bluuebunny/crossref_metadata_2025 huggingface dataset:
Management: The Evolution of Outsourcing and Insourcing in Oil and Gas Accounting
Authors: Adams Gary A. , Youdal Sam
Published: February 2015

With fluctuating oil prices, the oil and gas industry is constantly looking for ways to reduce costs. Several companies outsourced their accounting operations in the mid-1990s, but many are now rethinking their decisions to take this plunge.

Many companies have evolved their thinking about back-office outsourcing. In the past, running unique, efficient back-office functions, such as accounting, human resources, or customer care, was considered to be a competitive advantage. However, most companies sustained large, costly departments that developed and maintained in-house proprietary systems. These systems were typically inefficient, comprising loosely connected processes. The introduction of enterprise resource planning (ERP) systems in the early 1990s made an efficient back-office operation a prerequisite. By design, ERP systems impose common processes and link functions that once may have been separated. With common processes and data in place, many set up centralized shared services to gain economies of scale. Companies were able to focus more on front-office operations, where competitive advantage is truly achieved. Subsequently, several firms took the next step by outsourcing their back-office operations to third-party companies. These outsourcers handled similar back-office operations across many companies, presumably achieving even greater synergies and cost savings for their customers.

Similar trends were seen in the US oil and gas industry, particularly in oil and gas production revenue accounting (PRA). As in other industries, oil and gas companies also once considered an internal, streamlined accounting operation as a competitive advantage. Most oil and gas companies developed and maintained inefficient in-house processes and systems to handle the vast array of functions that make up PRA. As oil and gas companies searched for ways to reduce costs in the 1990s—to counter fluctuating oil and gas prices—back-office accounting was considered to be "low-hanging fruit." Many also found that ERP systems improved accounting data accuracy and decision making and reduced costs. Production and revenue activities within the US oil and gas industry are complex and can vary significantly, making synergies more difficult to achieve. Production and revenue functions include land management, contracts, pricing, and revenue distribution to interest and royalty owners. In this environment, the skill sets needed to understand and navigate through regulations and laws are unique, and often differ significantly based on geography. ERP systems were designed to handle these complex requirements (Fig. 1).
Overview: Knowledge Management and Training (December 2007)
Authors: Ellul Ivor
Published: February 2015

The topic of knowledge management has matured considerably over recent years, evolving from abstract discussion about the translation of raw data into useful information on to knowledge while presenting an exposé of the differences between explicit and tacit knowledge. These dialogues, more often than not, lacked cohesion as well as a clear impression of the effect on the industry's bottom line.

In reviewing the various papers for this year's feature, I have to remark about the superior quality and high degree of relevance of the various publications. One can witness a foundation of data acquisition and management in a continuum, which spans from the large volumes of data that comprise the static domain of the shared Earth model to the capacity to collect data on a continuous basis along the full profile of the wellbore. The latter is a clear demonstration of the great strides in technology made by the providers of data-gathering systems.

Until recently, many knowledge-management initiatives were hindered by an environment that was unable to make immediate and efficient use of all the data being acquired to benefit the operation of the asset. A mainstay in the downstream operation of refinery and pipeline systems, the upstream E&P industry has evolved slowly in accepting the value of real-time data. Clearly, we are now at an advanced stage of integration of technology and information that does, indeed, drive decision making on a continuous basis.

Coupling the advances described above with the ascribing of value to specific information provides added capability in making decisions that are bottom-line driven in an industry that depends increasingly on marginal assets as we focus on sustainability of current and future reserves. The papers featured this month provide an interesting wealth of information on the state of play of data-gathering technology, integration initiatives, operational deployment of digital oilfield environments, and the use of mentoring as a means of capturing and retaining knowledge. These are all excellent ingredients in a recipe for the continuing success of integrating knowledge management into mainstream E&P operations.

Knowledge Management and Training additional reading available at the SPE eLibrary: www.spe.org

SPE 106916 "From Sensors to Models to Visualization—Handling the Complex Data Flow" by Ø. Kolnes, SINTEF Petroleum Research, et al.

SPE 103287 "Sustained Competitive Advantage Through Structured Mentoring" by G. Arango, SPE, Hughes Christensen, et al.

SPE 108175 "Value-of-Information Applications in Unconventional Resource Plays" by Patrick E. Leach, Decision Strategies, et al.
Your SPE: Developing the SPE Partnership in Russia
Authors: Roodhart Leo
Published: February 2015

President's column

After a fascinating trip to China, which I wrote about last month, the next stop on my global travels was Moscow. The local members were looking forward to the forthcoming SPE Russian Oil and Gas Technical Conference and Exhibition, where up to 3,000 delegates were expected, more than double the numbers two years ago when the first event was held.

I am a strong advocate of diversity among SPE members, ultimately to develop a richer and stronger society. We need to be mindful of different cultures and behaviours and discover ways to reach mutually acceptable solutions. For example, it is essential to understand something about the Russian culture in order to engage in a meaningful discussion about SPE, business, or life in general. Certain SPE values and principles, such as volunteerism, impartiality, non-commercialism and free exchange of information, are not as well understood in Russia. Indeed, I have been told that there is no Russian word for volunteerism—just as there is no Dutch word for embarrassment, so I was able happily to continue conversations that others might find awkward.

