bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Uncertain Oil Prices on Investment and Integration Efforts in the Oil and Gas Industry
Authors: El Banbi Hamdi 
Published: June 2014

Summary
A rapid review of the energy resources situation in the world today shows the important role that oil and gas play in human life. World economies will continue to rely on oil and gas as a major energy source. It is absolutely critical that policy makers - governments, investment decision makers, and oil companies - cooperate in securing a supply of energy for future generations.
The international oil industry, in its sustained efforts to optimize resources in a cost-conscious and challenging environment, has been working under several constraints: reduction in investments, environmental issues and policies, and workforce optimization. This paper highlights recommendations for facing these challenges.

Introduction
The current world energy resources emphasize the importance of oil and gas in the world energy market.Coal, beside wood, is the oldest known fossil source of energy and contributes about 27% of today's world primary energy consumption. Coal has to be cost competitive with oil and is less practical for everyday use than gas. In addition, coal is less competitive than oil and gas because of the environmental impact its extensive mining and burning. Coal's share of future total world wide energy is expected to stagnate or even drop below current levels.Hydroelectric resources account for 2.5% of worldwide energy utilization. Room could exist for some expansion, depending on investment in new hydraulic projects.Nuclear energy, which represents about 7% of the world's energy consumption, needs further technical progress to overcome serious environmental and safety concerns.Renewable resources, such as solar and wind energy, make up a fraction of 1% of the total energy consumption. These renewable resources are exotic and require further development to solve technical and practical problems before they can compete reasonably with oil and gas. While not yet available on an industrial scale, they can have an important place in unique, yet small, applications.Oil and gas are and will remain, by far, the principal sources of energy for the foreseeable future. Alone, they supply about 63% of the world's primary energy. Worldwide, gas reserves seem more geographically diverse than current oil reserves. Also, gas reserves have been developing at a faster pace during the last 2 decades. If gas reserves continue to develop at such rates, they will surpass those of oil in the not very distant future.
Advances in Cement-Plug Procedures
Authors: Heathman J.F. 
Published: June 2014

Operators set cement plugs for a variety of reasons: abandonment, sidetracking, lost-circulation control, or remedial work. However, as important as plug cementing can be to the overall success of a well program, the process often is performed without regard to wellbore conditions. The additional rig time and material costs quickly add up as multiple plugs are set. The industry average is approximately 2.4 attempts per kickoff. Studies have highlighted many of the problems encountered in plug cementing. Implementation of systematic, controlled procedures has established a near 100% success rate where used for establishing kickoff plugs.

Recommended Plug Procedure
Recent work has determined that cement plugs require the same degree of planning as primary cement jobs, plus special considerations for plug stability. A joint team of operators and a cementing service company evaluated the problems and mechanics of plug cementing. The team developed a recommended plug procedure (RPP) to alleviate problems. The procedure provides a reliable plug-setting procedure and develops a method to monitor success rates. The RPP addresses communication, temperature estimation, mud removal, slurry design, slurry volume, and plug stability. Understanding the relationships between these variables is vital to the success of spotting a balanced cement plug.

Job Design
Communication. To design a cement-plug job properly, communication among all personnel responsible for the job design is essential. It is important that personnel discuss options for each job so that assumptions are not made about equipment availability and/or capabilities. Sharing data from the field is also important. Detailed pre-/postjob data sheets have helped to build a database that has been instrumental in finding the causes of both successes and failures.
Temperature Estimation. One of the most important design variables is placement time, which is governed by pumping rates and bottomhole circulating temperatures. In most cases, little attention is paid to plug-cementing temperatures; most laboratories use published cementing schedules. At times, temperature estimates are also adjusted upward to increase the safety factor, resulting in over-retardation. The use of computer simulation or temperature surveys for temperature predictions can help ensure that the slurry will not be over-retarded. Also, a more realistic waiting on cement (WOC) time can be estimated if compressive-strength thermal-recovery schedules are slow enough to match wellbore conditions, reaching American Petroleum Inst. bottomhole static temperature only after 24 to 36 hours have elapsed.
Results From the Heidrun Field Cased-Hole Gravel Packs
Authors: Landrum W.R. , Burton R.C. , MacKinlay W.M. , Erlandsen Aasmund , Vigen Arild 
Published: June 2014

Summary
During the initial phase of the Heidrun field development, five wells were precompleted with state-of-the-art cased-hole gravel-packing techniques. The wells were tested and temporarily abandoned, awaiting tieback to the Heidrun tension-leg platform (TLP). This paper describes the completion techniques applied and presents results of an evaluation of gravel-pack efficiency for the wells. Flow and buildup tests were carried out on the semisubmersible drilling rig before and after gravel packing to evaluate initial productivity. Stabilized well-test data acquired on the Heidrun TLP at full production are presented to document ultimate completion performance for each well.

