bluuebunny/crossref_metadata_2025 huggingface dataset:
Living With the I-Word: Improvisation and its Alternates
Authors: Labaree Robert
Published: March 2016

The word improvisation is burdened with limitations placed on it by changes occurring in Europe in the 19th century, the period when the model of the hyphenated performer-composer prevailing in Europe up to that point was being split into two specialties. By the 20th century, composition and improvisation had been cast in bronze as mutually defining opposites, the presumed starting point of any approach to how music is made and heard, regardless of historical period or cultural origin. As a way of creating a more critical approach to discourse dependent on the ubiquitous "I-word," this essay seeks to problematize it by focusing on the more general concept of variability itself, or mouvance, as the French literary scholar Paul Zumthor described it in his studies of medieval lyric poetry. More than a century of scholarship on the music of Chopin, the songs of the medieval troubadours, folk music of the British Isles and Balkans, and Turkish classical music—all repertoires which do not rely on the conventions of I-discourse—will provide examples of differing levels of tolerance for performer control of musical events, of different definitions of musicianship, and of different performance poetics. Reflex jazz-related I-genres intentionally play no role in this exercise, forcing us to reflect on I-qualities where we least expect to find them and thus to re-examine our dependence on the I-concept in our thinking about the full spectrum of music-making. None of the I-alternates offered here—musicianship, mouvance, control, variability, or poetics—can be considered competitors for the I-word’s universalizing pretensions, but rather offer insight into what I believe is the I-word’s real content.
“Comprovisation or Imposition?”: An Improvised Composition on a Life of Improvisation
Authors: Stewart Jesse
Published: March 2016

In this essay, originally delivered as the opening keynote address at the 2012 edition of the Guelph Jazz Festival, improvising percussionist and improviser Jesse Stewart reflects on his own experiences as both a student and teacher of improvised music, using those experiences as a way of opening discussion about the ways in which improvisation pedagogy might intersect with the ideas of social justice and social responsibility.
Is Playing in the Pit Really the Pits? Pain, Strength, Music Performance Anxiety, and Workplace Satisfaction in Professional Musicians in Stage, Pit, and Combined Stage/Pit Orchestras
Authors: Kenny Dianna T , Driscoll Tim , Ackermann Bronwen J
Published: March 2016

INTRODUCTION: Typically, Australian orchestral musicians perform on stage, in an orchestra pit, or in a combination of both workplaces. This study explored a range of physical and mental health indicators in musicians who played in these different orchestra types to ascertain whether
orchestra environment was a risk factor affecting musician wellbeing. METHODS: Participants comprised 380 full-time orchestral musicians from the eight major state orchestras in Australia comprised of two dedicated pit orchestras, three stage-only symphonic orchestras, and three mixed stage/pit
orchestras. Participants completed a physical assessment and a range of self-report measures assessing performance-related musculoskeletal disorders (PRMD), physical characteristics including strength and perceived exertion, and psychological health, including music performance anxiety (MPA),
workplace satisfaction, and bullying. RESULTS: Physical characteristics and performance-related musculoskeletal profiles were similar for most factors on the detailed survey completed by orchestra members. The exceptions were that pit musicians demonstrated greater shoulder and elbow strength,
while mixed-workload orchestra musicians had greater flexibility Significantly more exertion was reported by pit musicians when rehearsing and performing. Stage/pit musicians reported less physical exertion when performing in the pit compared with performing on stage. Severity of MPA was significantly
greater in pit musicians than mixed orchestra musicians. Pit musicians also reported more frequent bullying and lower job satisfaction compared with stage musicians. DISCUSSION: There were few differences in the objective physical measures between musicians in the different orchestra types.
However, pit musicians appear more psychologically vulnerable and less satisfied with their work than musicians from the other two orchestra types. The physical and psychological characteristics of musicians who perform in different orchestra types have not been adequately theorized or studied.
We offer some preliminary thoughts that may account for the observed differences.
Occupational Diseases of Professional Orchestra Musicians from Northern Portugal: A Descriptive Study
Authors: Sousa Cláudia M , Machado Jorge P , Greten Henry J , Coimbra Daniela
Published: March 2016

BACKGROUND: Owing to repetitive movements and a very stressful and competitive lifestyle, musicians are a group that may be prone to suffer from occupational diseases. According to the literature, musicians are affected mainly by two types of occupational diseases: music performance
anxiety (MPA) and playing-related musculoskeletal disorders (PRMDs). The aim of this study was to describe the prevalence of the most common complaints affecting musicians in the three professional orchestras from northern Portugal. METHODS: Professional orchestra musicians (n=112) from the
three main professional orchestras from northern Portugal were individually interviewed about their physical and psychological complaints. RESULTS: Results indicated that 94% of musicians interviewed self-reported at least one working-related problem. PRMDs were the most common conditions,
affecting 84.8% of musicians. The most affected areas were the shoulder and the cervical and lumbar regions. MPA was reported by 13.2% of musicians. CONCLUSION: The present work covers about 50% of all Portuguese professional orchestra musicians. It raises awareness of the importance of focusing
on the high prevalence of professional diseases among musicians.
Injuries Among Italian DanceSport Athletes: A Questionnaire Survey
Authors: Pellicciari Leonardo , Piscitelli Daniele , De Vita Marilena , D'Ingianna Lucia , Bacciu Serenella , Perno Giacomo , Lunetta Laura , Rosulescu Eugenia , Cerri Cesare G , Foti Calogero
Published: March 2016

