bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Heterogeneity of Layered Reservoirs on Polymer Flooding: An Experimental Approach Using 5- Spot Glass Micromodel
Authors: Emami Meybodi H. , Kharrat R. , Ghazanfari M. H. 
Published: June 2014

Abstract
Despite the numerous experimental studies, there is a lack of fundamental understanding about how the local and global heterogeneity control the efficiency of polymer flooding. In this work a series of water and polymer injection processes are performed on five-spot glass micromodels which are initially saturated with the crude oil at varying conditions of flow rate, water salinity, polymer type and concentration. Three different pore structures in combine with different layer orientations are considered for designing of five different micromodel patterns. It has been observed that the oil recovery of water flooding is increasing with the salinity concentration, for the ranges studied here. While, it shows there is an optimum value of concentration in which maximize the oil recovery in polymer flooding. The results confirmed that the highest oil recovery is obtained when the layers are perpendicular to the mean flow direction for both water and polymer flooding. Also, the oil recovery in polymer flooding increases with the increase of layer inclination angle, however it does not increase for waterflooding. In addition, the oil recovery is strongly affected by the local heterogeneity which is near injection zone. This study demonstrates the applicability of micromodel for studying of enhanced oil recovery techniques in locally and globally heterogeneous five-spot models.
A New 3-D Numerical Model to Effectively Simulate Injection Tests
Authors: Verga F. , Viberti D. , Borello E. Salina 
Published: June 2014

Abstract
Conventional well testing is becoming less and less attractive due to environmental constraints and high costs. It is likely that injection/fall-off tests will largely replace the conventional production/build-up sequence since they eliminate surface emissions and can significantly reduce testing costs. However, the welltest interpretation is complicated because of the presence of two phases, the fluid originally in place (hydrocarbon) and the injected fluid (diesel or brine). Fluid saturations vary during injection and the assumption of a piston like displacement is valid only for very favourable mobility ratios. Thus the variation of fluids distribution with time is governed by effective permeabilities, but also gravitational and thermal gradients, heterogeneity and anisotropy might strongly affect the flow. As a consequence, the conventional analytical approach used to describe the pressure transient behaviour is no longer applicable, and only numerical simulations can thoroughly describe the evolution of saturation and pressure fields in the reservoir during injection and subsequent fall-off. The correct determination of the fluid distribution is critical for evaluating the skin due to the presence of two phases in the reservoir, and in turn the skin value, together with permeability, is essential to calculate the well productivity.
A new near wellbore, 3D numerical model was developed and implemented for properly designing and interpreting injection tests in both oil and gas reservoirs. The model accounts for all the aspects that can impact on fluid and pressure distribution. The simulation results are provided in terms of pressure and pressure derivative for subsequent analyses. The reliability of the results were verified against commercial well testing software packages under simplified conditions, i.e. isotropic and homogeneous formation, negligible gravitational, capillary and thermal effects. The advanced options of the model were then applied to simulate injection tests with thermal exchange between fluids in oil and gas reservoirs. The results are presented in this paper.
Pore Network Modeling of Two Phase Flow in Vuggy Carbonates
Authors: Akin S. , Erzeybek S. 
Published: June 2014

Abstract
Carbonate reservoirs have more complex structures than silicate reservoirs because of depositional and diagenetic features. Secondary porosity enhancements due to fracturing or dissolution processes result complex porosity systems and thus complex flow patterns. Carbonates may contain not only matrix and fracture but also the vugs and cavities that are irregular in shape and vary in size from millimeters to centimeters in diameter. Although many of these vugs appear to be isolated from fractures, the mechanism of oil recovery from vugs in such a system is highly dependent on the location of the vugs and connections of the vugs to the matrix.
Studies on pore network models of carbonate rocks available in literature generally consider regular grain lattices, disregarding secondary porosity features. In this study, two phase flow in vuggy carbonates was studied by developing a novel pore network model. The constructed model consists of matrix and vug sub-networks. Matrix blocks were constructed by pores with triangular cross-section and pore throats with circular cross-section where as vugs were represented by square cross-sections. By distributing pore and pore throat radii randomly, a spatially uncorrelated model was developed. It was observed that this model can successfully simulate primary drainage and secondary imbibition recovery processes like snap-off, piston like advance and pore body filling. Comparison of pore network results and several published experimental results showed the uses and applications of the proposed pore network model. It was concluded that this novel pore network model design successfully represents two phase flow in a vuggy carbonate rock.
Matrix-Fracture Transfer Function in Dual-Medium Flow Simulation: Review, Comparison, and Validation
Authors: Abushaikha Ahmad S. A. , Gosselin Olivier R. 
Published: June 2014