Innovations
Perforating with tubing-conveyed perforating guns on a drillstem-test (DST) string allowed perforating, perforation cleanup and flowback, pre-gravel-pack testing, and gravel prepacking to be performed in a single run. A unique loss-control-material (LCM) formula was developed and applied to control fluid losses to the formation. Prepack modeling and alternating stages of clear brine and slurry were used to optimize gravel placement. A temporary-abandonment system was developed and installed that used a weight-actuated ball valve to abandon the well temporarily without placing any damaging fluids across the production zone. Gravel-pack screen assemblies included alternative-path gravel placement with four shunt tubes per gravel-pack screen assembly.
The innovative gravel-packing techniques used at Heidrun resulted in high completion productivity and correspondingly high flow rates. A study performed to evaluate the economic impact of acceleration showed that going from a 20,000- to a 30,000-BOPD well rate added $108 million in pretax net present value to Heidrun project economics. Actual results will be greater because well rates have exceeded 43,000 BOPD.

Introduction
The Heidrun field lies 120 miles offshore mid-Norway in the Haltenbanken area in approximately 1,140 ft of water in the Norwegian Sea. Hydrocarbons were proven in three main reservoirs of Jurassic age: the Middle Jurassic Fangst group and the Lower Jurassic Tilje and Are formations. Fig. 1 provides a type log. The field is being developed from the world's first concrete-hull TLP. Ten wells were predrilled from the main 56-slot template along with six subsea, seawater injection wells drilled from the two four-slot satellite templates. First oil production occurred on Oct. 18, 1995. The Heidrun TLP is currently producing at plateau rate of more than 230,000 BOPD.
Natural Gas Transportation Issues
Authors: Adewumi Michael A. 
Published: June 2014

The Increasing Role of Natural Gas
Gas has arrived in a big way. Or has it? While it already plays a significant role in the current energy picture, all signs point to natural gas as the energy of the future. In 1995, U.S. gas demand growth outpaced that of total energy consumption by almost three to one. Predictions are that U.S. gas consumption will increase to a record 23.48 quadrillion Btu in 1996, a nearly 3% rise from 1995. It is also estimated that Canadian gas consumption will grow at twice the rate of that of the U.S. The rapidly increasing role of natural gas is motivated by its clean-burning characteristics, its relative abundance, and its wide geographical distribution. In response to this increasing demand, many large gas development projects are under way in Southeast Asia, South America, and Africa. It is therefore no wonder that several recent articles, reports, and editorials have heralded the dramatic arrival of natural gas on the energy stage.
While the current rapid rise in gas consumption is attributable to its increasing popularity in traditional usage, the impending popularization of natural gas vehicles (NGV's) should guarantee such a trend in the future. For many years, natural gas has been touted as competing with oil only as a non vehicular energy fuel. This will change. High-population states in the U.S., such as California and New York, are already converting their mass transportation systems from oil-based to gas-based. This is a growing trend in the urban areas. Europeans are also changing. In a recent, rather bold move, industry officials from 17 countries formed the European Natural Gas Vehicle Assn. The aim of this association is to globalize the use of natural gas as a vehicular fuel. With the popularization of NGV's, diverse and sustained utilization of natural gas is ensured.
Geostatistical Approaches in Reservoir Evaluation
Authors: Damsleth Eivind , Omre Henning 
Published: June 2014

Summary
Reliable characterization of the reservoir is crucial for reservoir evaluation. According to the Preface in Ref. 1, "Reservoir characterization is a process for quantitatively assigning reservoir properties, recognizing geological information and uncertainties in spatial variability." Geostatistics provides the tools to integrate the available information within a unified and consistent framework and to generate multiple realizations that can account for the uncertainty and spatial variability of the key reservoir parameters. The objective of this paper is to give our views on the use of geostatistics in reservoir evaluation, to illustrate some basic concepts and possibilities, and to increase (we hope) the reader's interest in further investigation and application of geostatistical techniques.