During training and competition, athletic dancers perform complex artistic movements that can lead to stress on the musculoskeletal system, making them subject to high risk of injury. The purpose of this study was to evaluate the prevalence, location, and nature of musculoskeletal injuries
among dancesport athletes and to identify potential risk factors for injury. This cross-sectional study was performed at several national dancesport meetings in Italy. All 168 dancesport athletes who participated at the meetings were invited to complete a questionnaire related to injuries
they may have suffered during the previous year; other information collected included demographic data (age, sex, height, weight), dance participation (discipline, categories), training (training duration, years since starting to dance), and injury (location, etiology). Of the 168 dancers,
153 completed the questionnaire. Of the 102 injuries reported, 73 athletes (47.7%) reported at least 1 injury. The locations of the injuries were the lower limbs (n=75, 73.5%), upper limbs (8, 7.8%), and spine (19, 18.7%). Significant differences were found in the injury location (p<0.01)
as well as the nature of the injury (p<0.01). No significant differences were found between injured and non-injured athletes in demographic data, dance participation, and training variables (p>0.05). The results indicate that about half of the dancers reported at least 1 injury, with
these being located particularly in the lower limbs and predominantly strain and sprain injuries. To reduce the prevalence of injuries, a prevention program may be indicated, with future research needed to identify appropriate strategies to prevent injuries.
Subjective and Objective Analyses of Voice Improvement After Phonosurgery in Professional Voice Users
Authors: Catani Guilherme SA , Hamerschmidt Rogério , Moreira Ana TR , Timi Jorge RR , Wiemes Gislaine RM , Ido Jorge , Macedo Evaldo
Published: March 2016

OBJECTIVES: To evaluate voice improvement after phonosurgery by subjective and objective voice analysis. DESIGN: Prospective observational analytic group study. METHODS: This study was conducted from January 2012 to December 2013. Two hundred forty professional voice users (patients),
classified as Koufman level I or II with benign vocal fold lesions, were divided in two groups. Patients in group 1 had a diagnosis of superficial vocal fold lesions, and patients in group 2 had deep lesions on the vocal folds. All patients completed the Vocal Performance Questionnaire (VPQ)
and underwent acoustic voice tests using the Praat program. Subjective and objective voice analyses were performed before phonosurgery and at 1, 2, and 3 months after phonosurgery. A control group of 100 volunteers was created and underwent the same voice metrics that were applied to the patients.
RESULTS: Jitter, shimmer, harmonic-to-noise ratio, and VPQ scores significantly differentiated patients with vocal fold lesions from individuals in the control group. All of the analyzed parameters improved significantly after phonosurgery. Additionally, patients with superficial vocal fold
lesions achieved normal voice parameters 1 month after surgery, and patients with deep lesions achieved normal voice parameters 3 months after surgery. CONCLUSIONS: Analysis of vocal parameters using the VPQ and acoustic tests revealed voice improvement after phonosurgery for both patient
groups.
Brain Activation During Singing: “Clef de Sol Activation” Is the “Concert” of the Human Brain
Authors: Mavridis Ioannis N , Pyrgelis Efstratios-Stylianos
Published: March 2016

Humans are the most complex singers in nature, and the human voice is thought by many to be the most beautiful musical instrument. Aside from spoken language, singing represents a second mode of acoustic communication in humans. The purpose of this review article is to explore the functional
anatomy of the “singing” brain. Methodologically, the existing literature regarding activation of the human brain during singing was carefully reviewed, with emphasis on the anatomic localization of such activation. Relevant human studies are mainly neuroimaging studies, namely
functional magnetic resonance imaging and positron emission tomography studies. Singing necessitates activation of several cortical, subcortical, cerebellar, and brainstem areas, served and coordinated by multiple neural networks. Functionally vital cortical areas of the frontal, parietal,
and temporal lobes bilaterally participate in the brain’s activation process during singing, confirming the latter’s role in human communication. Perisylvian cortical activity of the right hemisphere seems to be the most crucial component of this activation. This also explains
why aphasic patients due to left hemispheric lesions are able to sing but not speak the same words. The term clef de sol activation is proposed for this crucial perisylvian cortical activation due to the clef de sol shape of the topographical distribution of these cortical areas around the
sylvian fissure. Further research is needed to explore the connectivity and sequence of how the human brain activates to sing.
Abstracts from the Literature, No. 70
Authors: Dawson William J
Published: March 2016