During my stay, I met with Moscow Section officers and senior personnel at Lukoil (Mr. Ravil Ulfatovich Maganov, First Vice President), Russneft (Mr. Alexander Ledonidovich Korsik, Chairman of the Board), Rosneft (Mr. Alexey Kuznetsov, Vice President of Innovation), Statoil/Hydro (Bengt Lie Hansen, President), Shell (Frank Denelle), Gazprom Academy of Technological Sciences (Prof. Boris Alexandrovich Nikitin, President), Schlumberger (Maurice Dujolle), and Weatherford (Mr. Kamil Zakirov, Vice President for Russia & CIS). All companies welcomed SPE's presence in Russia and promised to support our activities. Lukoil has purchased a subscription to the SPE eLibrary. Some companies plan to award their staff SPE membership in recognition of professional achievement—SPE membership will be seen as a privilege and an honour. It became clear to me that quality rather than quantity is the key to membership recruitment, focusing on people who see the benefits of becoming part of an international organization. These people are likely to be aged 40 and under and are likely to have some fluency in English.

For some Russian members, however, particularly the older ones, SPE really adds value only if everything is translated into Russian. All meetings, workshops, and conferences are equipped with simultaneous translation, which allows for the exchange of information between Russian presenters and their English-speaking counterparts and vice versa. This means that the SPE Russian Oil and Gas Technical Conference and Exhibition, for example, can accommodate an international line-up of speakers. And, SPE has just launched a bi-monthly online Russian-language newsletter, called SPE Review: Russia and the Caspian, containing some of the excellent Russian papers presented at various SPE events in recent years. All members in Russia and any Russian-speaking members else-where will benefit from access to this information.
Interval-Control Valve Meets Deepwater, HP/HT Needs
Authors: JPT staff _
Published: February 2015

Technology Update

As operators push into new, more demanding environments in the search for hydrocarbons, technology providers have stepped up efforts to design downhole equipment to meet the challenges. Nowhere is this scenario more evident than in deepwater settings at depths beyond 7,500 ft, where pressures and temperatures can be extremely high and often render completion equipment ineffective.

A durable interval-control valve (ICV), designed especially for deepwater and high-pressure/high-temperature (HP/HT) conditions, has been developed recently by WellDynamics (a Halliburton company) as a key addition to the company's suite of intelligent-completion technologies. A core component of an intelligent-completion system, an ICV enables the control of well inflow or injection downhole, at the reservoir, without physical intervention. Operators, by this means, are able to optimize production and improve recovery (Fig. 1).

The inaugural installation of the valve, called the HS-ICV, was recently in progress at the StatoilHydro Snorre B complex and slated for completion while JPT was at the press. Additional installations are planned at the operator's Gøya and Tyrihans assets. StatoilHydro has been closely involved in the design and qualification of the new ICV.

A 15,000-psi version of this ICV, designed specifically to meet HP/HT needs in the Gulf of Mexico, is now being developed for a major operator. Currently, valve development is in the prototype stage, with qualification testing slated to conclude by mid-2009.

ICV Design and Operation

The ICV technology was developed with three goals in mind.Reliable performance in HP/HT conditions, encompassing temperatures up to 330°F and pressures up to 15,000 psiCompatibility with existing downhole-control and incremental-positioning systemsEnablement of closed-loop reservoir optimization

The ICV is actuated hydraulically and operated remotely from the surface by means of downhole-control-system technology. The valve design incorporates optional position sensors that, in conjunction with permanent monitoring systems, provide real-time feedback on the valve position.

The ICV also has been designed optimally to allow bypass of multiple hydraulic- or electric-control lines, without compromising the valve rating, and thus enables smooth, reliable ICV installation in complex, multizone applications where there are multiple control lines.

Metal-to-Metal Sealing

A key design feature of the ICV is a proprietary, debris-tolerant, metal-to-metal seal, which enables the valve to unload at differential pressures of up to 5,000 psi. The sealing system enables life-of-well performance in the most demanding environments and features a secondary thermoplastic wiper/seal, which eliminates the potential for seal damage caused by downhole debris. The sealing arrangement has been rigorously tested and qualified at low and high (15,000-psi) static pressure differentials, providing the basis for developing future, high-pressure versions of the valve.
High-Speed Wired-Drillstring Telemetry
Authors: Bybee Karen
Published: February 2015

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 113157, "High- Speed Wired Drillstring Telemetry Network Delivers Increased Safety, Efficiency, Reliability, and Productivity to the Drilling Industry," by M. Hernandez, SPE, D. MacNeill, SPE, and M. Reeves, SPE, IntelliServ, and A. Kirkwood, S. Lemke, J. Ruszka, SPE, and R. Zaeper, SPE, Baker Hughes, originally prepared for the 2008 SPE Indian Oil and Gas Technical Conference and Exhibition, Mumbai, India, 4-6 March. The paper has not been peer reviewed.

