bluuebunny/crossref_metadata_2025 huggingface dataset:
Dig It: Looking for Fame in All the Wrong Places
Authors: Garber Marjorie
Published: October 2011

The national book award for nonfiction was given in 2010 to Patti Smith for her book just kids. Since Patti Smith is a rock star as well as a poet and “punk icon,” her heartfelt remarks at the awards ceremony did more for the book business than any other tribute could have done. Smith told the assembled guests that as a young woman working at the Scribner Book Store, shelving books emblazoned with the National Book Award logo, she had dreamed of writing such a book herself. She concluded her acceptance speech with an impassioned defense of the printed book: “Please, no matter how we advance technologically, please never abandon the book. There is nothing in our material world more beautiful than the book” (“National Book Awards—2010”).
The Thinking Voice: When Listening Trumps Celebrity
Authors: Fiol-Matta Licia
Published: October 2011

In the brief span of 1952–68, Puerto Rico sped through its industrialization process. Middle-class residential construction dotted the city of San Juan. Hotels replaced the mansions along its Condado waterfront. The spanking new Medical Center promised health for the sickly, undernourished population, a health that the developmentalist program of the Commonwealth of Puerto Rico—Operation Bootstrap—desperately needed, as it endeavored to offer a cheap, obedient, and presumably bilingual labor force to American capital. The “Golden Mile,” the financial district established in the area of the sometime royal hacienda, Hato Rey, emerged as the centerpiece of a new downtown. The mythic mall of Plaza Las Américas (formerly a cattle ranch that bred cows for the milk industry) became the social hub of a polis that increasingly turned to consumerism for its exercise of citizenship. Newspapers and magazines were filled with consumer fantasies of every variety. Along with everything else that was dazzling and new, Puerto Rico consumed a new object for sale, the celebrity pop star.
Dante and the Laws of Infamy
Authors: Steinberg Justin
Published: October 2011

Dante refers persistently in his writing to the great injustice of his exile. Up until his last years, he continues to lament his inability to return home. Originally banished for two years after being indicted by his political enemies for corruption and graft in 1302, he was subsequently sentenced, along with his sons, to death by fire if he ever dared to reenter Florence. The animosity toward his fellow citizens he expresses in his writing, alongside his frustrated sense of betrayal, is thus easy to understand. In works such as De vulgari eloquentia and the Convivio, he bitterly evokes the conditions of his banishment, while in the Latin epistles he succinctly and tellingly identifies himself as an exul immeritus (“undeserving exile”).
Guest Column—Epilogue: Celebrity's Face Book
Authors: Wicke Jennifer
Published: October 2011

Celebrity relies on a gaze, a collective or public regard that, in gazing, confers value. Celebrity also demands a face to celebrate—faciality is a sine qua non of “celebrification.” The historian Peter Brown demonstrates inThe Cult of the Saintsthat late antiquity introduced the overriding importance of saints' images, bodies, relics, or tomb sites in a Christian worship that emphasized the mediation of saints between heaven and earth and in place of angels; celebrity had its origins in the woodcut portraits and wayside shrines that proliferated as well as in the professionally wrought iconic images of the saints. Against David Hume's judgment of this phenomenon as “vulgar” and a remnant of pagan folk religion, he argues that the rise of the cult of the saints was as influenced by elites, including Augustine, as by supposedly lesser folk, and that the latter, especially women and the poor, were thus able to participate in a democratizing of culture profoundly indebted to graveside practices that promoted personal relationships, even friendships, with the dead saints and the circulation of their faces in imagery and their body parts as relics (17). Moreover, far from introducing vulgarity into Christian rituals, Brown shows how the cult was imbued with the culture of classical antiquity and with values associated with Athenian democracy and the philosophy of nous, a non-rational intelligence linking us to the divine (48). That we deploy the termcelebrity iconfor such figures as Oprah or Angelina Jolie only underscores the vestiges of public religious ritual that remain embedded in celebrity practices and the nimbus of the sacred that haloes even seemingly debased celebrity discourses.
Celebrity Shylock
Authors: Anderson Emily Hodgson
Published: October 2011

This essay proposes the celebrity of fictive bodies and seeks to understand how, and how far, certain fictional characters can stimulate an audience response analogous to that elicited by the flesh and blood. One of many “celebrity characters,” Shylock is useful to this discussion in regard to the historical development of his fame: Shylock on the eighteenth-century stage begins a new kind of fascination with this character. Seeking to explain that fact, the essay outlines aspects of eighteenth-century theatrical practice that enabled audiences to consider character apart from actor and then, to showcase this shift, develops two valences of the eighteenth-century response to Shylock—the tendencies toward judgment and conversion. Both responses demonstrate how a dramatic character invokes (and complicates) the tensions between public and private life that theorists have used to define celebrity appeal.
The Personal Public Sphere of Whitman's 1840s Journalism
Authors: O'Neill Bonnie Carr
Published: October 2011