Installment #70.
Cómo tocar sin dolor. By Tomás Martín López
Authors: Rosset-Llobet Jaume
Published: March 2016

Cómo tocar sin dolor: Tu cuerpo tu primer instrument. Ejercicios para la prevención y tratamiento de lesiones en músicos. [How to Play without Pain, in Spanish] By Tomás Martín López. Published by: Piles, Editorial de M.sica SA, March 2015.
ISBN 978-84-15928-59-1.
MPPA Welcomes a New Editor
Authors: Ackermann Bronwen J
Published: March 2016

Welcome to the March 2016 edition of Medical Problems of Performing Artists, and my first editorial as new Editor-in-Chief. It is an honour to be elected to this role. I would like to first and foremost thank my predecessors in this role, Dr. Ralph Manchester and Dr. Alice Brandfonbrener,
for their outstanding contributions as editors, leaving very big shoes to fill.
Risk Factors for Musculoskeletal Disorders in Musicians
Authors: Davies J , Mangion S
Published: March 2016

This letter refers to the systematic review by Sarah Wu addressing occupational risk factors for musculoskeletal (MSK) disorders in musicians, from the June 2007 issue. Our study, “Predictors of pain and other musculoskeletal symptoms among professional instrumental musicians:
elucidating specific effects,” was one of eight papers included in the review, and we are writing to address what we feel were some weaknesses and errors in this review, which may have deterred subsequent researchers in the field from fully examining our paper
Integrated EOR Screening of Major Kuwait Oil Fields Using Qualitative, Quantitative and Risk Screening Criteria
Authors: Al-Mayan Haya , Winkler Mario , Kamal Dawod , AlMahrooqi Sultan , AlMaraghi Eisa
Published: March 2016

A nationwide EOR screening was conducted on major oil fields in Kuwait with the aim to support KOC's long-term production strategy. Taking the many fields, and multitude of reservoirs into account, an efficient screening methodology was applied to high-grade potential EOR targets to focus on the most promising target formations.

This EOR screening methodology is an integrated approach of three steps. The first step applied parametric screening criteria of the various EOR technologies to the target formations of the study. The second step utilized analytical forecast models estimate tertiary recovery factors. The third and final step of this EOR screening methodology focused on generating a technical risk and opportunity profile for each filed, formation and applicable EOR technology.

This EOR screening methodology consisted of three steps. The first step applied parametric screening criteria of the various EOR technologies to the target formations of the study. The EOR processes in this parametric screening exercise included miscible gas EOR (such a CO2 and N2 as an example), chemical EOR technologies as well as thermal recovery technologies. During this first part of the EOR screening, the EOR technology yielding the highest incremental oil recovery in each formation was further studied while using analytical forecast models to link operational recovery drivers, such as throughput volumes and rates, to tertiary recovery factors. The third, and final step of this EOR screening methodology focused on generating a technical risk and opportunity profile for each field and formation under EOR screening while considering aspects such as EOR technology maturity, relative cost comparison and infrastructure constraints, to name a few. Integrating these three screening steps enabled to first, quickly focus on applicable EOR technologies for each target, second quantify a range of tertiary recovery factors and third estimate the risk profile. Combining these three outcomes enable to screen a portfolio of potential EOR opportunities quickly to find the most attractive target for further studies.

The novelty is the integrated EOR screening approach of combining parametric screening, analytical tertiary recovery forecasts and risk profiles to high-grade a portfolio of potential EOR targets for decision making.
Production and Application of Schizophyllan in Microbial Enhanced Heavy Oil Recovery
Authors: Joshi S. J. , Al-Wahaibi Y. M. , Al-Bahry S. , Elshafie A. , Al-Bemani A. S. , Al-Hashmi A. , Samuel P. , Sassi M. , Al-Farsi H. , Al-Mandhari M. S.
Published: March 2016

Generally partially hydrolyzed polyacrylamides (HPAM) are used worldwide for polymer-based oil recovery processes. However there aree some problems associated with HPAM applications such as, treatment of produced water, oil-water separation and toxicity issues associated with degradation products of HPAM. Schizophyllan biopolymer is biodegradable and environmental friendly alternative to chemical polymers used for EOR applications. In present work we studied the schizophyllan production by fungi Schizophyllum commune ATCC38548, its structural characterization and potential applications in Microbial Enhanced Heavy Oil Recovery (MEOR).

Different minimal production media containing carbohydrate based carbon sources were screened for better biopolymer production. During the course of experiments we studied microbial growth profile, biopolymer production, and rheological properties of biopolymer, chemical characterization and application of biopolymer in enhancing heavy oil recovery using Berea sandstone cores.