High-speed wired drillstrings enable two-way wireline communications between bottomhole assemblies (BHAs) and surface systems. Compared to even the most advanced mud-pulse telemetry (MPT), this new capability allows reliable communication with rotary-steerable systems (RSSs), measurement-while-drilling (MWD) systems, and logging-while-drilling (LWD) systems at data rates tens of thousands of times faster than before. The full-length paper describes the system development and discusses in detail the advantages immediately attainable when complete, memory-quality, drilling and evaluation data are provided instantaneously at surface while drilling.

Introduction

In 1964, a mud valve was suggested to transmit data up the mud column. In the 1970s, transmission of data from tools in the BHA to the surface was achieved. This system, MPT, used pressures pulses created in the downhole tools and transmitted through the continuous column of drilling fluid to surface where they were detected by use of a pressure transducer and then decoded. This revolutionized the directional-drilling industry by providing the directional driller with real-time information for determining the geometric position of the wellbore and steering-system performance. This resulted in significant gains in directional-drilling efficiency and accuracy while simultaneously reducing risk.

Companies soon recognized the value of MPT and developed formation-evaluation devices within the BHA. Transmission of these data to surface in real time allowed the well trajectory to be referenced to geological features. Initially, natural gamma ray (GR) and basic resistivity devices were introduced, and this soon expanded to an ever-increasing range of sophisticated devices. These devices provide a wide range of data sets, equivalent to wireline-acquired data in quality but acquired in real time very soon after the formation was drilled. To take full advantage of these measurements to influence decisions in real time, a dramatic increase in data-transmission rates from downhole to surface was required. MPT technology continuously improved to allow transmission rates of up to approximately 20 bits/second (bps) in practice. This, however, still fell short of the transmission rates required to maximize real-time use of the latest LWD systems.
Efficient Conceptual Design of an Offshore Gas-Gathering Network
Authors: Denney Dennis
Published: February 2015

This article, written by Technology Editor Dennis Denney, contains highlights of paper SPE 116593, "Efficient Conceptual Design of an Offshore Gas-Gathering Network," by M.J. Watson, SPE, N.J. Hawkes, P.F. Pickering, SPE, Feesa, and L.D. Brown, ConocoPhillips, prepared for the 2008 SPE Asia Pacific Oil & Gas Conference and Exhibition, Perth, Australia, 20-22 October. The paper has not been peer reviewed.

Offshore gas-gathering networks require large capital investments in wells, subsea equipment, pipelines, and compression systems. A thermal/hydraulic integrated-production model (IPM) was used to evaluate many design options for such systems. IPM calculations were performed to establish the phasing of drilling, field development, and compression necessary to sustain required gas-delivery rates.

Introduction

Conceptual design in the upstream industry can confirm if a project concept is economically feasible and then directs later design stages toward an optimal design. Many options must be analyzed to find workable solutions and highlight the potential of new technologies. With new developments in harsher environments and with fluid properties becoming more difficult, the possible use of a traditional tieback solution decreases and the need for new technologies increases. Consequently, a multidisciplinary approach to concept design is beneficial because disciplines such as drilling, flow-assurance, process, and corrosion engineering may influence feasibility as much as traditional subsurface factors. The difficulty is keeping the disciplines aligned with each other. This is particularly difficult during conceptual design when the rate of change is usually at its greatest.

The system of interest is a large gas-gathering network with multiple drill centers. Although common, these fields are in a region with extreme ambient-temperature conditions where the annual window for drilling is comparatively short. A key objective was to investigate the development plan for offshore facilities within which the drilling schedule could be "stretched out" while maintaining the required gas-production rates.

The model for this study is shown in Fig. 1. It consists of eight small gas reservoirs (DC-1 through DC-8), individually tied back to an offshore processing and compression facility on a larger reservoir (the Hub), which is approximately 150 km from an onshore processing facility. Production commences with wells at the Hub. When production from the Hub field declines below the capacity of the processing facility, satellite fields are brought on successively. When compression is required, the wells are switched from a high-pressure (HP) to a low-pressure (LP) manifold in a manner to meet production targets and minimize compression horsepower.
Comments: The Industry and Climate Change
Authors: Donnelly John
Published: February 2015

Editor's column

Energy companies will keep a close eye on this month's global summit on climate change in Copenhagen, hoping to get some direction on how global environmental policies will affect the industry for years to come.

More than 100 countries will meet to negotiate a world-wide framework for tackling climate change and create a successor treaty to the Kyoto Protocol. Although the causes and extent of climate change may be controversial, there is no doubt that public policy is moving in a direction that will burden industry with more public scrutiny, more reporting requirements on emissions and other data, and more costs related to reducing emissions. The situation is similar to the 1970s and 1980s in which the oil industry suddenly faced a slate of new health, safety, and environmental regulations. "The pressure to reduce global greenhouse-gas emissions is becoming a defining feature for the energy sector," says Robert LaCount, a senior director at IHS/Cambridge Energy Research Associates (CERA) and head of their Climate Change and Clean Energy Group.