Abstract
Most of porous naturally fractured reservoirs present a two-timescale flow-system, due to a two-scale heterogeneity which cannot be modelled explicitly, nor homogenised in reservoir simulation models. When the only flowing domain is the fracture network, and when the accumulation lies in porous and low permeable matrix blocks, the rate of exchanges between the two domains drives the recovery of such reservoirs. So called dual-porosity simulation models must incorporate an adequate transfer function between fracture and matrix in order to predict the recovery mechanisms for an optimal reservoir management. This is still true for dual-porosity / dual-permeability models, where the matrix domain is also flowing but at lower velocity.
During the past 40 years until recently several formulations have been proposed. In order to review, compare and validate some of them, this work first analyse the main recovery drivers in two-phase systems, like drainage and imbibition under capillary and gravity forces, on the basis of explicit (single-porosity) simulations of flows between fracture and a single matrix block on a fine mesh, characterised by the final value and the kinetics of the recovery. Varying the main dynamic parameters these simulations give a set of reference cases to benchmark the dual-medium models, like the classic Kazemi transfer function, the Quandalle-Sabathier one, and a new formulation recently proposed by Blunt et al. These dual porosity single-block transfer functions are easily discretised in time and coded.
The main findings are the disqualification of Kazemi formula, even with a gravity term, to represent any mechanism where the gravity is not negligible, especially in mixed-wet water-oil systems. Quandalle-Sabathier and Blunt transfer functions perform better, but the gravity forces remain difficult to be captured. The two first transfer functions are available in some commercial flow simulators, and their results on the same set of cases are consistent.
Distributed Unstructured Grid Infrastructure for Complex Reservoir Simulation
Authors: Fung Larry S. K. , Dogru Ali H. 
Published: June 2014

Abstract
It is now standard practice to use reservoir simulation as an everyday tool for better engineering and management of oil and gas fields. Modern reservoir simulation must be comprehensive in the treatment of complex reservoir processes, complex geology, intelligent maximum reservoir contact (MRC) wells, and production systems. For the more mature giant oil fields, significant volumes of detailed data are available. It is critical to maximize the use of these data for field planning in order to optimize recovery. Nowadays fast inexpensive parallel computers are widely available, modern reservoir simulators can exploit parallelism effectively such that modeling can be done at the desired scale and speed for better and timelier reservoir management. Simulators must also have the flexibility to use the general structured or unstructured grid systems for any combination of complex geology and recovery processes.
To handle all these complexities in a massively parallel environment, we have developed in Saudi Aramco's in-house reservoir simulator POWERS a distributed unstructured grid infrastructure (DUGI). DUGI is the parallel data structure and algorithms which constitutes the simulator's nerve center. Typical complex models for giant fields can have tens to hundreds of millions of grid cells, handling hundreds to thousands of wells, including some complex MRC wells. It can contain geologic features such as faults, pinch-outs, and fracture and multimodal porosities, described as the multiple porosity multiple permeability (MPMP) system. Both structured grids, with irregular multilevel local grid refinements (LGR) and unstructured grids can be used to resolve local reservoir or well geometry, and to model dynamic near-well coning behaviors. DUGI unifies the management of all these complexities into a consistent, scalable, and extendable system. It is designed to be modular such that data complexity and communication management are hidden from the rest of the simulator. This enhances simulator extensibility for ongoing feature development. Elements of DUGI will be discussed and examples of simulation models and results provided.
Advanced Engineered Fiber Technology - A Novel Solution to Cure Lost Circulation During Drilling: Pakistan Case History
Authors: Priening Peter , Ali Muhammad , Jaffery Maimoon , Salazar Jose , Jain Bipin 
Published: June 2014

Abstract
Losses while drilling are a serious concern to oilfield industry. Loss of expensive drilling fluid increases the overall cost of the well. Rig time spent curing the losses can represent significant cost overruns for the well. In extreme cases well control may become an issue.
The general practice to control losses starts from diagnosis of the cause. The common solutions to manage the loss circulation problem include drilling fluid treatments involving decreasing the density, controlling the viscosity and addition of lost circulation materials (LCM), controlling the drilling parameters, and placement of cement plugs.
This paper will discuss the treatment of drilling fluid with Advanced Engineered Fiber (AEF), the mechanism of action of AEF and its successful application as a solution for lost circulation in Pakistan.
Applications of Rotary Steerable in Low Cost Environments
Authors: Riyami M. , Edwards J. , Vache E. , Ojeiduma O. , Darwish W. , Johnston S. 
Published: June 2014