The biopolymer was produced in significant quantities and increased the viscosity of the production medium after 9 days of incubation. Viscosities were measured using rheometer at different shear rates (0.1-100 s-1) and temperatures, where it was found to be isothermal over a wide range of temperature with strong shear thinning behavior. After 14 days of incubation, the viscosity was 21535 – 43 cP at shear rate from 0.1 – 100 s-1, respectively. Thermogravimetric analysis (TGA) analysis showed that the moisture content in purified biopolymer was 6.3%; it was quite stable till 100-200 °C and melted at temperatures higher than 250 °C. It was characterized as schizophyllan by MALDI-TOF-MS and NMR (1H and proton decoupled 13C NMR) analysis. The repeating tetrasaccharide unit of schizophyllan structure comprised of homoglucan with β-1, 3-linked backbone and single β-1, 6-linked laterally glucose side chains at every third residue. The biopolymer was used for MEOR experiments at 45 °C, using Berea sandstone core plugs. The biopolymer injection resulted in 28% additional heavy oil recovery over residual oil saturation (Sor).
Management of Viscosity of the Back Produced Viscosified Water
Authors: Rambeau Odile , Alves Marie-Hélène , Andreu Nathalie , Loriau Matthieu , Passade-Boupat Nicolas
Published: March 2016

A side effect of EOR polymer flooding on topsides process chain is the generation of stable thin emulsion in viscous water phase. Both viscosity and severe emulsion impede the efficiency of water treatment technologies. The viscosity of the back produced polymer increases the time of clarification of oily water phase. The target of the water treatment specialist would be to collapse the viscosity of the produced water.

The main concern is to decrease the viscosity of the produced water containing polymer back produced, acting on the degradation of the polymer without generating more severe oily emulsion. Shearing, a well known mode of degradation has been compared to other techniques such as chemical oxidation (bleach) and sonication. All the tests were performed with a high molecular weight polyacrylamide commonly used in EOR; at bench lab scale on synthetic viscosified produced water and on back produced water from field with cEOR flooding. Degradation efficiency was evaluated through viscosity measurements and polymer molecular weight analyses.

This paper presents the results of the different investigations carried out to drop the viscosity of the produced water to an acceptable value for water treatment. Chemical oxidation using bleach has proved its efficiency on synthetic produced water. Different shearing conditions and different powers of sonication have also highlighted actions on the polymer and on the viscosity of the water phase.

Even if all the tested degradations lead to a significant viscosity drop of the synthetic viscosified water, the improvements on water treatment were not equivalent. Analytical measurements of the molecular weight of the degraded polymer allowed initiating a scale of degradation efficiency.

The efficiency, feasibility, difficulty, beneficial impact on water treatment and level of readiness of the technology have been estimated. An assessment of the different techniques for the polymer degradation in water treatment is presented at the end of this paper.

The feasibility to decrease the viscosity of the back produced water would allow to simplify the water treatment process chain dedicated to polymer flooding case. Works continues on integrated water treatment process, including pre-degradation of the polymer back produced.
Modeling of CO2 EOR Process Combined with Intermediate Hydrocarbon Solvents for Higher Recovery Efficiency
Authors: Cho Jinhyung , Kim Tae Hong , Lee Kun Sang
Published: March 2016

The addition of intermediate hydrocarbon solvents such as liquefied petroleum gas (LPG) to the CO2 stream leads to miscible conditions in reservoirs at lower pressures by reducing the minimum miscibility pressure (MMP). Under miscible conditions, higher recovery is obtained by simultaneous improvement in displacement and vertical sweepout. A compositional model for CO2-LPG-enhanced oil recovery (EOR) was applied to investigate the complicated phenomenon more accurately. The influences of LPG concentration and composition on the displacement and sweep efficiencies during CO2-LPG EOR were examined. Enhanced displacement efficiency was assessed through oil density, viscosity, and the interfacial tension (IFT) between oil and gas. Moreover, the miscible flooding induced by LPG addition resulted in increased solvent viscosity and a lower density difference between the injected fluid and reservoir oil. It also provided a smaller viscous gravity number and improved the sweep efficiency, alleviating the impact of solvent gravity override. As the mole fraction of the total injected LPG and the LPG butane contents increased, significant increments in oil recovery were obtained from the reduction of MMP, oil viscosity, and IFT. The oil viscosity was reduced to 0.65 cp by CO2 and 0.26 cp with the addition of 25% LPG leading to miscible condition. In CO2-swept regions, the IFT became non-zero due to the immiscible conditions. The addition of 25% LPG into the CO2 stream resulted in negligible IFT in the swept area, indicating miscible conditions. For CO2 flooding, 11.9% of the total reservoir area remained in unswept and immiscible conditions despite the long production time. In contrast, the unswept area was reduced to only 2.4% of the total area when 25% LPG was injected into the CO2 stream under miscible conditions, and the viscous gravity number decreased to 0.9 from 3.8 in the CO2 flooding case. For CO2-LPG EOR, oil recovery increased up to 52% as compared with that for CO2 flooding. The amount of incremental oil recovery with 100% butane in the LPG was 16%, as compared with the 100% propane case. Mitigated gravity override enabled CO2-LPG EOR to enhance sweep efficiency. Results indicated that the efficiency of the EOR process with the addition of LPG as evaluated in the compositional model provided more accurate prediction on the performance of CO2-LPG EOR.
Long-term Utilization of Early Depletion Facilities (EDF) as a First Phase of MGI-EOR Development for Sour Fields in South Oman
Authors: Al-Hadhrami Abdullah , Schulz Ralf , Barwani Shihab , D'Amours Kevin
Published: March 2016

Since the mid 1990's a number of sour, carbonate oil fields have been discovered in the South of Oman. During this time it became apparent that due to the high initial pressures and the high H2S (up to 10 mol%) and CO2 content (up to 25 mol%) of the light crude, the full field development of these carbonate stringers by a miscible gas injection method would be very capital intensive.