An agreement at the summit could pave the way for rapid development and use of carbon capture and storage technology, or could spur the process of developing a global cap-and-trade scheme. A cap-and-trade market would set a carbon emissions limit for companies or countries but would allow them to buy allowances from others that were under their cap. Many transportation sectors favor this approach in lieu of carbon taxes.

But it is becoming clear that changes will need to be made on both the supply and demand side of the equation no matter how aggressive new emissions targets are. On the demand side, limits may be placed on fossil fuel use and there will need to be aggressive investment in improving energy efficiency. On the supply side, meeting emissions targets would appear to support more use of nuclear, renewables such as wind and solar, biofuels, and implementing carbon capture and storage technologies. Limits on coal use by utilities could greatly increase natural-gas use. In short, the world will require more energy at a much-reduced impact on the environment.

Going forward, oil and gas firms will be required to assess their "carbon footprint" and report those results to stakeholders and regulatory bodies, IHS/CERA believes. Stakeholders will increasingly demand, and governments will require, more quantitative and less qualitative sustainability reports from oil companies. Environmental policies will become a business driver, informing strategy and investment decisions, and environmental issues will become more important financially as greenhouse-gas emissions become an asset or liability in cap-and-trade programs. Firms will need to track emissions, manage emission-reduction targets, assess performance, report to regulatory agencies, and evaluate the operational impact. Although there is no consensus on policy as of yet, oil and gas companies should prepare for a more complex future.
IOCs, NOCs, and Service Companies: An Emerging Innovation Ecology
Authors: Karanjikar Mukund , Jakubenas Kevin
Published: February 2015

Guest editorial

The collaboration landscape for new oil and gas projects has changed significantly in the past several years because of the need to bring massive production projects on line in shorter times. No company can do it alone. A triangular involvement of international oil companies (IOCs), national oil companies (NOCs), and service companies has become a necessity.

The driver for this new collaboration landscape is the scope of challenges facing new projects, including project locations, country policies, capital, technology, and the ability to manage the production. In the era of easy oil, location and capital were the prominent reasons for collaboration. But with today's harder-to-access oil, technology plays a more pivotal role in the success of projects. The IOC/NOC/service company collaborative landscape presents a set of opportunities as well as challenges for technological development. Collaboration is now an integral part of technological innovation. Productive collaboration for innovation requires an ecology unlike one that oil and gas industry has previously seen.

Partnering for Innovation

Partnering for innovation is vastly different from partnering for capital or resources. Capital and resources exist and can be quantified using well-accepted methods; technological innovation is a promise of a better future based on ideas. Innovation is a matter of creating something that does not currently exist. Collaborative innovation is getting multiple groups to work toward a goal in which the path is unknown and discoveries may not occur on schedule. A vast amount of knowledge and ideas has to change hands before a useful piece of technology can be deployed. Learning occurs everywhere: in the field, glass-front offices, world-class laboratories, or at pilot rigs.

To understand the various skills required, it is worth examining more closely the respective roles of IOCs, NOCs, and service companies in the current innovation ecology.

IOCs.

These have been the leaders in the "ability to produce oil." The know-how of more than 100 years in managing resources around the world resides within these companies, and they have created many of the game-changing technological breakthroughs that enable today's oil and gas production. IOCs also have a very strong global intellectual-property (IP) portfolio that spans the entire value chain from exploration to distribution. Their manufacturing ability is a unique strength for future innovations as downstream knowledge is leading to innovations in the upstream development of challenging resources.

Service Companies.

In today's world, it is impossible to produce without the involvement of service companies. Service companies originated in operations but now successfully manage technologies and have been responsible for numerous technological innovations. In the process, these have managed to develop a strong IP portfolio with respect to their core competencies.
Techbits: Sustainable Development of Natural Gas Explored in Trinidad
Authors: JPT staff _
Published: February 2015

Techbits

SPE's Applied Technology Workshop (ATW) titled "Natural Gas: Development in a Sustainable Manner" and held earlier this year in Port of Spain, Trinidad, served as a catalyst for discussions about the prudent development and use of the natural-gas resources of Trinidad and Tobago.

Sustainable development, defined as development that meets the needs of the present without compromising the ability of future generations to meet their own needs, was at the forefront of each session of the workshop. Presenters shared both local and international experiences on a variety of topics across the natural-gas value chain, from upstream to downstream, and highlighted sustainable solutions for long-term development of the resource.

Growing Global Gas Demand

BHP Billiton's Nigel Sookdeo, cochair of the ATW's technical program, began with an overview of the importance of natural gas, stressing that it will continue to be a key energy source for the downstream industrial sector and power generation for decades to come. He pointed to estimates from the US Department of Energy and others that natural-gas demand is expected to increase from its present rate of 106 to 158 Tcf per annum by 2030—an average increase of 2% per year. This demand growth is partially tied to the relative cleanliness of natural gas vs. other fossil fuels in terms of lower CO2 emissions—a factor that is expected to become more important for regulatory agencies charged with enforcing ever-stricter standards for greenhouse-gas emissions.

