bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydraulic Fracture Geometry Evaluation Using Proppant Detection: Experiences in Saudi Arabia
Authors: Bartko Kirk , Salim Ahmed , Saldungaray Pablo , Kalinin Daniel , Han Xiaogang , Saldungaray Pedro 
Published: September 2013

Abstract
Accurate determination of the propped fracture geometry compared to the stimulation design can help fine-tune geomechanical models and to optimize future hydraulic fracture treatments. Conventional methods to evaluate fracture height with logs use radioactive tracers pumped downhole together with the proppant. Subsequently, natural gamma ray spectroscopy logs are run to detect the tracers; however, safety and environmental concerns, together with regulations regarding transportation, storage and use of radioactive materials, can limit the use of these tracers.
Newly developed proppant techniques allow detection without the need of using radioactive elements. Special compounds coat the substrate or are mixed with the proppant material. These interact with neutron logs, making it possible to evaluate the propped fracture height, and in certain cases, have a qualitative idea of the fracture width. Two approaches used by major proppant manufacturers consist of: (a) compounds that are activated by a neutron source, and (b) compounds that absorb neutrons (high capture cross section) and can be detected using conventional compensated neutron logs (CNL) or pulsed neutron capture (PNC) tools. Both PNC and CNL have a shallow depth of investigation, only a few inches away from the borehole, and therefore they indicate the propped fracture height in the near-wellbore region providing a first estimate where the proppant is placed.
This paper will present the results of the neutron absorbing approach under challenging conditions in dual casing strings in wells located in the northern area of Saudi Arabia. The methodology applied uses a comparison of pre-fracture log count rates and post-fracture count rates, with reduced post-fracture count rates observed in zones containing proppant, using both CNLs and PNC tools. The experience has provided information about the sensitivity of each logging device and allowed the comparison to other methodologies (temperature logs) and the formulation of recommendations.
First Application of Limited Entry Multistage Matrix Acidizing in Saudi Arabia’s Deep Gas Development Program – A Case Study for Improved Acid Stimulation and Placement Techniques
Authors: Ahmed Mahbub , Habbtar Ali , Al-Malki Bandar , Rahim Zillur , Al-Anazi Hamoud , Al-Kanaan Adnan , El-Mofty Wael , Bukovac Tomislav 
Published: September 2013

Abstract
Among the various design and operating parameters, efficient acid stimulation in deep carbonate reservoirs depends on the placement technique, injection profile and treatment composition. Unlike acid fracturing, matrix acidizing creates several conductive flow channels with substantially higher conductivity compared to the reservoir rock. These conductive channels transport reservoir fluids from the formation matrix directly into the wellbore overcoming both low permeability and near wellbore damage. The treatment composition, and more importantly, the injection technique to maximize the number and depth of penetration of these conductive channels, are among the most predominant design criteria of successful carbonate matrix acidizing especially in a high-pressure and high temperature environment.
The Permian Khuff carbonate reservoir in the Ghawar structure of Saudi Arabia produces nonassociated gas and condensate. The reservoir is characterized by heterogeneous porosity and permeability distribution extending in both areal and vertical directions with varying in-situ stress contrast along the structure extension. Due to the reservoir complexity, each well requires individual assessment to determine the optimum completion design necessary to achieve efficient matrix or fracture acidizing treatment. Some wells may need simple matrix acid treatment, while other wells may need open hole multistage (OHMS) fracture stimulation. Results demonstrate that OHMS completion was required to successfully stimulate all net pay intervals.
This paper presents an overview of Saudi Aramco’s efforts to evaluate various stimulation methods used in the Khuff reservoir and highlights an optimal carbonate stimulation technique for certain reservoir conditions via the first trial test application of a limited entry OHMS completion for effective stimulation. The technique uses a system that is designed to run as part of the production liner and provides mechanical diversion at specified intervals, thereby allowing multiple matrix acidizing treatments to be effectively placed in the target zones. The technique was applied recently for the first time in Saudi Aramco’s gas program and the details are discussed in this paper.
Design and Evaluation of Hydraulic Fracturing in Tight Gas Reservoirs
Authors: Murtaza Mobeen , Al Naeim Sami , Waleed Asmar 
Published: September 2013