Because of the risk on capital and the related subsurface uncertainties, it was decided in the early 2000's to take a phased approach to the development of these fields. This was excuted via the installation of Early Depletion Facilities (EDF) and of a connection to an existing production station 40 km away, capital expenditure was limited and thus the risk of the development minimised. The EDF comprised of 4 manifolds, a remote gathering station, a 69km trunkline and installation of a new separation train and gas injector compressor at the existing station. These facilities were brought on stream in 2004. At that time the end of the EDF production phase was predicted to be 2013, however with the continuous discovery of further fields and delay of the full field development by a new production station, the EDF system has still been in full utilization until present day.

Thus, the EDF will be operational for almost 2 decades. During this time very significant oil revenue income has been generated, while key subsurface data for understanding the connectivity and the behaviour of the fields has been accomplished.

In this paper, the EDF system and the challenges in installation and operation will be discussed. The related information obtained regarding the depletion behaviour of the fields will be shown in some field examples. Field S showed a much higher depletion than anticipated, which resulted in STOIIP reduction and subsequent well location optimisation had to be carried out; field D production behaviour has been much better than expected, however connectivity was found to be an issue; field G alternatively, showed mixed reservoir performance.
Development and Evaluation of Gel-based Conformance Control for a High Salinity and High Temperature Carbonate
Authors: Wang J. , AlSofi A. M. , AlBoqmi A. M.
Published: March 2016

The extreme heterogeneity of carbonate in the form of fracture corridors and super-permeability thief zones challenges the efficient sweep of oil in both secondary and tertiary recovery operations. In such reservoirs, conformance control is crucial to ensure injected water and any enhanced oil recovery (EOR) chemicals optimally contact the remaining oil with minimal throughput. Gel-based conformance control has been successfully applied on both sandstone and carbonate reservoirs. In-depth conformance control in high temperature reservoirs is still a challenge, due to severe gel syneresis and the associated significant reduction in gelation time.

In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for application in a high salinity and high temperature carbonate reservoir. Gel formulation was evaluated using different lab experiments including gelation time, gel strength, and long-term stability. Gelation time was determined by bottle tests and viscosity measurements. Long-term stability was evaluated both in bulk and in a core sample. For long-term gel stability in cores, a single-phase displacement experiment was performed to evaluate the ability of the selected gel system to effectively block high permeability zones. Multiphase displacement experiments were then conducted to evaluate the effectiveness of the gel treatment in oil recovery improvement. In these tests, the gel solution was injected into specially prepared heterogeneous carbonate core samples, in which high permeability channels were created by drilling centrally and mid-way through two core plugs that were brought together to constitute each composite core system.

Single-phase displacement experiments showed significant reduction in brine permeability after gel treatment. Even when the bulk gel volume was reduced by 50%, the original brine permeability is lowered by more than 80%. Multiphase displacement experiments demonstrated significant incremental recoveries post gel treatment. For example, a surfactant-polymer (SP) flood conducted after gel treatment resulted in an ultimate oil recovery of 83% original oil in core (OOIC), while without any gel treatment the SP flood attained an ultimate oil recovery of 67% OOIC. Results in this study demonstrate the potential of the studied gel system and its favorable impact on sweep efficiency for both water and chemical flooding applications in high temperature and high salinity carbonates.
Laboratory Investigation of Polymeric Surfactants for EOR in High Salinity and High Temperature Reservoir
Authors: Guo Lijuan , Han Ming , Fuseni Alhasan , AlSofi Abdulkareem
Published: March 2016

Great attention has been paid recently to polymeric surfactants due to their structure. The incorporation of polymer and surfactant properties in one macromolecule offers significant advantages for chemical flooding. Aiming at high salinity and high temperature reservoirs, several polymeric surfactants were investigated for their potential in improving oil recovery. Experimental results demonstrated polymeric surfactants' good compatibility with field brines (both injection and produced brines). The interfacial tension (IFT) can be reduced by one order of magnitude compared to regular polymer solutions that have no surface activity. The emulsification can be significantly increased, too. The viscosity of the polymeric surfactants is much higher than regular surfactant solutions. With these unique properties, polymeric surfactants are considered a potential alternative to traditional surfactant-polymer formulations for chemical flooding in high salinity and high temperature reservoirs.
A New Approach to Obtain Producer FBHP and FBHT from SCADA Data in the Schoonebeek Steamflood
Authors: Zakharov Alexander
Published: March 2016

Two novel methods are presented, that allow estimating downhole P&T conditions by using wellhead measurements in the Schoonebeek steamflood development: one method allows determining flowing bottomhole pressure (fBHP) and the other bottomhole temperature (fBHT). The resultant estimates are confirmed by fluid level measurements and observation well pressure data.

