efficiency, and enhance geosteering involvement for timely target revisions and improved reservoir exposure.Automated Decision Making can improve consistency between individual directional drillers, wells, and of delivery of best practices developed by individual companies.Higher levels of automation require the involvement of Rig Control System builders, and increased acceptance and implementation of the automated decisions.
Automation should not be seen as an end goal in itself, but a means to add value through appropriate application. In the case of automating directional drilling, value is being added through reduced HSE impact and overall cost efficiencies such as reduced dollars per foot and reduced dollars per barrel.
Numerical Simulation of EOR from Wettability Alteration in Tight Oil Reservoir with Multiple Hydraulic Fractures
Authors: Jung Hye Young , Onishi Tsubasa , Datta-Gupta Akhil 
Published: October 2018

Abstract
The focus of this paper is the application of colloidal suspensions of nanoparticles, commonly known as "nanofluids" for enhanced oil recovery in tight oil reservoirs. Nanofluids are specialized colloidal solvents, compatible with various types of fluids used in oil reservoirs and they have the potential to enhance the recovery of oil and gas from a variety of rock pores (EOR). Nanofluids can be used as an important tool to alter the properties of the formations. We examine here the underlying mechanisms, including the wettability alterations and reduction of the interfacial tension driving enhanced oil recovery in tight oil reservoirs using compositional numerical simulation.
We start with a review of the nanofluid properties critical to mobilize oil in the reservoir pore network by wettability alteration. We then demonstrate the effectiveness of surfactant-based nanofluids for wettability alteration using a comprehensive chemical flooding simulation. The modeling of wettability modification depends on a shift in relative permeability and capillary pressure curves during simulation. Altered wettability affects the residual phase saturations which, in turn, influences the relative permeability and causes oil mobilization. Moreover, capillary imbibition promotes oil recovery as the wettability is altered towards water-wet conditions. We investigate the major factors in wettability modification and how they influence the oil recovery through exhaustive sensitivity studies and a Pareto-based multi-objective optimization approach.
This study concentrates on the nanofluids mechanisms in enhanced oil recovery, including the permeability alterations, rock wettability alterations and reduction of the interfacial tension. A comprehensive simulation sensitivity study and a multi-objective optimization approach are utilized to identify the dominant parameters impacting oil recovery in tight oil reservoirs using complex surfactant based nanofluids. Based on the results, a set of guidelines are suggested for selection and application of nanofluids for improving oil recovery in tight oil reservoirs stimulated with multiple hydraulic fractures.
Utilizing a Data Analytics Workflow to Optimize Completion Practices While Leveraging Public Data: A Permian Basin Case Study
Authors: Olaoye Olubiyi , Zakhour Nancy 
Published: October 2018

Abstract
An evidence based hydraulic fracturing and production optimization procedure is presented using modern data science and data analysis techniques by leveraging publicly available data from the Midland and Delaware basins of the Permian. Results show a point of diminishing return has either been crossed or is being approached as Exploration and Production companies have intensified completions designs by tightening stage lengths, increasing number of clusters, increasing lateral lengths and more importantly escalating proppant and water volumes.
Multiple public data sources including FracFocus Chemical Disclosure Registry and the Texas Railroad Commission are combined, cleaned and processed for analysis with a unique workflow to showcase design optimization. Three critical completion parameters: proppant volume, lateral length and proppant loading have been addressed for select counties in the Midland and Delaware Basins of West Texas. The relationships between these three parameters and other variables affecting well performance are investigated and normalized using multivariate statistics techniques. These topics can directly help operators leverage data science methodologies to use historical data for data driven decisions that assist in optimizing completion designs while generating sound well economics.
This paper focuses on more recent completion designs (2013 onwards) where hydrocarbon production information reported is statistically significant while simultaneously focusing on the more relevant completion design solutions driving the ongoing shale revolution. In general, increasing proppant loading improves well performance, however the relationship is nonlinear, and operators need to be cognizant of the degree of nonlinearity associated with proppant volumes, potentially size and type. The approach described and presented here tackles the Midland and Delaware Basin of West Texas and can be applied to other basins as the data used is available and public.
This paper discusses a method that maximizes the use of public information while drilling down to specific completion parameters to assist in data-based decisions. The techniques used can be expanded to implement artificial learning in asset development.
Auto-Driller Automatic Tuning
Authors: Badgwell Thomas , Pastusek Paul , Kumaran Krishnan 
Published: October 2018