Abstract
As the increasing demand of gas to support the industrial boom grows in the entire world, the unconventional, in particular, extremely tight gas reservoirs are playing significant role. However, the exploitation of these tight resources is still an economical and technical challenge, which can be dealt with the incisive use of current resources. Effective hydraulic fracturing techniques are the only solutions that make the development of these resources economical. This paper is concerned about the method of fracturing treatment design, economical evaluation, candidate selection, and fracture economic optimization. Finally, the detailed financial analysis of fracture job with net production increase is used to select the best stimulation solution for tight gas reservoirs. Moreover, the paper will serve as a good source of information to gain better understanding of hydraulic fracturing design to maximize the economics of tight gas reservoirs.
Mechanical, Rheological and Microstructural Properties of Saudi Type G Cement Slurry with Silica Flour Used in Saudi Oil Field under HTHP Conditions
Authors: Murtaza M. , Rahman M. K. , Al-Majed A. A. , Samad A. 
Published: September 2013

Abstract
With the continued growth of petroleum demand, the oil and gas companies are searching in new or unexplored areas. The search is getting extreme in terms of depth, temperature and pressure. In deeper wells, high temperature and pressure and post cementing operations put extreme stresses on the cement sheath and affect the integrity of the cement. In such conditions, the design of cement slurry is very critical and it must possess properties which ensure the durability and long term integrity of cement sheath.
The purpose of this study is to evaluate the physical properties of Saudi cement class G with silica flour and admixed with different additives such as fluid loss agent, retarder, expanding agent and friction reducing agent under high temperature and pressure conditions. In this paper, we present the results of experimental investigations conducted on class G cement slurry without additives, as a basis, and cement slurry with additives and silica flour. Free water separation, rheological properties, compressive strength, density, scanning electron microscope (SEM), X-Ray diffraction (XRD), porosity and permeability tests were conducted with and without additives at both room and HTHP conditions.
Emerging Technology Transformed the Development of Thin/Tight Layers in a Giant Middle Eastern Field
Authors: AlGhamdi H. M. , ElHayek S. O. , AlHutheli A. H. 
Published: September 2013

Abstract
This paper discusses the successful development of thin/tight layers in a Middle Eastern field with a production history of more than 50 years supported by peripheral water injection. The reservoir is characterized as a carbonate formation and consists of four major layers, namely 1, 2, 3 and 4. Layers-2 and 3 constitute the main reservoir body and are the most prolific layers.
Layer-1, which is the focus of this paper, exposed to production using vertical wells, was not contributing due to its limited thickness and low reservoir quality compared to the other layers.
With the advancement in drilling and geosteering accurate well placement became a reality. Therefore, a multidisciplinary team proposed a pilot well targeting Layer-1 alone to exploit its potential. This pilot was an existing producer in an area where layers-2, 3 and 4 were swept and Layer-1 remaining oil saturation showed the most developed porosity thickness in the field. A geological model was built to evaluate various scenarios to ensure good planning and successful well placement. A proactive geosteering tool was exploited to confront well placement challenges. As a result, the well was drilled with 100% reservoir contact. Post-sidetracking performance was encouraging and opened new opportunities to develop this layer.
This achievement sets the beginning of a new milestone to improve recovery in this field. This paper discusses three major aspects related to this achievement. First, it highlights the pre-assessment of the target location. Also, it discusses the geosteering technology that was utilized to maintain the entire horizontal section across the target layer. Finally, it presents the production performance after the well re-completion.
Advanced Visualization for Reservoir Simulation
Authors: Al-Harbi Badr , Al-Darrab Abdulaziz , Al-Zawawi Ahmed S. , Al-Zamil Khalid 
Published: September 2013