Before Walt Whitman became the self-celebrating poet ofLeaves of Grass, he was a professional journalist. This paper examines the journalism Whitman produced from 1840 to 1842 in the context of an emerging celebrity culture, and it considers celebrity's effects on the public sphere. It traces the penny press's personal style of journalism to both its artisan-republican politics and the formation of celebrity culture, in which celebrities assume status parallel to that of traditional representatives of authority. As editor of theAurora, Whitman adopts the first-person, polemical style of the penny press and singles out prominent people for criticism. In other pieces, he presents himself as the ever-observant flâneur. As editor and as flâneur, he is a participant in and observer of the life of his community, and he assumes unassailable interpretive power. But he also regards his readers as fellow participants-observers who make judgments about the public figures he reports on. The tension between these positions is never resolved: Whitman's dialogic addresses to readers aim to extend the public sphere of critical debate even as Whitman holds steadfastly to his own social and political authority. Encouraging and modeling readers' negotiations over the meaning of public figures, he extends the features of celebrity culture to the public at large. His early journalism shows how and why it is so difficult to reconcile political and social community in the era of mass culture, and it highlights the complexities of the coexistence of celebrity and critical discourse in the personal public sphere.
Evaluating the impacts of multiple generalist fungal pathogens on temperate tree seedling survival
Authors: Hersh Michelle H. , Vilgalys Rytas , Clark James S.
Published: October 2011

Host‐specific mortality driven by natural enemies is a widely discussed mechanism for explaining plant diversity. In principle, populations of plant species can be regulated by distinct host‐specific natural enemies that have weak or nonexistent effects on heterospecific competitors, preventing any single species from becoming dominant and thus promoting diversity. Two of the first steps in exploring the role of natural enemies in diversity regulation are to (1) identify potential enemies and (2) evaluate their levels of host specificity by determining if interactions between any one host and its enemy have equivalent survival impacts on co‐occurring host species. We developed a bioinformatics framework to evaluate impacts of potential pathogens on seedling survival, for both single and multiple infections. Importantly, we consider scenarios not only if there are specialist pathogens for each plant, but also when generalist pathogens have differential effects on multiple host species, and when co‐infection has species‐specific effects. We then applied this analytical framework to a field experiment using molecular techniques to detect potential fungal pathogens on co‐occurring tree seedling hosts. Combinatorial complexity created by 160 plant–fungus interactions was reduced to eight combinations that affect seedling survival. Potential fungal pathogens had broad host ranges, but seedling species were each regulated by different combinations of fungi or by generalist fungi that had differential effects on multiple plant species. Soil moisture can have the potential to shift the nature of the interactions in some plant–fungal combinations from neutral to detrimental. Reassessing the assumption of single‐enemy–single‐host interactions broadens the mechanisms through which natural enemies can influence plant diversity.
Trait similarity patterns within grass and grasshopper communities: multitrophic community assembly at work
Authors: Van der Plas F , Anderson T. M. , Olff H
Published: October 2011

Trait‐based community assembly theory suggests that trait variation among co‐occurring species is shaped by two main processes: abiotic filtering, important in stressful environments and promoting similarity, and competition, more important in productive environments and promoting dissimilarity. Previous studies have indeed found trait similarity to decline along productivity gradients. However, these studies have always been done on single trophic levels. Here, we investigated how interactions between trophic levels affect trait similarity patterns along environmental gradients. We propose three hypotheses for the main drivers of trait similarity patterns of plants and herbivores along environmental gradients: (1) environmental control of both, (2) bottom‐up control of herbivore trait variation, and (3) top‐down control of grass trait variation.

To test this, we collected data on the community composition and trait variation of grasses (41 species) and grasshoppers (53 species) in 50 plots in a South African savanna. Structural equation models were used to investigate how the range and spacing of within‐community functional trait values of both grasses and their insect herbivores (grasshoppers; Acrididae) respond to (1) rainfall and fire frequency gradients and (2) the trait similarity patterns of the other trophic level.