The fBHP calculation is based on the fact that rod loads are dependent on fluid level. A simple but robust model is presented, which accounts for impact of other parameters (pump speed, watercut, etc.) and allows fine-tuning to match available downhole measurements. The fBHT is estimated by using a simplified analytical wellbore heat loss model that is history matched to wellhead temperatures (WHT) at different well rates.

Both models are applied in the Schoonebeek field steam flood development. Their creation was necessary because operational constraints severely restricted usage of standard surveillance techniques like fluid level measurement and use of downhole gauges on hot producers.

The presented methods allow acquiring robust estimates of downhole P&T regime for flowing producers by using easily accessible SCADA data that is continuously collected at the wellhead. These data are normally used to optimize the rod pump operation and have been recorded since the start of the steamflood (2011–2015); hence, by using simplified rod load models and some statistical analysis it was possible to recover and validate the full fBHP/fBHT history for the hot wells – even for the periods when the fluid level measurements were unavailable or inconsistent.

The models were tested and matched against historical field measurements (fluid level measurements and data from observation wells) and were found to provide sufficient accuracy for use in normal operations (P&T within a few bars / 10 degrees C).

The novelty of the methods is in the ability to use existing wellhead data to come up with robust estimates for downhole P&T conditions on flowing wells. Nowadays continuous SCADA are industry standard; thus, near-continuous fBHP and fBHT monitoring can be achieved without using any additional equipment.

Clear benefits are surveillance cost reduction together with improved well/reservoir management; also, extra data helps improving reservoir model history match quality and forecast accuracy.
Impact of Oil on Steam Foam Formulations at 250°C
Authors: Cuenca Amandine , Lacombe Emie , Chabert Max , Morvan Mikel , Delamaide Eric
Published: March 2016

The most widespread thermal EOR method relies on steam injection. Steam is employed to warm up the reservoir, increase oil mobility and in turn enhance heavy oil recovery. In steam injection processes, recovery of oil is limited by steam channeling due to reservoir heterogeneities. Early breakthrough implies large consumption of steam and incomplete reservoir drainage. A low cost viable option to minimize heat loss consists in generating steam foam in situ. Foam will reduce steam mobility, increase its apparent viscosity and reduce steam channeling. Foam should form and flow in reservoir swept regions containing residual oil saturation. For a field application, where the residual oil saturation may vary from 0 to 30% depending on the recovery method applied, any effect of the oil on foam stability becomes a crucial matter. The scope of this work is to design an appropriate foaming surfactant solution in reservoir representative conditions of 250°C. We study the impact of crude oil on its foaming properties.

Previous publications demonstrate that formulation viscosity as well as foamability and foam stability are key parameters to optimize steam mobility reduction in model porous media. It is also well known that measuring foam properties at 200°C in presence of heavy crude oil is an experimental challenge. Injecting heavy oil in common equipment is often problematic, due to its high viscosity and low flowability. Our methodology is based on the use of high pressure/high temperature set-ups, such as sapphire view cell to measure foam stability, capillary rheometer to measure formulation viscosity and high temperature sandpack experiments to measure gas mobility reduction in model porous media. We also present a new high pressure/high temperature screening tool based on disposable containers to evaluate foaming properties in presence of heavy crude oil.

We have shown in previous work that long chain surfactants present high foam forming ability at 200°C. We build on our knowledge to demonstrate foam existence at 250°C. This study highlights the performance of new foaming formulations at this temperature. Our development effort has been concentrated on building a novel experimental setup and also providing data to evaluate the impact of heavy crude oil on foaming performances. Based on our experimental results, we demonstrate that foam stability in presence of crude oil can be improved by surfactant synergetic associations.

Overall, this work offers new insights to design efficient steam foaming formulations up to 250°C, in particular in presence of heavy crude oil. This novel approach helps in developing more efficient steam foam EOR solutions and in optimizing steam injection processes.
Challenges in Full Field Polymer Injection Mangala in Field
Authors: Mehta Nirav , Kapadia Gautam , Panneer Selvam V
Published: March 2016

Polymer flood process has the potential to significantly improve sweep efficiency in the fields with viscous oil, due to unfavorable water-flood oil-water mobility ratio resulting in a relatively inefficient water-flood. A successful field implementation would lead to extended production plateau and increased ultimate recovery (EUR). Cairn India Ltd is engaged in Oil and Gas exploration and production in RJ-ON onshore block in India. Mangala oil field is the largest discovered field with significant oil production potential (Total estimated water flood recovery of around 37 %). The field which contains moderately viscous but waxy oil with high pour point is currently under hot water flood to provide pressure support, sweep and prevent any in-situ wax drop-out. Post success of a polymer pilot trial, the full field polymer flood project is being implemented in the field with the concept of a Central polymer preparation plant distributing the concentrated polymer mother solution to the injection wells which are scattered across the field. The mother solution is diluted with the injection water to required polymer concentration before final injection into the well. Full field Polymer Injection it is expected to yield additional recovery of 5–7% of the STOIIP over base water flood.