Abstract
This paper provides an overview of an advanced visualization system for visualizing giga-cell simulation models to assist Reservoir Engineers in managing and developing Saudi Arabia’s giant fields. The challenges in the hydrocarbon industry require the use of the latest technology to maximize recovery in a cost-effective manner. Over the last few years, reservoir simulation activities have undergone major transformation toward the use of giga-cell simulation models [1]. This transformation stems from the use of advanced data acquisition solutions and advanced modeling packages to capture and model physically large fields. Fine scale-grid blocks capture detailed description of geologic heterogeneity that is necessary to model the complexity of fluid flow in the subsurface. Giga-cell simulation models are currently generated using Saudi Aramco’s GigaPOWERS parallel reservoir simulator [2]. The size of reservoir simulation models continues to grow to exceed the billion-cell barrier.
The design of a high performance computational platform for simulation of giant reservoir models has been discussed in other literature [3]. In this paper, we focus on the simulation post-processing visualization system developed, which consists of advanced technologies for handling and visualizing massive amounts of data. Implemented techniques include: Remote visualization utilizing graphics processing clusters, parallel data loading, level of detail graphics rendering and hierarchal multi-resolution data structure. In addition, a number of advanced visualization features that have been implemented are highlighted in this paper, such as the ability to display fluid patterns in the field by utilizing streamlines and vector fields, advanced volume visualization techniques based on streamlines and wells filtering to help engineers better understand the fluid flow in subsurface reservoirs. Furthermore, the performance considerations, challenges and impact on reservoir simulation studies are also discussed.
Phase Behavior and Interfacial Tension Properties of an Amphoteric Surfactant for EOR Application
Authors: Fuseni Alhasan , Han Ming , Al-Mobith Adel 
Published: September 2013

Abstract
Amphoteric surfactants are known for their tolerance to salinity and temperature and are considered as likely candidates for enhanced oil recovery (EOR) application in harsh reservoir environments. This study looked into the phase behavior properties of an amphoteric surfactant, OCT-1 and its interfacial lowering capability over weeks. The surfactant concentrations used ranged from 0.05 to 0.5% active and phase behavior studies were conducted with seawater of salinity 57,000 ppm and crude oil at a reservoir temperature 90°C.
Interfacial tension measurements showed that this surfactant is capable of lowering oil-water interfacial tension (IFT) considerably at low surfactant concentrations. Surfactant concentrations of 0.05% and 0.1 % were able to achieve lowest IFTs till a week into the study. Thereafter, only the 0.2 % concentration was able maintain a low IFT till three weeks. A measurement of surfactant concentrations showed that the aqueous phase surfactant concentration stayed much stable for all surfactant concentrations. An examination of photomicrographs revealed that a tiny amount of the oil partitioned into the aqueous phase enhancing the IFT lowering capability of the aqueous phase at these low concentrations.
A Novel and Cost-Effective Clay Control Approach in Water-Sensitive Sandstone Gas Reservoir of Saudi Arabia During Proppant Fracturing Treatment
Authors: Malik Ataur R. , Ghamdi Abdulwahab H. , Senturk Nejla H. , Leal Jairo A. , Atwi Mohammed A. , Soriano Eduardo 
Published: September 2013