For Trinidad and Tobago, natural-gas production is at approximately 4 Bcf/D, which is 85% of the country's daily BOE production and makes it the world's 20th-largest gas producer. Gas and the rest of the upstream sector generate up to 55% of the country's revenue in the form of petroleum taxation. The country has monetized its vast gas resource by developing a large downstream petrochemical sector in the form of feedstock for local petrochemical and power plants, and for liquefied-natural-gas (LNG) export. Trinidad and Tobago is now one of the largest producers of methanol and ammonia, and the fifth-largest exporter of LNG.

In terms of local consumption, approximately 60% of the total natural gas produced is used for LNG production and export, and 15% each for ammonia and methanol manufacture. Despite the global financial crisis of the past year, further expansion of the downstream petrochemical sector is planned—including new plants for aluminum, gas to liquids, polyethylene, and polypropylene—all requiring natural gas as a feedstock and fuel source. The projected increase in demand is forecast at 550 MMscf/D, which translates to a reserves replacement of 1.5 Tcf required annually to feed this demand. Recent reserves replacement has been on average only 0.75 Tcf per annum.
Massive Milestone Qatar LNG Project Goes Forward
Authors: Sheehan John
Published: February 2015

Qatar Petroleum and ExxonMobil officially inaugurated Train 6 of their Rasgas liquefied-natural-gas (LNG) project in Qatar in late October, boosting plans to produce 77 million tonnes per annum (t/a) of LNG from the Middle East state by the end of the decade.

The train, which has a capacity of 7.8 million t/a, is one of the largest in the world and brings the overall LNG production capacity of RasGas to 28.5 million t/a. The milestone, which was marked by an inauguration ceremony on 27 October, was the result of a long-term development project involving major offshore and onshore construction, subsurface drilling, and engineering works.

Train 6 is one of a new generation of LNG "mega trains," which are each capable of producing 7.8 million t/a of LNG. Its startup is expected to be followed by the coming on stream of Train 7, which also has a capacity of 7.8 million t/a, before the end of this year.

The two new mega trains have been built at the RasGas site adjacent to its existing facilities at Ras Laffan Industrial City in Qatar. Both Trains 6 and 7 will be supplied with natural gas from Qatar's giant North Field, which is estimated to contain in excess of 900 Tcf of natural gas.

The startup of Trains 6 and 7, which are owned by Ras Laffan Natural Gas Company 3 (in which Qatar Petroleum has a 70% share and ExxonMobil 30%), will allow RasGas to begin supplying LNG to new customers around the world, including the US and Asian markets.

"Working in partnership with Qatar Petroleum, Ras Laffan 3 Train 6 represents yet another technological milestone that will help supply the growing global demand for clean-burning natural gas," said Neil Duffin, president of ExxonMobil Development Company. "Advanced technologies, strong project-execution skills, and economies of scale have reduced the cost of producing and transporting LNG, thereby extending our ability to bring LNG to more people around the world."

The large production capacity is a big step up from the 4.7 million t/a that RasGas Trains 3, 4, and 5 each produced.

"Train 6 is a clear demonstration of RasGas’ confidence and ambition," said Hamad Rashid Al Mohannadi, managing director and chief executive officer of RasGas. "It is time to recognize the skill, determination, and sheer hard work of everyone involved in delivering, safely and within budget, a very successful project outcome.

"At this time, special recognition must also be made to our shareholders, Qatar Petroleum and ExxonMobil, who continue to demonstrate commitment and support each step of the way. Together, we can look to the future with great confidence."

Al Mohannadi said that every aspect of the new train had to be scaled up, from pipeline diameters to power supply and everything in between. "RasGas’ project teams embraced these challenges and delivered excellent results," he added.
Bit Selection Using Mathematically Modeled Indices
Authors: Bybee Karen
Published: February 2015

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 19915, "Bit Selection Using Mathematically Modeled Indices Deliver Significant Improvement in Directional-Drilling Performance," by Steve Barton, SPE, Kirk Card, SPE, and David Nwachukwu, SPE, NOV ReedHycalog; Bertrand Cozon, SPE, and Cristina Marinho, Schlumberger; and Adebowale Solarin, SPE, ADDAX, originally prepared for the 2009 Offshore Technology Conference, Houston, 4-7 May. The paper has not been peer reviewed.

Despite the development of models describing fixed-cutter (FC) bit performance, selection still is made on the basis of visible geometric features. Optimal selection is complicated further by the large variation in characteristics of cutting structures, in combination with a diverse range of gauge lengths and geometries. The full-length paper presents a set of performance indices for FC bits that are derived from a sophisticated mathematical model and describe performance in terms of rate of penetration (ROP), durability, stability, and steerability.