The analyses revealed that traits of co‐occurring grasses became more similar toward lower rainfall and higher fire frequency (environmental control), while showing little evidence for top‐down control. Grasshopper trait range patterns, on the other hand, were mostly directly driven by vegetation structure and grass trait range patterns (bottom‐up control), while environmental factors had mostly indirect effects via plant traits. Our study shows the potential to expand trait‐based community assembly theory to include trophic interactions.
Vulnerability of the northern Mongolian steppe to climate change: insights from flower production and phenology
Authors: Liancourt Pierre , Spence Laura A. , Boldgiv Bazartseren , Lkhagva Ariuntsetseg , Helliker Brent R. , Casper Brenda B. , Petraitis Peter S.
Published: October 2011

The semiarid, northern Mongolian steppe, which still supports pastoral nomads who have used the steppe for millennia, has experienced an average 1.7°C temperature rise over the past 40 years. Continuing climate change is likely to affect flowering phenology and flower numbers with potentially important consequences for plant community composition, ecosystem services, and herder livelihoods. Over the growing seasons of 2009 and 2010, we examined flowering responses to climate manipulation using open‐top passive warming chambers (OTCs) at two locations on a south‐facing slope: one on the moister, cooler lower slope and the other on the drier, warmer upper slope, where a watering treatment was added in a factorial design with warming. Canonical analysis of principal coordinates (CAP) revealed that OTCs reduced flower production and delayed peak flowering in graminoids as a whole but only affected forbs on the upper slope, where peak flowering was also delayed. OTCs affected flowering phenology in seven of eight species, which were examined individually, either by altering the time of peak flowering and/or the onset and/or cessation of flowering, as revealed by survival analysis. In 2010, which was the drier year, OTCs reduced flower production in two grasses but increased production in an annual forb found only on the upper slope. The particular effects of OTCs on phenology, and whether they caused an extension or contraction of the flowering season, differed among species, and often depended on year, or slope, or watering treatment; however, a relatively strong pattern emerged for 2010 when four species showed a contraction of the flowering season in OTCs. Watering increased flower production in two species in 2010, but slope location more often affected flowering phenology than did watering. Our results show the importance of taking landscape‐scale variation into account in climate change studies and also contrasted with those of several studies set in cold, but wetter systems, where warming often causes greater or accelerated flower production. In cold, water‐limited systems like the Mongolian steppe, warming may reduce flower numbers or the length of the flowering season by adding to water stress more than it relieves cold stress.
Well Test Analysis of Multiple Hydraulically Fractured Horizontal Wells MHFHW in Gas Condensate Reservoirs
Authors: Mavaddat M. , Soleimani A. , Rasaei M. R. , Mavaddat Y. , Momeni A.
Published: October 2011

Horizontal wells with multiple fractures are becoming more prevalent in the Industry. They can especially beneficial in gas condensate reservoirs to minimize the pressure drop in order to reduce liquid drop-out and reduce the severe loss of well productivity and therefore lower gas recovery. Reliable evaluations of stimulation performance are required for field development planning. As such, pressure transients are often used, and can be successful, to observe and define the various impacting factors of stimulation, such as fracture length, conductivity, orientation, etc.

This project investigates the modeling and interpretation of pressure transient responses of multiple hydraulic fractured horizontal wells in gas condensate reservoirs using a numerical reservoir model with a focus on the existence of different mobility zone due to condensate dropout. Derivative shapes expected from hydraulic fractured horizontal well-test data are obtained using a 3D fully compositional model in gas condensate reservoirs below the dew point under various conditions. The numerical model is validated using an analytical solution and applied to a simple reservoir model. Complex reservoirs are then simulated and pressure transient response signatures are obtained. Sensitivity studies of important reservoir, well and fracture properties are performed and a result of each case is presented.

It was found that condensate dropout near the wellbore yields a well-test composite behavior; similar to what is found in hydraulically fractured vertical wells, but superimposed on a horizontal well behavior, which makes it much more complex. Furthermore a higher gas production will be achieved in a horizontal well with optimum number of fractures, fractures conductivity and fracture half length which may depend on formation and hydrocarbon characteristics.
Advancements in Drillstring Dynamics Modeling Deliver Performance Step-Change, Saudi Arabia
Authors: Al Reda Saeed , Juwaiher Hussain , Feroze Nouman , Karuppiah Venki , Wu Sean Xianping , Partin Uyen , Bits Smith
Published: October 2011

Drilling deep 16-in. hole sections in Saudi Arabia's gas wells is particularly challenging due to complex stratigraphy consisting of carbonates with interbedded hard stringers, abrasive sandstone, and dense dolomite. These hard/abrasive formations can cause high-axial and lateral vibrations, which have led to premature PDC bit damage. To combat these drilling performance problems, a holistic approach was undertaken to optimize bit design and the drilling system. This included a thorough analysis: Rock samples that matched the challenging formations were collected and laboratory tested to quantify the forces between the cutters and rocks in order to formulate relative rock removal rates. This information and that gathered from a test BHA—after operating for 24 continuous hours during which drilling parameters were monitored—was evaluated using an advanced dynamics model. This enabled improvements that resulted in an optimized bit design and drilling system.