Abstract
The hydrocarbon basins in the Sultanate of Oman are in the desert where rig rates are low. This is not the typical environment for sophisticated drilling systems such as rotary steerables. However there are a number of niche applications where the use of this technology makes business sense. This paper will describe each application, explaining how a particular problem was solved with the use of rotary steering. Some of these applications are more unusual than others. For example one application is efficient directional drilling in hard abrasive layered formations of S-shape and J-shape profiles. Another is drilling buildups to precise horizontal landing depths, or drilling absolutely vertical holes in wells that have long heavy-wall liner sections that are run with inner strings and mechanical-set liner hanger packers. The consequence of a dog leg has been a liner that would not go down, but too heavy to retrieve. The rotary steerable applications also include assisting the acquisition of geological data. For example drilling extended reach smooth boreholes in fractured carbonate so they can be logged with imaging tools conveyed on drill pipe that can not be rotated. The measure of success, and a large part of the remuneration, is based on the imaged meterage not drilled meterage. These wells were drilled with an inclination-hold feature that kept the trajectory as straight as possible. Another geological example is the use of rotary steerables to accompany an azimuthal deep reading measurement used to geosteer the well. The elimination of sliding removed the blind zones that are a consequence of azimuthal logs, and the near-bit inclination helped the directional driller avoid over steering when the geosteering team requested an inclination change.
Utilizing Infrared Meters to Cost Effectively Monitor Water Cut on Horizontal Wells
Authors: Al-Saiyed Muhammad A. , Warsi Syed A. , Phillips James E. , Lievois John 
Published: June 2014

Abstract
The success of field monitoring and management depends on the accuracy and precision of the data gathering quality. A major parameter is the water cut value. The range of methods to measure and obtain the water cut values varies from conventional to high technical. Providing a means for continuous monitoring provides the information to take corrective action in a timely manner to better manage expensive well assets by maintaining well potential, managing water conformance and increasing the well life.
Saudi Aramco's traditional well testing practices, utilizing a test trap at a GOSP, limit the information available due to the frequency of test trap availability on a per well basis. This usually exceeds one month or more. Test trap data has inherent error built in due to averaging and human error. However, high tech real time water cut monitoring systems can provide the needed frequency and precision. Choosing the right application depends on how much data is needed and how accurate the data can be. In considering the methodology for obtaining water cut data, accuracy, data transference and cost play major roles.
Needless to mention, the drilling cost is significantly high when it comes to high potential complex multilateral and MRC wells. The expenditure for such wells can not be recovered if the wells die due to high water cut that goes unnoticed due to lack of data. Real time water cut monitoring can significantly reduce the number of such dead wells by providing the data to implement corrective action in a timely manner. This paper presents that how the infrared meter provides cost effective mean to monitor water cut for expensive complex wells.
An Integrated, Innovative Solution to Optimize Hydrocarbon Production Through the use of a Workflow Oriented Approach
Authors: Gutierrez F. , Bouleau C. , Howell A. , Gehin H. 
Published: June 2014

Abstract
Today's hydrocarbon environment requires depth of knowledge and expertise combined with technology innovation and integration across the various disciplines involved in the Reservoir Management cycles going from exploration to production, in order to increase production, reserves and improve operational efficiency.
An integrated approach including People, Process and Technology is necessary to break the barriers between the various reservoir management cycles - operations - production optimization and field management, and to improve the maturity of information to knowledge. Engineering processes related to each reservoir management cycle need to be accelerated by the implementation of automated/ & interactive workflows, integrating various levels of field data frequency with petrotechnical processes, that can help in operational efficiency, leaving more time for a more proactive engineering analysis of problems and solutions. A successful workflow approach ensures that the hydrocarbon's decline curve is mitigated with higher ultimate recovery. Also, the integration of data with numerical and analytical reservoir and well models, through workflows, helps to bring more efficiency in the field planning cycle in order to establish proper Enhanced Oil Recovery (EOR) or in-fill drilling plans to increase recovery factors.
The purpose of this paper is to show how workflow oriented solutions, within the context of the Digital Oilfield, have helped increase production, ultimate recovery factors and operational efficiency in various types of operational environments, and i.e. water flooding, Water Alternating Gas (WAG) and gas lifted fields.
Probabilistic Subsurface Forecasting - What Do We Really Know?
Authors: Wolff Martin 
Published: June 2014