Introduction
Geostatistics emerged with the work of Krige in the South African mining industry in the early 1950's. The technique was introduced to the petroleum industry in the 1970's. Later methodological developments have been, to a large extent, centered around a few research groups. These include the French school, with Inst. Français du Petrole and the Ecole de Mines; the U.S. school, led by Stanford U., the U. of Texas, and the U. of Tulsa; and the Norwegian school, where the Norwegian Computing Center has played a key role. The petroleum industry has been active both in research and in demonstrating the potential of geostatistics in real case studies. In recent years, several vendors have provided suitable software, which makes the task much simpler and more efficient.

Reservoir Evaluation
The challenge of reservoir evaluation is to determine a strategy for managing the reservoir and assess the associated uncertainties. Mathematical models are used extensively for this.
Total Porosity and Bound-Fluid Measurements From an NMR Tool
Authors: Gubelin Greg , Boyd Austin 
Published: June 2014

New measurements recently available from a pulse-echonuclearmagnetic-resonance (NMR) tool enhance the usefulness of this logging technique. These include total NMR porosity and bound-fluid measurements. TotalNMR porosity provides a complete analysis of a reservoir's fluid volumes, including what is trapped in the very smallest pores associated with clays and very-fine-grained rock. This leads to improved permeability, irreducible water saturation, and effective porosity answers and, consequently, improved estimates of hydrocarbon producibility. Bound-fluid measurements, taken at logging speeds of up to 548.6 m/hr, provide irreducible water saturation and permeability when used in conjunction with another porosity device. This logging mode is favored when total NMR porosity is not required and when fast logging speeds are needed because of long log intervals, expensive rig rates, or poor wellbore conditions. Fig, 1 shows sample NMR logs taken from the Schlumberger Combinable Magnetic Resonance (CMR) tool.
NMR signal amplitude is proportional to the number of hydrogen nuclei present in pore fluids and calibrated to give porosity (free from radioactive sources)and lithology effects. However, signal decay during each measurement cycle -called the transverse relaxation time, t2 - excites more petrophysicists. Signal amplitude is the sum of all decaying t2 signals generated by hydrogennuclei measured by the tool. Separating out the distribution of t2 values by a mathematical inversion process produces a t2 distribution. Thus, permeability and bound- and free-fluid porosity can be determined.
Water in a test tube has a long t2 relaxation time of 3,500 milliseconds at25°C. However, water in rock pores has shorter relaxation times. For example, relaxation times for a sandstone typically range from 3 milliseconds for small pores to 500 milliseconds for large pores. Laboratory studies and field data show that t2 distributions in shales, shaly sands, some carbonate rocks, and heavy-oil reservoirs can have significant porosity amounts associated with t2of less than 3 milliseconds.
Oilwell/Gaswell Cement-Sheath Evaluation
Authors: Goodwin K.J. 
Published: June 2014

Technology Today Series articles provide useful summary information on both classic and emerging concepts in petroleum engineering. Purpose: To provide the general reader with a basic understanding of a significant concept, technique, or development within a specific area of technology.
All of us can readily recognize construction cement for what it is because we see it every day and it looks how it is supposed to look. Even a poor grade of construction cement is recognizable as cement to the naked eye. In our industry; cement is placed in the casing/openhole annulus for two primary purposes: to isolate producible formation horizons and to support the casing. However, we do not have the luxury of looking at the cement with the naked eye to determine its quantity and/or quality after placement. We are forced to rely on the results of measurements from a variety of electronic downhole tools to define the quality and quantity of cement placed around the casing during the primary cement placement.
The major problem associated with interpretation of the results of these measurements lies within one's definition of "good" or "bad" cement. All the cement-evaluation tools available today, as well as the service companies that design and run them, are caught in the vicious cycle of trying to define good or bad cement in the oilwell/gas well annular space. This dilemma arises because we, the operators, are asking them to tell us the compressive strength of the cement and whether the cement occupies 100% of the annular space. We cannot accept that the cement does not exhibit as high a compressive strength in the downhole measurements as it does under laboratory conditions. If the cement does not measure up, it must be bad cement and we must "squeeze" to repair it.
In truth, when we evaluate a cement in an oilwell/gas well annulus, all were ally need to know is whether cement exists in the annulus (regardless of its strength) and whether the cement occupies 100% of the annulus. We must understand that all we can do is place cement into a section of the annulus that contains neither cement nor particulate matter when we squeeze an annulus to repair a primary cement. If 10-psi cement exists in 100% of the annulus, noportion of it can be removed for replacement by a 1,000-psi cement. If the annulus is packed with settled barite (from the drilling mud) or formation particles, no portion of the particulate matter can be removed and replaced by cement. Only liquids can be removed from the annulus for replacement by squeeze cementing. Acceptance of this basic premise can both simplify evaluation of a cement sheath in a casing/openhole annulus significantly and complicate measurement methods significantly. This leaves us with trying to identify solids or liquids behind the casing, not the difference between 250- and5,000-psi cement.
Asset Optimization Concepts and Practice
Authors: Satter Abdus , Wood L.R. , Ortiz Raul 
Published: June 2014