This highly beneficial modeling technology is a comprehensive, 4-D, and finite element model, which accurately predicts the drilling system's performance from bit to surface and simulates the transient response of the entire system in time domain. Applicable for any drillstring configuration, the modeling technology is capable of providing performance information on specific BHA components: RSS, PDM, PDC/roller-cone bits, stabilizers, reamers, MWD/LWD, and other downhole tools. Such information includes: acceleration, velocity, forces, bending moment and displacement at any node along the drillstring. Using an advanced dynamics model enabled engineers, working in a virtual drilling environment, to make an extensive effort toward bit design improvements. The resulting bit design, BHA, drilling parameters, and their effect on instantaneous ROP, drillstring vibrations, and directional tendency were quantified and optimized.

This holistic approach significantly improved drilling performance in Saudi Arabia's problematic formations. The newly designed bit drilled an entire 16-in. section 5,219 ft from mid-Thamama to base Jilh Dolomite formation at an average ROP of 29.2 ft/hr and achieved the longest 16-in. PDC run in "deep casing design" wells. ROP was 18% faster than the previous best run in a similar application. The authors will outline the analysis, resulting cost reduction, and how applying advanced modeling technology improved drilling performance through the bit, BHA, and drilling parameter optimization.
Geomechanical Study for UBD Feasibility in the Northern Iraq Fields
Authors: Soroush H. , Gao H. , Qutob H. , Neil B. , Mahli Z. , Abalioglu I.
Published: October 2011

Successful underbalanced drilling (UBD) operations are strongly dependant on the understanding of in-situ stress condition in addition to rock mechanical properties. Wellbore integrity, which plays an imperative role in all the oil and gas operations, requires accurate geomechanical modeling and wellbore stability analysis. Borehole failure problems, which are very likly specially when drilling underbalanced, cost the petroleum industry several billions of dollars each year. Prevention of these problems requires clear understanding of the interaction between formation strength, in-situ stresses and drilling practice. Since in-situ stress and rock strength are not controllable parameters, adjusting the drilling practices, i.e. selecting optimal trajectory and bottom-hole pressure, is the common way to inhibit wellbore failure, which can be achieved by performing specialized geomechanical studies.

Drilling through some challenging formations in Kurdistan, has been always associated with several wellbore stability problems such as mud losses, borehole washout, stuck pipe, extra cutting/caving, and tight holes, which caused numerous nonproductive time to the drilling program and required drilling sidetracks in some of the wells. Review of the drilling reports and dual-caliper logs from 11 offset wells in the area revealed a huge amount of washouts in these formations. These events put a question mark on the feasibility of UBD in these intervals and required conducting a geomechanical modeling and wellbore stability study.

In this study, data from offset wells was analyzed to estimate the local in-situ stress magnitudes and orientations, in addition to pore pressure. The mechanical properties of the formations were evaluated using sonic, density, and gamma ray logs. A rock mechanical properties database and data management software was applied to correlate the calculated dynamic elastic properties to the most appropriate static stiffness parameters for a base case wellbore stability model and subsequent sensitivity analyses. 2D elastoplastic and 3D linear elastic models were used to back-analyze the borehole failures in the selected offset wells to verify and calibrate the geomechanical model.

Finally, an operating mud weight window was defined, and the optimum profile of the mud weight was recommended for drilling through each formations. This study showed that underbalanced drilling is feasible through the carbonate intervals, however, will encouter severe wellbore stability problems in the shaly and silty formations.
Can You Protect Your Motor Without Sacrificing Performance?
Authors: Guidroz Blair
Published: October 2011

Achieving balance between performance and longevity of drilling motors is a constant struggle. Operating above recommended parameters delivers higher Rates of Penetration (ROP) but can be too aggressive, causing accelerated component wear and potentially, premature failure. Conservative operation decreases the component wear but can be detrimental to drilling performance. A novel approach to controlling motor performance allows operators to operate at specified limits while preventing load spikes that damage motors.

Stalling is a problem that affects bearing loading, occasionally leading to driveshaft torsional failure, but more commonly causing power section damage in the stator, reported as chunking. Chunking occurs when the elastomer in the stator has reached the fatigue limit and small pieces break free of the profile. The output performance of the power section decreases as the effective area of power section is reduced and it becomes less efficient. Reduction in output performance decreases ROP and operators will typically push motors harder to maintain ROP, further accelerating the time to failure.

An innovative internal device prevents premature failure by limiting the amount of differential pressure applied across the motor. Excess pressure is relieved by porting fluid through the center of the rotor, bypassing the power section inlet. Rotational speed decreases as flow into the power section is decreased. The pre-determined relief point is adjustable to optimize motor performance for specific applications. Preventing motor damage delivers longer drilling hours with reduced unplanned trips.