This paper discusses the challenges faced during the execution of the polymer injection in the full scale with respect to, Supply chain management of polymer w.r.t framing the polymer supply contracts, screening of multiple vendors in different geographical location and the logistics management of large volumes of polymer,Laboratory techniques in screening the polymer, challenges faced in laboratory measurements including viscosity measurement in aerobic/anaerobic conditions, low shear high pressure sampling, and compatibility of oil field chemical additives with Polymer,Operational challenges including viscosity with available water quality & higher oil in water, TSS, Fe content and impact of temperature variation on viscosity of mother solution and diluted polymer solution,Produced fluid handling challenges with Polymer breakthrough with respect to adequacy of oil-water-gas treatment facility to handle emulsion, scaling/gelling issues in heat exchangers and the capacity limitations caused by viscosity and hydraulics.

To summarize, for the full field polymer injection, the challenges discussed with respect to unwieldy logistics of polymer procurement, mother and dilute polymer solution preparation at low shear and high pressure environment followed by polymer breakthrough resulting in tighter emulsion, etc need to be addressed proactively in order to achieve the targeted recovery from the Project. The focused efforts on these areas of concern are the drives for the success of all the stakeholders.
Comparison of Implicit-Texture and Population-Balance Foam Models
Authors: Lotfollahi Mohammad , Farajzadeh Rouhi , Delshad Mojdeh , Varavei Abdoljalil , Rossen William R.
Published: March 2016

Simulation models for foam enhanced oil recovery are of two types: those that treat foam texture or bubble size explicitly (population-balance models) and those that treat the effects of foam texture implicitly through a gas mobility-reduction factor. The implicit-texture models all implicitly assume local equilibrium (LE) between the processes of foam creation and destruction. In published studies most population-balance models predict rapid attainment of local-equilibrium as well, and some have been recast in LE versions.

In this paper we compare population-balance and implicit-texture (IT) models in two ways. First, we show the equivalence of the two approaches by deriving explicitly the foam texture and foam-coalescence-rate function implicit in the IT models, and then show its similarity to that in population-balance models. Second, we compare the models based on their ability to represent a set of N2 and CO2 steady-state foam experiments and discuss the corresponding parameters of the different methods.

Each of the IT models examined was equivalent to the LE formulation of a population-balance model with a lamella-destruction function that increases abruptly in the vicinity of the limiting capillary pressure Pc*, as in current population-balance models. The relation between steady-state foam texture and water saturation or capillary pressure implicit in the IT models is essentially the same as that in the population-balance models. The IT and population-balance models match the experimental data presented equally well. The IT models examined allow for flexibility in making the abruptness of the coalescence rate near Pc* an adjustable parameter. Some allow for coarse foam to survive at high capillary pressure, and allow for a range of power-law non-Newtonian behavior in the low-quality regime.

Thus the IT models that incorporate an abrupt change in foam properties near a given water saturation can be recast as LE versions of corresponding population-balance models with a lamella-destruction function similar to those in current PB models. The trends in dimensionless foam texture implicit in the IT models is similar to that in the PB models. In other words, both types of model, at least in the LE approximation, equally honor the physics of foam behavior in porous media.
Polymer Injectivity Test in Bhagyam Field: Planning, Execution and Data Analysis
Authors: Sharma K Kaladhar , Mishra Sudhakar , Kumar Pankaj , Pandey Amitabh , Jain Shakti , Ghosh Priyam , Mishra Lokranjan , Koduru Nitish , Agrawal Nitesh , Kushwaha Malay Kumar
Published: March 2016

The Bhagyam Field development is part of the Mangala- Bhagyam -Aishwariya (MBA) development in the Barmer Basin, Rajasthan, India. The Bhagyam field is a shallow field with ~12B dip, containing good quality fluvial sand(s), medium gravity crude with a viscosity gradient (vertically) in the oil column and low water salinity (~5000 ppm). The field is currently being developed using down-dip water injection. The effectiveness of the waterflood will be limited by the adverse mobility ratio and reservoir heterogeneities. A polymer injectivity test was conducted in two wells with two main objectives: (1) to establish injectivity within the designed surface pressure, and (2) establish the ability to prepare polymer solutions of the desired viscosity using produced water for re-injection (PWRI).