Abstract
Clay swelling, dispersion and migration due to water-sensitive clay minerals in the producing formation can substantially reduce rock and retained proppant permeability resulting in reduced well productivity. The effects of water-based fracturing fluids in water-sensitive formations have been extensively investigated which led to development of different types of clay stabilizers based on type of clays, bottomhole temperature, and clay protection time. The use of KCl or NaCl brine up to concentration of 6% is well known clay stabilizing method for swellable and migratory clays during the stimulation treatment.
However, using high salt content brines have some limitations and constrains. The performance of crosslinkers (Borate or Zirconium) and breakers are often affected when using high salt concentration in the base fracturing fluids. The sandstone formations of Saudi Arabia have been reported to be "water-sensitive" and can be easily damaged by fresh water. A novel clay stabilization liquid additive has been successfully introduced as a substitute to inorganic salts in fracturing fluids for sandstone formation in Saudi Arabia. This new permanent clay control additive is cationic polymer with ultra-low molecular weight (PC-4) and compatible with borate and zirconium crosslinkers. It also reduces safety concerns and operational time by eliminating handling and mixing of huge amount of salts on location.
This paper provides details on lab testing, and field implementation of the novel cost effective clay control additive in HTHP sandstone gas well during proppant fracture treatment.
Smart Well Completion Utilization to Optimize Production in MRC Well - A Case Study
Authors: Al-Khalifa Mohammad T. , Mishkhes Abdulrahman T. , Baruah Keshab N. , Al-Otaibi Nashi M. 
Published: September 2013

Abstract
Introducing smart completions was one of the most revolutionary events in the oil industry because it will lead to higher productivity index, longer life, increase in the sweep efficiency, better water management, and it is more cost-effective. Moreover, smart completion gives the company the ability of remote operation and more advances monitoring over the reservoir. Being a leader in the oil industry Saudi Aramco was one of the first companies to implement smart completions in their wells. The inflow control valve (ICV) and permanent downhole monitoring system (PDHMS) in addition to maximum reservoir contact (MRC) are all components of smart completion that are used by Saudi Aramco. Nowadays, smart completion wells are a major contribution in Saudi Aramco fields as they are used to enhance the reservoir sweep.
This paper will show a detailed case study that was done on a smart completion well drilled in a carbonate field. The well is producing from a thin zone and close to the water zone. Smart completion is used to optimize the well production, manage the water production, and prolong the well life. In this case study, multiple single lateral testing was performed on the well over a time interval of 2 years to monitor major changes. The test was made so as to have a better understanding of the water movement and how it can be managed and controlled. The well includes three laterals in addition to the motherbore. The results of those several tests will be shared in this paper, including steps done to maintain the production targets and to decrease water cut along with suggestions that can lead to better results and improve future production optimization tests.
Ensemble Machine Learning: The Latest Development in Computational Intelligence for Petroleum Reservoir Characterization
Authors: Anifowose Fatai A. 
Published: September 2013

Abstract
With the persistent quest for better prediction accuracies of petroleum reservoir properties, research in Computational Intelligence (CI) continues to evolve new techniques to meet this noble objective of petroleum reservoir characterization. In previous presentations, it was established that individual CI techniques are limited in their performance as they have their respective areas of strengths and weaknesses. The concept of Hybrid CI (HCI) was presented to overcome this problem as it utilizes the strengths of two or more techniques to compliment their respective weaknesses. However, the HCI techniques are not able to integrate the various expert opinions on the optimization of CI techniques and those that exist in their respective fields of application. The ensemble learning paradigm is presented here as a possible solution.
The ensemble learning paradigm, also called the committee of learning machines, is the latest development in Computational Intelligence and Machine Learning technologies. It is the method of combining the output of several individual learners with different hypotheses employed to solve the same problem in order to produce an overall best result. The success of this paradigm is based on the belief that the decision of a committee of experts is better than that of a single expert. The ensemble method has been successfully applied in other fields such as bio-informatics, hydrology, time series forecasting, soil science, and control systems. Its benefits have not been well utilized in petroleum engineering.
As a continuation of what has become like a "SPE Computational Intelligence Lecture Series" over the past 2 years, this paper presents an overview of the ensemble learning paradigm, a review of its successful application in other fields, a justification of its necessity in petroleum engineering and a general framework for its successful application in reservoir characterization. This paper will be of benefit to interested persons to explore the exciting world of computational intelligence and for the appreciation of the benefits of the latest development in computational intelligence.
Utility of Urine Eosinophils in the Diagnosis of Acute Interstitial Nephritis
Authors: Muriithi Angela K. , Nasr Samih H. , Leung Nelson 
Published: September 2013

Summary

Background and objectives
Urine eosinophils (UEs) have been shown to correlate with acute interstitial nephritis (AIN) but the four largest series that investigated the test characteristics did not use kidney biopsy as the gold standard.