Field testing of the device has resulted in a significant reduction in motor component damage. ROP improved and was consistent through the drilling program with the controlled and steady operation of the device. Cost per foot decreased as longer intervals were drilled per motor. This device gives operators a new tool to optimize motor performance.
First Dual-Target Horizontal Appraisal Well-Geosteering in Thin Siliciclastic Reservoir of the Mauddud Formation, Sabriyah Oil Field, North Kuwait
Authors: Ibrahim H. , Al-Awadi A. , Oyeyemi O. , Chimirala V.
Published: October 2011

Since, the discovery of the Mid-Cretaceous Mauddud formation in the Sabriyah and Rhaudhatain fields of North Kuwait, there has been an interest to systematically produce the thick (> 400 ft) carbonate-dominated section, which has a complex geological setting that influences the performance of these reservoirs. Several wells have been drilled in the past—deviated, vertical, and horizontal wells focusing solely on the carbonate-dominated reservoir section with little emphasis on the siliciclastic shoreface facies of the lower Mauddud formation.

The use of state-of-the-art real-time logging-while-drilling (LWD) data from the distance-to-boundary (DTB) resistivity mapping technique coupled with normal triple combo LWD formation evaluation log measurement and real-time pressure and mobility estimations provides insight into the lateral facies changes and the heterogeneity of the MaH reservoir layer for the first time.

The predominantly carbonate Mauddud formation stratigraphically overlies the greater Burgan member. It was deposited in a low-to high-energy shallow marine ramp setting. The high-energy facies at the base is punctuated with out-of-sequence siliciclastic influence marking the waning of the deltaic Burgan sand influx. The upper part of the Mauddud formation is a highly diverse suite of low-energy carbonate facies characterized by highly bioturbated and reworked massive beds of wackestone and packstone with few depositional textures. This section is overlain by the prograding clastic sediments of the Wara formation and capped by the extensive transgressive shale of the Ahmadi formation.

Well A (SA-0X05), the appraisal well, was planned to cut across all the Mauddud 10 reservoir layers and go lateral into the MaH reservoir with 100% NTG, thus yielding maximum reservoir contact (MRC) to evaluate this sand body for the first time. The results from porosity measurement validated the static model for this interval, and the pressure regime and mobility where inline with predicted values considering vertical variations. Lateral facies changes were observed showing coarsening-upward, clean-grained facies towards the base and the fine-grained glauconitic facies on top. Although an approximate20-ft thickness of sand was observed as a correlatable sequence from offset wells, in reality, geosteering revealed that the lower 15 ft of section was mostly distal in origin and changed to a more marine offshore facies below.
Using Integrated Geomechanical Study To Resolve Expensive Wellbore Instability Problems While Drilling Through Zubair Shale/Sand Sequence of Kuwait: A Case Study.
Authors: Azim Shaikh Abdul , Mukherjee Pritish , Al-Anezi Salah Ali , Al-Otaibi Basel , Al-Saad Badr , Perumalla Satya , Araujo Ewerton , Babbington Jeremy F
Published: October 2011

The Lower Cretaceous Zubair formation in Kuwait comprises oil-bearing sands intercalated with shale sequences. Historically, drilling into this formation presented major wellbore instability issues that include hole pack -off, stuck pipe and logging tools, high over-pull, tight zones while tripping, and severe hole washouts. These well problems have a significant impact on well costs and timeline.

Wells drilled in every orientation have experienced instability problems in this formation. Vertical wells have encountered major washouts and difficulties with wireline logging operations. Deviated wells have been even more unstable and often required sidetracks - greatly increasing well costs.

This paper analyzes these wellbore instability problems, including the failure mechanisms, and presents the actions taken to resolve them. A solution to these instability issues is presented, which was derived by building geomechanical models using well data, drilling problem analysis, core inspection, and core -based rock mechanical test results.

We used chemoporoelastic and anisotropic geomechanical models to simulate the behavior of the Zubair formation while drilling in vertical and deviated holes to understand the wellbore instability experiences.