Introduction

Offshore drilling in West Africa poses several drilling challenges that have limited drilling performance and build-rate capabilities in directional applications. The extremely soft sandstone and shale lithologies in the vertical intermediate section are prone to erosion and hole enlargement with high hydraulic energy. Hole enlargement reduces deflection forces for commercial rotary-steerable (RS) tools as well as mud motors, which significantly decreases build-rate capabilities and limits directional plans and capabilities. The associated hole enlargement in the vertical section creates a drilling environment that is subject to increased risk of lateral vibration (bit whirl), which even in soft formations is capable of catastrophic damage to bottomhole-assembly (BHA) components and the bit cutting structure.

Compromising mud flow and hydraulic energy in these soft and fast drilling sections increases risk of loading the hole with cuttings, of increased equivalent circulating density (ECD), and of stuck pipe. As depth increases, formation integrity increases, which helps to improve directional response because the increased weight on bit (WOB) provides flex to the BHA and improves control. However, in many of these applications, high hole angle, limited drilling parameters, and interbedded lithologies (with high compressive-strength variability) combine to increase risk of torsional vibration. Aside from mechanical damage to the components of the BHA, this also will lead to unpredictable directional response and reduced directional capabilities. As such, it is extremely important to select a drill bit that is matched to the specific requirements of the system, thus maximizing directional efficiency. Unfortunately, the ideal design can be difficult to identify visually.
“Is, or is not, the two great ends of Fate”: Errors in Agronomic Research
Authors: Campbell Kimberly Garland , Thompson Yvonne M. , Guy Stephen O. , McIntosh Marla , Glaz Barry
Published: February 2015

Agronomic research results include Type 1 (α) and Type 2 (β) errors. Results are often reported using α ≤ 0.05 while β is ignored. Our objective was to discuss whether a false positive was more serious than a false negative in agronomic research. For comparison, current statistical methods used in Agronomy Journal were tabulated. Most papers used null hypothesis tests with α ≤ 0.05, reporting results based on the LSD among all treatment pairs. Current practices do not account for the relative costs of false positive vs. false negative errors. A case study from the Washington State Wheat Extension trials was analyzed using mixed models with specific contrasts. While the overall effect for cultivar was significant, the β error rate for the contrast was 40% and additional replications were needed to increase the power of this contrast. A second case study analyzed trials evaluating wheat (Triticum aestivum L.) resistance to Fusarium crown rot. Optimal α and β error rates were estimated for two to eight replications with the Type1/Type2 error cost ratio set at 1:1 and 1:5. An average error rate (α and β) ≤ 0.05 could be achieved with four replications when a reduction in the β error was critical and α errors could be corrected in future experiments. Effective experimental design requires estimation of the acceptable magnitude and cost ratio of false positive and false negative errors and critical effect sizes. To be truly informative, reports of results should include this information plus observed effect sizes and variances.
Strategies for Weed Management in Organic Hops, a Perennial Crop
Authors: Delahunty Krista M. , Johnston Jason C.
Published: February 2015

To investigate the best weed management practices in small‐scale, organic northeastern U.S. hop production, we conducted an experiment that addressed the following: is straw mulch or tilling a better non‐herbicide practice to control weeds and is a cover crop effective in reducing weed populations and thus worth delaying hops planting by a year. In 2012, we established a new hopyard with about half the area planted in four varieties. We implemented three cultural approaches to weed management: straw mulch, tilling, and nothing (control). The other half of the hopyard was cover cropped in rapeseed (Brassica napus L.), and a smaller control area was left fallow. In the spring of 2013, the overwintered rapeseed was tilled in and hop rhizomes were planted where previously had been either rapeseed or fallow. We measured hop plant linear growth in both years, as well as cone mass for the 2‐yr‐old plants. To assess weed growth, we measured total weed biomass and percent cover for each weed species. We found that rapeseed did not have a positive effect on plant growth or weed suppression, and there was little evidence that waiting a year to plant hops was beneficial. Straw cover showed better measures of weed suppression, but hops wet mass in 2‐yr‐old plants was actually higher in the tilled plots. Weed management should address persistence and establishment of perennial weeds like goldenrod (Solidago spp.). The best practice may involve a mixed approach of intensive springtime tilling and weed management, followed by summer straw mulching.
Kochia Suppression with Cover Crops in Southwestern Kansas
Authors: Petrosino Justin S. , Dille J. Anita , Holman Johnathon D. , Roozeboom Kraig L.
Published: February 2015