This is paper SPE 40067. Distinguished Author Series articles are general, descriptive representations that summarize the state of the art in an area of technology by describing recent developments for readers who are not specialists in the topics discussed. Written by individuals recognized as experts in the area, these articles provide key references to more definitive work and present specific details only to illustrate the technology. Purpose: to inform the general readership of recent advances in various areas of petroleum engineering.

Introduction
The oil industry has been facing enormous business and technical challenges, including operating under a low oil-price scenario, drilling in ever-increasing water depths, and producing oil from more complex reservoir structures. Additional challenges are heavy-oil production; recovery enhancement from mature, largely depleted fields; and operating under hostile environmental conditions, in remote locations, and under uncertain regulations. In addition, tremendous competition exists for new acreage and discovered reserves in such areas as the Caspian Sea and Latin America. Fortunately, with improved resource management, integrated and innovative technologies, multidisciplinary teamwork, joint ventures, and company alliances and partnerships, the industry is in a position to develop and manage assets better than ever before. Considering the hundreds of billions of barrels of known hydrocarbons remaining to be recovered, even a small increase in recovery efficiency by the use of improved, integrated management practices can increase value significantly. This paper presents a brief review of both conventional and state-of-the-art concepts and approaches for integrated asset optimization and provides real-life examples of the practice of improved asset management.
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Prioritizing Risk-Reduction Projects
Authors: Robnett C.R. 
Published: June 2014

This paper (SPE 50937) is an edited version of SPE 46849, first presented at the 1998 SPE International Conference on Health, Safety and Environment in Oil and Gas Exploration and Production held in Caracas, 7 10 June. Original manuscript received 24 March 1998. This paper has not been peer reviewed.

Summary
Many companies find themselves struggling to address multiple recommendations from health, safety, and environment (HSE) audits; risk assessments; and incident investigations. These diverse recommendations for risk reduction compete for limited resources. Without a systematic prioritization tool, inconsistent and inefficient allocation of resources is the likely result. Risk-reduction recommendations can be prioritized on the basis of the perceived consequences of the avoided event, the risk of the event, or the risk reduction achieved by the proposal. Prioritization tools in use at Chevron have included voting systems, weighted scoring, multicriteria utility analysis, and decision analysis. This paper discusses the development of these tools and their application.
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Virtual-Intelligence Applications in Petroleum Engineering: Part 1—Artificial Neural Networks
Authors: Mohaghegh Shahab 
Published: June 2014

Distinguished Author Series articles are general, descriptive representations that summarize the state of the art in an area of technology by describing recent developments for readers who are not specialists in the topics discussed. Written by individuals recognized to be experts in the area, these articles provide key references to more definitive work and present specific details only to illustrate the technology. Purpose: to inform the general readership of recent advances in various areas of petroleum engineering.

Summary
This is the first article of a three-article series on virtual intelligence and its applications in petroleum and natural gas engineering. In addition to discussing artificial neural networks, the series covers evolutionary programming and fuzzy logic. Intelligent hybrid systems that incorporate an integration of two or more of these paradigms and their application in the oil and gas industry are also discussed in these articles. The intended audience is the petroleum professional who is not quite familiar with virtual intelligence but would like to know more about the technology and its potential. Those with a prior understanding of and experience with the technology should also find the articles useful and informative.

Background and Definitions
This section covers some historical background of the technology, provides definitions of virtual intelligence and artificial neural networks, and offers more general information on the nature and mechanism of the artificial neural network and its relation to biological neural networks.
Virtual intelligence has been referred to by different names. Among these are artificial intelligence, computational intelligence, and soft computing. There seems to be no uniformly acceptable name for this collection of analyticools among the researchers and practitioners of the technology. Of these, artificial intelligence is used the least as an umbrella term because artificial intelligence has historically referred to rule-based expert systems and today is used synonymously with expert systems. Expert systems made many promises of delivering intelligent computers and programs but did not fulfill these promises. Many believe that soft computing is the most appropriate term to use and that virtual intelligence is a subset of soft computing. While this argument has merit, we use the term virtual intelligence throughout these articles.