Based on the analysis, changes in mud weight, reformulation of the mud system, and modified drilling practices were incorporated in the well plan of new high-angle wells. Success was achieved in drilling the wells and running the casing in this formation with deviations as high as 80°. The study helped to achieve a large reduction in indirect NPT due to wellbore instability. This experience is also a key learning and input for designing future complex trajectories. It is expected that a major measurable impact in the form of smoother operations and optimized well cost will occur during the drilling campaign based on recommendations from this analysis.
Integrating Petrophysics, Geomodeling and Advanced Well Placement Technology for Efficient Field Development
Authors: Barbosa Jose E. , Ali Arfan , Hern Caroline
Published: October 2011

This paper describes how petrophysics and geomodeling, integrated with advanced well placement technology, can be used to optimize well trajectory in horizontal well drilling operations. We have simulated a 3D facies model of the Mulichinco Formation within a hydrocarbon field located in the Neuquen Basin (Argentina) by taking into account petrophysical, geological and geophysical data. The integrated approach allows to analysis of possible drilling scenarios and to prepare contingency plans in time for maximizing hydrocarbon production. We have also compared our simulated 3D models with the LWD data of an existing horizontal well in order to optimize well placement in real time and to reduce risks associated with drilling in non-pay zones. The results presented in this paper are complementary to the prior information available in the studied field from other conventional techniques.

Initially we tested the new approach on four existing horizontal wells, targeting shallow marine sandstones within the upper Mulichinco Formation (Valanginian), where an excellent match was observed between the predicted and actual facies encountered. We subsequently applied the technique by taking into account the data from 31 wells in the field. This new approach can be used to optimize well placement in any depositional environment (both onshore and offshore) by highlighting the geosteering hazards and ensuring that the wellbore is drilled inside the "sweet spot" and away from non-productive layers. The new approach and the associated horizontal well data also improve understanding of the distribution of facies and their geometrical configuration.
Characterization a Self-destructing Filter cake by Using Computer Tomography
Authors: Elkatatny S. M. , Rostami Ameneh , Nasr-El-Din H. A.
Published: October 2011

Drilling long horizontal and multilateral wells with very low drawdown makes efficient cleaning and stimulation treatments very challenging. None of the conventional chemical cleaning methods can overcome problems for filter-cake removal in long horizontal and maximum reservoir contact wells because of limitations such as the complex geometry of wells, nonuniform chemical distribution, low contact between cleaning fluids/filter cake, and high chemical reaction rate, especially at high temperatures.

All of these challenges lead us to develop a new system of filter cake removal method that addresses several key problems inherent in the removal of drilling fluid filter cake, cleaning, and stimulation treatments of horizontal and multilateral wells. This system is a water-based drilling fluid that is weighted with calcium carbonate and has a mixture of solid-acid precursor and particulate solid-acid reactive material. This fluid has both functions of drilling and completion and can reach total depth of MRC wells. It has the ability to effectively stimulate the whole horizontal sections after drilling.

Previous work by the authors on this self-destructing drilling fluid system resulted in obtaining the best formula based on the original water-based mud (SPE 136400). High temperature high pressure filter press results (SPE 139087) showed high filter cake efficiency in cleaning the filter cake. Unlike the conventional reactive acids such as HCl, the slow reaction kinetics ensured good distribution of the generated acid across the filter cake.

The objective of this study is to determine the homogeneity of the self-destructive filter cake. Image J software and Grabit software combined with CT scan results were used to determine the filter cake properties such as porosity, permeability and thickness of the self-destructing filter cake system.
An Energy Based Comparison of Alternative Drilling Methods
Authors: Elahifar Behzad , Esmaeili Abdolali , Prohaska Michael , Thonhauser Gerhard
Published: October 2011

During the last decades, non-conventional solutions for more economical well bore drilling have been investigated. Big research efforts and budgets have been spent on alternative drilling methods; such as laser drilling or jet assisted drilling. Simplified assumptions predicted a big future for such technologies. However, to get a better and more realistic picture of the feasibility of such unconventional ways to drill rock, the ability to apply them in field scale applications needs to be questioned. In this paper a holistic energy approach to evaluate drilling alternatives is proposed.

To evaluate the energy balance of the drilling system the amount of energy generated, e.g by the rig at surface, needs to be put in comparison with all system energy consumption to lead to an effective energy available to destroy rock at the bottom of the hole. To test this concept a small scale laboratory setup is used to compare different drilling methods under similar conditions.

This paper presents a systematic approach using an energy concept to compare alternative drilling methods on a laboratory scale. In this first approach laser assisted spallation and conventional drilling were compared. As a by-product, also the optimum mode for spallation drilling, continuous versus pulse wave, will be presented.
Positive Displacement Motor Innovation Drives Increased Performance with PDC Bits in Unconventional Plays
Authors: Azizov Azar , Davila Wilfredo , Nnanna Obi , Rizen Andrej
Published: October 2011

The introduction of new, wear-resistant polycrystalline diamond compact (PDC) bit cutter technology in recent years has dramatically increased the demand for increased torque output from the positive displacement motor (PDM). The commercial introduction of pre-contoured (i.e., equidistant rubber thickness) stators in 2000 solved the theoretical technical challenge of developing very high torque output in a PDM. Yet, in cost-sensitive, land-based drilling markets where conventional power sections are still a major factor, the requirement for traditional motor power section construction restricted the rate of penetration improvements.