Kochia (Kochia scoparia L.) is a well‐adapted weed found throughout the semiarid Great Plains and has increased in concern because biotypes with resistance to numerous herbicide modes of action are present, thus reducing options for control. The objectives of the research were to determine if cover crops growing during the fallow phase of a no‐till winter wheat (Triticum aestivum L.)–fallow cropping system could reduce kochia density and biomass without reducing subsequent winter wheat yields. Five fall‐sown cover crops of Austrian winter pea (Pisum sativum ssp. arvense), hairy vetch (Vicia villosa Roth.), winter triticale (Triticale hexaploide Lart.), and mixtures of Austrian winter pea‐winter triticale and hairy vetch‐winter triticale were evaluated and compared with chemical fallow and to five spring‐sown cover crops of spring lentil (Lens culinaris Medik.), spring pea (Pisum sativum L.), spring triticale, and mixtures of spring lentil‐spring triticale and spring pea‐spring triticale. Fall‐sown triticale alone or in mixture reduced kochia density by 78 to 94% and reduced kochia biomass by 98% compared with kochia in chemical fallow. Spring‐sown cover crops and kochia emerged together in early March; thus kochia density and biomass were not affected by these cover crops. Fall‐sown cover crops that produced more biomass were most effective at suppressing kochia density and biomass. All cover crops were terminated by either forage harvest or chemical application by June 1. Subsequent winter wheat yields varied by cover crop across years, and in general winter wheat after cover crops yielded comparable to or less than chemical fallow.
A Screening Protocol for Vegetative‐stage Tolerance to Phosphorus Deficiency in Upland Rice
Authors: Saito Kazuki , Vandamme Elke , Segda Zacharie , Fofana Mamadou , Ahouanton Kokou
Published: February 2015

Phosphorus deficiency is a major soil‐related constraint to upland rice (Oryza sativa L.) production in Sub‐Saharan Africa. Rice varieties adapted to low soil P and also respond well to added P fertilizer are needed. Simple and cost‐effective screening protocols could help to identify varieties with superior growth at the vegetative stage. This would be particularly useful in weed‐prone uplands where early vigor is an important trait. The objectives of this study were to (i) assess variation in aboveground biomass of 12 upland rice varieties, including the popular ‘NERICA’ varieties, with and without P supply using a double pot technique; (ii) examine if aboveground biomass measured using this technique can predict aboveground biomass at the vegetative stage under field conditions with and without P; and (iii) identify new donors for breeding for P deficiency tolerance. At 5 to 7 wk after sowing, aboveground biomass and root biomass were determined in pot and field experiments. In the pot experiment, there was significant varietal variation in aboveground biomass with and without P. Results from the pot experiment corresponded with varietal performance in the field experiments. ‘Mugdo’ generally produced the highest aboveground biomass with and without P across both experiments, followed by ‘DJ123’. Aboveground biomass without P relative to the biomass with P was consistently low in ‘Santhi Sufaid’ across both experiments. The double pot technique offers a promising, effective, and reliable approach for screening for P deficiency tolerance and Mudgo can be used as donor for improving early growth under P‐deficient soil conditions.
Identification of a New Allele at the Rsv3 Locus for Resistance to Soybean Mosaic Virus in PI 61944 Soybean Accession
Authors: Cervantes‐Martinez Innan , Chen Pengyin , Orazaly Moldir , Klepadlo Mariola
Published: February 2015

Soybean mosaic virus (SMV) is a prevalent pathogen in soybean [Glycine max, (L.) Merr.]. Several SMV resistance genes have been discovered, but most of them do not provide resistance to all strains of SMV. The objective of this research was to identify new genes or alleles displaying differential reactions to SMV strains in the SMV‐resistant soybean genotype, PI 61944. Cross combinations were made to develop F2 and F2:3 populations, followed by mapping analyses and greenhouse screenings using G1 and G7 virus strains. A resistant parent, PI 61944 (Rsv‐?), was crossed with a susceptible parent, Essex (rsv), and with differential parents, PI 96983 (Rsv1), L29 (Rsv3), V94‐5152 (Rsv4), and PI 507389 (Rsv1‐n), for allelism tests. Results indicated that resistance to SMV in PI 61944 was controlled by a single, dominant gene. This gene did not appear to be allelic to the Rsv1 locus as was previously reported. Allelism test revealed that the resistance allele in PI 61944 is located at the Rsv3 locus. A molecular marker analysis further revealed that the resistance allele in PI 61944 is located at linkage group B2 (chromosome 14). Additionally, PI 61944 exhibited unique SMV reaction patterns when compared with the reported Rsv3 allele in L29. Therefore, we propose that the new allele, Rsv3‐n, be assigned to the SMV resistance locus in PI 61944. The Rsv3 alleles are rare to find among the soybean germplasm, but can confer resistance to aggressive SMV strains; therefore, we expect PI 61944 to be useful in future breeding efforts.
Hydridothiazole Rhodium Complexes as a Result of C-H Bond Activation in Iminothiazoles Chelating Ligands
Authors: Al-hamidi Jehan , Alsaygh Abdulhamid , Al-Najjar Ibrahim
Published: February 2015

A series of 20 Schiff base ligands derived from 2-aminothiazole and its derivatives and aryl aldehydes with either [RhCl(PPh3)3] or [Rh(µ-Cl)(COD)]2 in the presence of 4 equivalents of PPh3 lead to an Rh(III) cyclometallated complex and the imine ligand (C-H) bond has been added to the metal (C-M-H). The complexes were investigated by using I.R., 1H, 13C and 31P NMR Spectroscopic techniques. The signal of the (C-H) ligand was observed as trans to the nitrogen atom in the complex which is a donor ligand.