Operationally, the test was conducted using a skid mounted unit with regular monitoring facilities in place. Surveillance activities included frequent spinner surveys, bottom-hole pressure measurements, fall-off tests and offset production well tests. Rigorous monitoring of injection water quality, polymer solution quality was carried out. An inline viscometer was used for continuous polymer viscosity monitoring. This was supplemented by periodic sample viscosity measurements using special samplers with chemical stabilizers. The test was conducted in two wells and important lessons have been learnt which would be incorporated during full-field implementation of a polymer flood in Bhagyam.

The injectivity test establishes that polymer injection is viable in Bhagyam Fatehgarh reservoirs. A history matching exercise was carried out using a sector model extracted from our full-field simulation model. The effect of production and injection in offset wells was captured in the sector model. Local grid refinement enabled us to adequately capture polymer rheology. The modelled rheology was found to be in close agreement with laboratory data. The production history of the wells in the sector and vertical injection profile of the injector well was incorporated. We obtained a good history match of the injection bottom-hole pressures.

This paper presents details of the polymer injectivity tests including bottom-hole pressure measurements, fall-off tests and production logging which were conducted during the tests. As PWRI was utilized for preparing polymer solution, the effect of additives to the polymer solution viscosity was also analyzed. The test included use of not so commonly used equipment like inline viscometer, special samplers with chemical stabilizers, preparation of high concentration mother solution and injection of heated polymer solution.
Use of Solvents With Steam - State-of-the-Art and Limitations
Authors: Bayestehparvin Bita , Ali S. M. , Abedi Jalal
Published: March 2016

Steam injection is a widely used oil recovery method that has been commercially successful in many types of heavy oil reservoirs, including oil sands of Alberta. Steam is very effective in delivering heat that is the key to heavy oil mobilization. In the distant past, and also recently, solvents are being used as additives to steam for additional viscosity reduction. This was done previously in California heavy oil reservoirs also. The current applications are in SAGD (Steam-Assisted Gravity Drainage) and CSS (Cyclic Steam Stimulation) field projects.

The past and present projects using solvents are reviewed, and evaluated viz ES-SAGD (Enhanced solvent SAGD) and LASER (Liquid Addition to Steam for Enhancing Recovery). The theories behind the use of solvents with steam are outlined. These postulate (1) additional heavy oil mobilization; (2) oil mobilization ahead of the steam front, and (3) oil mobilization by solvent dispersion due to frontal instability. The plausibility of the different approaches is discussed.

Recent theoretical work is described that compares thermal and solvent diffusion, showing that the time scales of the two processes are quite different casting doubt on the effectiveness of the use of solvents with steam. The numerical and analytical solutions have been compared for effect of cold solvent, hot solvent, steam only, and co-injection of solvent and steam on bitumen mobilization.

The outcome of this study can be used for better understanding of mechanisms and theories behind co-injection of solvent with steam.
Case Study in Middle East, Improve Heavy Oil Production and Recovery by Reservoir Modification as Alternative Technology to Steam and Miscible Gas Injection
Authors: Al Saadi Hassan , Mirza Mirza , Al Amri Bader , Mucharam Leksono , Nugroho Wisnu , Al-Hinai Khaldoon
Published: March 2016

Increasing oil production and recovery for Heavy Oil can be achieved by reducing oil viscosity. With reference to Darcy law, reducing the oil viscosity results in an increase in oil productivity. The current technologies for reducing viscosity are Steam injection and Miscible Gas (hydrocarbon or carbon dioxide) injection. However both steam and miscible gas has technical and economic limitations, and an alternative technology is required to extend beyond the limitations in both steam and miscible gas injection.

The technology described herein is based on reservoir fluid and rock modification by chemical technology approach. Reservoir modifications are made by ability to mix between oil and water, and the mixed viscosity is designed to be reduced to close to, but higher than, water viscosity. Because the viscosity is still higher than water viscosity, the fluid flow becomes slower and will have enough time to react with oil and divert to the oil bank. When the modified chemical is diverted to the oil bank, then wettability alteration acts to peel out oil from the rock surface and has ability to pass through pore throatand hence flow to producing oil well.

The research programewasconducted by mimicking reservoir behaviorby implementing mixture viscosity sensitivity performance test, imbibition tube test and coreflood test. The tests are implemented usingactual reservoir oil, water and rock. The result of viscosity reduction is able to reduce oil viscosity from more than 376 cp at reservoir temperature to less than 10 cp mixture viscosity at temperature between 60 and 90° C. For comparison, steam injection is able to reduce viscosity of heavy oil to become less than 10 cp, but requires a temperature of 350° C instead of 60 to 90° C. The imbibition test has shown incremental oil recovery at 14.7 psi (atm pressure) of two times that of reservoir water only, while the laboratory result with coreflood shows additional recovery after chemical injection of 30% to 50% beyond primary and water injection stage.

The implementation is technically simple and it is able to be conducted at relatively low cost. The result from implementation by well basis injection yielded a significant increase in oil production. By sharing this road map experience from laboratory result to field implementation of the new method of chemicalstimulation forheavyoil production, it provides an alternative to improve production and recovery of heavyoil, especially in the Middle East.