Recent developments in the chemistry of the standard stator elastomer have enabled a step-change improvement in the performance and durability of the power sections in PDMs. This premium elastomer, manufactured in conventional stator cans, can generate higher differential pressure and subsequently more torque, while achieving increased durability, even in some of today's oil-based drilling environments. This higher level of torque and increased downhole durability is ideally suited for the increasing toughness and aggressiveness of today's premium PDC bit. This paper will review in detail this innovative motor technology, describe how it enables reaching higher performance levels, and present several case histories illustrating this performance enhancement.
Development and Optimization of PDC bits for Rotary Steerable Systems through Unstable Formations
Authors: Portillo Oscar , Bahlany Salah , Agudelo Gloria , Alvarez Octavio , Al- Marzooqi Ali
Published: October 2011

Directional drilling in the build up section at North Oman Field in the Sultanate of Oman is challenging because of highly intercalated and unstable formations. The formation consists primarily of soft to medium hard limestones, dolomites inter- bedded with anhydrite, and a thick layer of unstable shale that forms the cap-rock of the targeted reservoir. The field development plan (FDP) specifies drilling long horizontal wells with two casing strings and a liner, and requires the reservoir section to be placed within the top meter of reservoir rock. Consequently, it is critical to land inside the top meter of the reservoir. The lack of directional control throughout the soft intervals, high dip angles in some of the formations, and the short vertical section from surface to landing point requiring BUR of 5 to 6 degrees/30mts created complications in drilling the build section. With these elements, optimum directional tools steerability is necessary to achieve the well objectives.

To overcome these challenges, the operator and drill Bit Company developed an optimization process to design a polycrystalline diamond compact (PDC) bit to use with point-the-bit rotary steerable systems (RSS). The optimization process included increasing the bit steerability and stability to increase the rate of penetration (ROP). This challenge required the development of a new PDC technology with optimized drilling practices and a reliable drive system. Specific bit design algorithms were incorporated with a new bit gage configuration, and drilling simulation software was used to optimize bit cutting structure design in the directional drilling environment. Significant bit design improvements were achieved. Going through field testing, drilling parameter evaluation and optimization, an 8½-in PDC bit design was created that established benchmark performances in the North Oman Field field.

The successful development of the PDC bit with the RSS system enabled record bit runs in the build sections, which were drilled in accordance with the FDP with significant ROP improvements compared to conventional motor. This paper reviews the bit design and optimization process that helped to improve the drilling performance and hole geometry, reduce rig days, and enable early delivery of the wells in the challenging Sultanate of Oman drilling environment.
Progression of Offshore Drilling Safety Culture through Smart System, Experience in South Pars Gas Field, Phase 12
Authors: Rahimi R.
Published: October 2011

The PETROPARS Drilling department has developed a safety culture via SMART system in its drilling operations that employs a high level of behavior-based observations to help instill a broad based understanding of safety and hazard recognition. Senior management developed safety principles, but the day-to-day incorporation of the safety principles are coordinated by the workers themselves. This has led to a progressive improvement in safety results as the program and culture has matured.

The majority of the subsurface work is conducted on offshore jack-up drilling rigs by contract drilling personnel and service companies. In order to establish the desired safety culture, core safety principles were established and communicated by management. Then safety leadership training was provided to all key workers to gain understanding and commitment. Finally a behavior-based safety observation program was adopted and modified to fit this work environment. This behavior-based program has implemented through SMART system or (See Monitor Act Reinforce Track) that covered all aspects of the offshore drilling operation. The evolution of worker participation has been far greater than originally envisioned.

This paper demonstrates that safety can be improved with direct participation of the workforce in a behavior-based observation program according to PETROPARS achievement.
Feasibility Study of Casing Drilling Application in HPHT Environments; A Review of Challenges, Benefits, and Limitations
Authors: Radwan Amr , Karimi Moji
Published: October 2011

HPHT wells present many economic, technical, operational and HSE challenges. Casing Drilling is introduced as a potential alternative method for drilling HPHT wells. The benefits and limitations of Casing Drilling are investigated in this study in correlation with the current HPHT challenges.

The operational mud weight window can be widened beyond the traditional trip margin through the well-known Plastering/Smear Effect of Casing Drilling. Moreover, many mud challenges in HPHT wells can be eliminated including static and dynamic barite sag, drilling mud deterioration under static conditions, heavy solids content and wellbore cleaning inefficiency. The wells drilled with casing are more gauged and the quality of the cement sheath is better. Casing drilling can provide better protection for logging tools and allow many conventional tools to be used without any modification.