Graphical Abstract:

Total synthesis of hydridothiazole rhodium complexes possessing rhodium hydride signal at δ (-14.60 to-15.04) ppm, trans to N-donor ligand and iminoyl carbon (7C=N) signal in Rh (III) observed at δ (220.1-237.6)ppm, lower field and suggestive of carbine like properties.
Magnetic resonance imaging as an alternative to computed tomography in select patients with traumatic brain injury: a retrospective comparison
Authors: Roguski Marie , Morel Brent , Sweeney Megan , Talan Jordan , Rideout Leslie , Riesenburger Ron I. , Madan Neel , Hwang Steven
Published: February 2015

OBJECT

Traumatic head injury (THI) is a highly prevalent condition in the United States, and concern regarding excess radiation-related cancer mortality has placed focus on limiting the use of CT in the evaluation of pediatric patients with THI. Given the success of rapid-acquisition MRI in the evaluation of ventriculoperitoneal shunt malfunction in pediatric patient populations, this study sought to evaluate the sensitivity of MRI in the setting of acute THI.

METHODS

Medical records of 574 pediatric admissions for THI to a Level 1 trauma center over a 10-year period were retrospectively reviewed to identify patients who underwent both CT and MRI examinations of the head within a 5-day period. Thirty-five patients were found, and diagnostic images were available for 30 patients. De-identified images were reviewed by a neuroradiologist for presence of any injury, intracranial hemorrhage, diffuse axonal injury (DAI), and skull fracture. Radiology reports were used to calculate interrater reliability scores. Baseline demographics and concordance analysis was performed with Stata version 13.

RESULTS

The mean age of the 30-patient cohort was 8.5 ± 6.7 years, and 63.3% were male. The mean Injury Severity Score was 13.7 ± 9.2, and the mean Glasgow Coma Scale score was 9 ± 5.7. Radiology reports noted 150 abnormal findings. CT scanning missed findings in 12 patients; the missed findings included DAI (n = 5), subarachnoid hemorrhage (n = 6), small subdural hematomas (n = 6), cerebral contusions (n = 3), and an encephalocele. The CT scan was negative in 3 patients whose subsequent MRI revealed findings. MRI missed findings in 13 patients; missed findings included skull fracture (n = 5), small subdural hematomas (n = 4), cerebral contusions (n = 3), subarachnoid hemorrhage (n = 3), and DAI (n = 1). MRI was negative in 1 patient whose preceding CT scan was read as positive for injury. Although MRI more frequently reported intracranial findings than CT scanning, there was no statistically significant difference between CT and MRI in the detection of any intracranial injury (p = 0.63), DAI (p = 0.22), or intracranial hemorrhage (p = 0.25). CT scanning tended to more frequently identify skull fractures than MRI (p = 0.06).

CONCLUSIONS

MRI may be as sensitive as CT scanning in the detection of THI, DAI, and intracranial hemorrhage, but missed skull fractures in 5 of 13 patients. MRI may be a useful alternative to CT scanning in select stable patients with mild THI who warrant neuroimaging by clinical decision rules.
Sir Victor Horsley: pioneer craniopharyngioma surgeon
Authors: Pascual José M. , Prieto Ruth , Mazzarello Paolo
Published: February 2015

Sir Victor Horsley (1857–1916) is considered to be the pioneer of pituitary surgery. He is known to have performed the first surgical operation on the pituitary gland in 1889, and in 1906 he stated that he had operated on 10 patients with pituitary tumors. He did not publish the details of these procedures nor did he provide evidence of the pathology of the pituitary lesions operated on. Four of the patients underwent surgery at the National Hospital for Neurology and Neurosurgery (Queen Square, London), and the records of those cases were recently retrieved and analyzed by members of the hospital staff. The remaining cases corresponded to private operations whose records were presumably kept in Horsley's personal notebooks, most of which have been lost.

In this paper, the authors have investigated the only scientific monograph providing a complete account of the pituitary surgeries that Horsley performed in his private practice, La Patologia Chirurgica dell'Ipofisi (Surgical Pathology of the Hypophysis), written in 1911 by Giovanni Verga, Italian assistant professor of anatomy at the University of Pavia. They have traced the life and work of this little-known physician who contributed to the preservation of Horsley's legacy in pituitary surgery. Within Verga's pituitary treatise, a full transcription of Horsley's notes is provided for 10 pituitary cases, including the patients' clinical symptoms, surgical techniques employed, intraoperative findings, and the outcome of surgery. The descriptions of the topographical and macroscopic features of two of the lesions correspond unmistakably to the features of craniopharyngiomas, one of the squamous-papillary type and one of the adamantinomatous type. The former lesion was found on necropsy after the patient's sudden death following a temporal osteoplastic craniectomy. Surgical removal of the lesion in the latter case, with the assumed nature of an adamantinomatous craniopharyngioma, was successful. According to the evidence provided in Giovanni Verga's monograph, it can be claimed that Sir Victor Horsley was not only the pioneer of pituitary gland surgery but also the pioneer of craniopharyngioma surgery.