Distinguished Author Series articles are general, descriptive representations that summarize the state of the art in an area of technology by describing recent developments for readers who are not specialists in the topics discussed. Written by individuals recognized as experts in the area, these articles provide key references to more definitive work and present specific details only to illustrate the technology. Purpose: to inform the general readership of recent advances in various areas of petroleum engineering.
The full manuscript of SPE 132957, ’Probabilistic Subsurface Forecasting,’ is available as a supplement to this article.
Abstract
The use of single-valued assessments of company portfolios and projects continues to decline as the industry accepts that strong subsurface uncertainties dictate an ongoing consideration of ranges of outcomes. Exploration has pioneered the use of probabilistic prospect assessments as being the norm, in both majors and independents. Production has lagged, in part because of the need to comply with US Security and Exchange (SEC) reserves-reporting requirements that drive a conservative deterministic approach.
Look-backs continue to show the difficulty of achieving a forecast within an uncertainty band as well as the difficulty of establishing what that band should be. Ongoing challenges include identifying relevant static and dynamic uncertainties, efficiently and reliably determining ranges and dependencies for those uncertainties, incorporating production history (brownfield assessments), and coupling subsurface with operational and economic uncertainties.
Despite these challenges, none of which are fully resolved, a systematic approach based on probabilistic principles [often including design-of-experiment (DoE) techniques] provides the best auditable and justifiable means of forecasting projects and presenting decision makers with a suitable range of outcomes to consider.
Introduction
Probabilistic subsurface assessments are the norm within the exploration side of the oil and gas industry, both in majors and independents (Rose 2007). However, in many companies, the production side is still in transition from single-valued deterministic assessments, sometimes carried out with ad-hoc sensitivity studies, to more-rigorous probabilistic assessments with an auditable trail of assumptions and a statistical underpinning. Reflecting these changes in practices and technology, recently revised SEC rules for reserves reporting (effective 1 January 2010) allow for the use of both probabilistic and deterministic methods in addition to allowing reporting of reserves categories other than ’proved.?? This paper attempts to present some of the challenges facing probabilistic assessments and present some practical considerations to carry out the assessments effectively.
Increasing Oil Field Productivity Work Processes / Workflows in Digital Oil Fields
Authors: Pande Anil 
Published: June 2014

Abstract
As has already happened with most other industries in the past decade, the use of workflows in the E&P industry has only recently become increasingly prevalent. However, the way workflows are used in actual production operations is fundamentally different from other industries. The benefits of workflow in the E&P industry can lead to increased production and lower operating costs, and better use of scarce manpower resources, as discussed in the paper.
For workflows to be used in the E&P industry there are many important dependencies that must already be in place, based on the life of the asset as well as its maturity level. These range from process automation, data sources, and integration amongst others. In order to implementation a workflow within E&P, the steps needed to create and validate the workflow, taking an example such as production surveillance is covered.
Drill String Vibration Mitigation During Simultaneous Drilling and Hole Enlargement
Authors: Mancini Stefano , Hitchcock Graham , Opsahl Jørn , Servaes Luk 
Published: June 2014

Abstract
Drill string vibrations (torsional, axial, and lateral uncontrolled movements) can create issues with equipment, drilling performance and wellbore quality. With respect to equipment, prolonged excessive drill string vibration exposure can lead to fatigue failure such as drill string ‘twist off’, downhole tool breakage, shorter mean time between failure (MTBF) for measurement-while-drilling (MWD)/logging-while-drilling (LWD), and, in general, for directional drilling components. In rotary steerable drilling, a moderate to high drill string vibration can result in poor directional control, reduced penetration rate, and loss of time. This can result from reactive changes in drilling parameters intended to reduce detected drill string vibrations. Wellbore quality can suffer if the vibrations cause the bit to not drill a smooth borehole.
Simultaneous drilling and hole enlargement are sometimes associated with drill string vibration because of complex bottomhole assembly (BHA) dynamics involved in creating two hole sizes. Sources of drill string vibration during hole enlargement can be the drill bit, hole enlargement tool, or BHA. Mitigation of drill string vibration with respect to hole enlargement tools is of major interest because this can lead to reduced drilling costs, longer tool life, and improved wellbore quality.
This paper discusses specific expandable hole enlargement tool technologies that contribute to a reduction of vibration levels. Case history data is used to demonstrate these technologies, which have been shown to minimize drill string vibration during drilling and simultaneous enlargement operations, leading to the successful completion of well objectives.