Design, setting, participants, & measurements
This is a retrospective study of adult patients with biopsy-proven diagnoses and UE tests performed from 1994 to 2011. UEs were tested using Hansel’s stain. Both 1% and 5% UE cutoffs were compared.

Results
This study identified 566 patients with both a UE test and a native kidney biopsy performed within a week of each other. Of these patients, 322 were men and the mean age was 59 years. There were 467 patients with pyuria, defined as at least one white cell per high-power field. There were 91 patients with AIN (80% was drug induced). A variety of kidney diseases had UEs. Using a 1% UE cutoff, the comparison of all patients with AIN to those with all other diagnoses showed 30.8% sensitivity and 68.2% specificity, giving positive and negative likelihood ratios of 0.97 and 1.01, respectively. Given this study’s 16% prevalence of AIN, the positive and negative predictive values were 15.6% and 83.7%, respectively. At the 5% UE cutoff, sensitivity declined, but specificity improved. The presence of pyuria improved the sensitivity somewhat, with a decrease in specificity. UEs were no better at distinguishing AIN from acute tubular necrosis compared with other kidney diseases.

Conclusions
UEs were found in a variety of kidney diseases besides AIN. At the commonly used 1% UE cutoff, the test does not shift pretest probability of AIN in any direction. Even at a 5% cutoff, UEs performed poorly in distinguishing AIN from acute tubular necrosis or other kidney diseases.
Does Reading Case Responses and Using Graphic Organizers Enhance Accounting Students' Case Analyses?
Authors: Phillips Fred , Nagy Alecia 
Published: September 2013

ABSTRACT
This study investigates whether reading case responses and using graphic organizers can assist students in developing case analysis skills, such as identifying supporting arguments and counterarguments in analyses of financial accounting policy choices. The results of an experiment indicate that students who studied an exemplar case response were better able to identify supporting arguments in a subsequent case analysis. In contrast, students who used a graphic organizer to visualize elements of the exemplar case response were better able to identify the absence of counterarguments, which provide support for alternative accounting choices, in a subsequent case analysis. The effects of these pedagogical tools were apparent not only when students evaluated others' case analyses, but also when they generated their own analyses of a subsequent case. These results are significant because they suggest that short (11-minute) instructional interventions can encourage students to adopt two key aspects of critical thinking: identifying and generating relevant arguments and counterarguments.
Data Availability: The data and experimental materials used in this study are available on request from the corresponding author.
Technical Efficiency in the Use of Health Care Resources: A Cross-Country Analysis
Authors: Anton Sorin Gabriel 
Published: September 2013

Abstract
The aim of the paper is to assess the technical efficiency of twenty health systems from Central and Eastern Europe (CEE) and Commonwealth of Independent States (CIS). We used an outputoriented Data Envelopment Analysis (DEA) to measure the technical efficiency of the health systems using the latest data available on infant death and life expectancy as health outcomes. Our results show that technical efficiency varies across these health systems and this translates into potential savings of resources. The average efficiency scores for all heath systems were 0.98 for life expectancy at birth and only 0.821 for infant mortality. More than half of the health systems in the sample were technically inefficient in 2009 for both outputs. We found that 30% of national health systems were technically efficient for both outputs.
Interaction Between Marketing and Informational Technologies in the Insurance Business
Authors: Stofor Ovidiu 
Published: September 2013

Abstract
Business of selling insurance requires great skill especially in this time of difficulty caused by the economic crisis which seems to extend more than anyone had. If by 2008, life insurance offset the gap represented by a long-term savings product to fill in the state pension, after this year, more and more they entered the natural path of protection first. Currently, however, the economic crisis has become an even bigger reason to refuse or postpone the purchase of insurance.