Abstract
While drilling rig control systems have been deployed for many years, a 2016 study [1] identified significant room for improvement in three areas: auto-drillers, top drive torsional damping systems, and heave compensation systems. In particular, in a representative configuration the auto-driller Weight-On-Bit (WOB) controller can exhibit undesirable behavior, including instability, as the drill bit penetrates successive layers of rock with differing hardness. An unstable WOB controller may lead to inefficient drilling and bit damage, and can even induce stick-slip. It was shown, both by simulation and by tests on actual wells, that this behavior can be mitigated by appropriate adjustments to the WOB controller gain. In this paper we present a new algorithm, which we call Drilling Rig Automatic Control Tuning (DRCAT), designed to make these controller gain adjustments automatically. We challenge the auto-driller vendor community to either deploy the DRCAT algorithm or develop a better solution.
Deployment of a Novel Proppant Coating Technology for Controlling Airborne Dust in the Permian: A Case Study
Authors: Kakadjian Sarkis , Reynolds Michael , Sawyer Jordan , Kelly Patrick , Bammidi Vidya , Murray Dennis , Solomon Marvin 
Published: October 2018

Abstract
Occupational exposure to respirable silica from proppant sand is a risk to field personnel in oil and gas operations. This risk must be mitigated to comply with new OSHA regulations that will take place between 2018 and 2021 for limiting respirable crystalline silica to less than 50 micrograms per liter averaged over across an 8-hr period. Therefore, oil and gas operators, oilfield service companies, and proppant suppliers are poised to employ technologies that can address proppant dust control in the field.
Historically, engineering controls have been applied to reduce sand dust using vacuum systems to gather dust in central locations; while other mechanical approaches include limiting sand volumes on conveyer belts or storing sand in silos (necessitating use of a trailer and a storage bin). This paper discusses laboratory and field results from tests designed to mitigate dust that results from handling sand during hydraulic fracturing operations. Coating proppant sand with inert chemical solutions that include a 100% environmentally-friendlybenign chemical blend at transloading rail facilities will be described.
Experimental test results to be discussed include lab scale screening of 10+ aqueous and nonaqueous formulations to control dust, sand caking studies, sand flowability, changes in conductivity, bacterial control testing, and chemical compatibility testing with current additive packages used in slickwater and crosslinked gel systems.
The outcome of field applications using coated sand samples in the Permian Basin showed up to a 97% decrease of dust generated and levels of employee exposure to respirable crystalline silica less than the revised OSHA PEL of 50 μg/m3 as measured in 10-mm nylon Dorr-Oliver cyclones.
A long-term goal for this product is to eliminate the risk of respirable crystalline silica even less than the OSHA action levels at 25 μg/m3 to field staff and to reduce dust exposure to the equipment, improving safety and operational efficiency for operators.
Back to Basics: Revisiting Proppant and Fluid Selection for Unconventional Reservoirs Using a New 2D Slurry Transport Model
Authors: Pankaj Piyush , Belyakova Ludmila , Isaev Vadim , Velikanov Ivan , Bannikov Denis , Semin Leonid , Tikhonov Alexey 
Published: October 2018

Abstract
It is often thought that in ultra-low-permeability unconventional reservoirs, proppant does not play a significant role in productivity because any proppant effectively results in a relatively infinite fracture conductivity. Although with over 75% of the treatment jobs pumped with slickwater in the shale reservoirs due to its cost benefit, it is also thought that slickwater has limited solids carrying capacity. Overflushing may compromise productivity by creating near-wellbore pinchouts. The study presented here aims to test some of these conventions through the use a new high-resolution slurry transport model in unconventional reservoirs. Hydraulic fracture propagation and solids transport are simulated across multiple wells and reservoir settings to measure the production performance of unconventional reservoirs.
Wells completed in the Eagle Ford formation are studied using an integrated earth model built to capture the reservoir geology, petrophysics and geomechanics. A pseudo 3D model for fracture propagation has been coupled with a fine grid numerical simulation of proppant and fluid transport in hydraulic fracture. The transport model can distinguish and demarcate the corresponding bridging resolution. This allows capturing the effect of slurry with proppant bypassing bridged 2D elements.
Multivariate analysis of over 50 cases with various combinations of hydraulic fracturing fluid with viscosity ranging from 1.5 cP (slickwater) to 362 cP (crosslinked gel) and various proppants ranging from 100 mesh to 20/40 proppants are evaluated using the 2D transport model to determine the impact on production. Additionally, various pumping schedules ranging from 750 lbm/ft to 3,000 lbm/ft are evaluated. Parametric sensitivity of the overflush fluid type and volume has been studied to measure the impact on proppant dislodgement in the near-wellbore area. Production performance for all the scenarios is studied through numerical simulation and an economic analysis workflow to evaluate the matrix for fracturing fluid and proppant selection.