Casing Drilling can significantly reduce the cost of drilling through harsh environments. Additionally, drilling hazards of HPHT wells will be minimized because Casing Drilling can eliminate drilling problems such as stuck pipes, well control incidents, surge and swab effects, wellbore instability, and lost circulation. However, to ensure that this technology can present the previously argued benefits, there are some challenges that need more studies. Most of these issues are related to the manufacturing features of the materials (e.g., dope channels and substantial thermal expansion) and excessive loads (e.g., wear, torque and drag). The recommendations suggested in the study can help in limiting and overcoming these challenges.

The proposed methodology can potentially take drilling HPHT wells to a new level and also pave the way for xHPHT environment. Casing Drilling opens a new window to the current technologies and tools in HPHT wells without significant modification. Also it is a potential option to eliminate economic, operational and HSE challenges in drilling HPHT wells.
Understanding and Eliminating Drill String Twist-Offs by the Collection of High Frequency Dynamics Data
Authors: Raap Constantijn , Craig Andrew , Perez Daniel
Published: October 2011

Drill string twist-offs are an expensive problem to the oil and gas drilling industry. With ever increasing rig and operating costs, there is an increased focus to avoid twist-off related expenses, such as: costs associated with time required to trip out of hole and replace the failed components, the cost of repair or replacement of failed equipment, fishing operations and possibly the cost of side-tracking. Oil and gas operators attempt to prevent drill string failures by optimizing the drill string and trajectory designs. Drill string manufacturers aim to engineer drill pipe and tools with ever increasing strength properties and maximum fatigue resistance. In addition to this, drilling contractors and service companies have extensive inspection programs to avoid failure. Despite these efforts, twist-offs remain an important problem for a large number of drilling applications. Recent research and analyses suggest that the majority of drill string failures are caused by fatigue. Since the root cause of a fatigue failure cannot always be identified from surface drilling parameters or laboratory analysis, the evaluation of drilling dynamics data is essential for understanding the cause of a twist-off.

This paper will present several case studies from the North Africa region to illustrate the important contribution of drill string vibration on fatigue-related failures. In all cases, high resolution dynamics recorders were incorporated into the BHA, or drill string, close to the location of the twist-off. Analysis of the dynamics data revealed that the drill string was exposed to severe lateral vibration prior to the twist-off events. Furthermore, the observed vibration was the major contributor to the sustained fatigue due to the resulting severe shock loading and increased bending stresses generated during vibration. The paper will also present mitigation practices or changes that were implemented based on the drilling dynamic analyses as well as potential solutions for the remaining case studies. Generally, these solutions are significantly more cost effective than the traditional approaches of reducing twist-offs such as: increased frequency of inspection programs or enhanced mechanical properties on connections and drill strings.
Successful Auto Gaslift using Intelligent Completion Boosted Oil Production – A Case History from Petroleum Development Oman
Authors: Peringod Chandran , Al-Ruheili Sharifa , Kerecin Zeljko , Sonti Kartik , Sukkestad Tor
Published: October 2011

Field B is undergoing implementation of an accelerated development plan and around 40 wells have been drilled so far. Due to the volatile nature of the crude and high GOR, gas recycling was identified as the reservoir pressure maintenance strategy. There are 4 gas injectors in the field injecting into two reservoirs. As per the original development plan, no artificial lift was envisaged and model results showed sustained natural flow from the well. However, after drilling and completing the wells, it was found that sand connectivity and continuity were far more complicated than expected. This resulted in depleting the reservoirs in certain compartments thus requiring some form of artificial lift. Further, this field will be undergoing a gas blow down project from 2015 onwards, and the challenge to the Well & Reservoir Management Team was to maximize recovery before gas blow down.

A series of options were considered and gaslift was selected as the most viable artificial lift mode. Lead time for the conventional gaslift and the cost associated with special piping materials were adversely impacting the plans and an innovative idea of auto gaslift was proposed as an alternate to conventional gaslift. Accordingly, Well #XX was selected for application of this technology. Auto gaslift uses high pressure gas from a gas reservoir admitted into the tubing using an intelligent completion & special ICV with gas trim and straddle packers. A down hole pressure gauge installed on top of the packer will assist in tuning the choke settings during auto gas lifting. Based on the success of this well, 5 more wells were re-completed with Auto gaslift technology resulting in increasing the production by 50% from the field. Currently, this technology is being evaluated for other fields in the company's assets.

This paper explains the technology of Auto gaslift, details of intelligent completion used in the wells, results obtained, gaslift optimization, lessons learned and way forward for artificial lift in other fields with similar reservoir conditions.