University Of Tulsa Research Articles

Prediction of Slug-Liquid Holdup for High-Viscosity Oils in Upward Gas/Liquid Vertical-Pipe Flow

SummarySlug-liquid holdup is a critical slug-flow parameter, which affects average liquid holdup and pressure gradient in pipes. Most experimental slug-liquid-holdup studies in the literature were conducted either by use of low-viscosity liquid for all inclination angles or high-viscosity liquid for horizontal and slightly inclined pipes, indicating a lack of experimental data for vertical flow of high-viscosity liquid. Therefore, the objective of this study is to experimentally and theoretically investigate the effect of oil viscosity on slug-liquid holdup in gas/liquid upward vertical flow, and to develop a new closure model to predict slug-liquid holdup in vertical pipes. In this study, experiments were conducted in a 50.8-mm inner-diameter (ID) vertical pipe for six oil viscosities: 586, 401, 287, 213, 162, and 127 mPa·s.A new slug-liquid-holdup closure model derived from Froude and inverse viscosity numbers was developed in this study for high-viscosity-liquid two-phase upward vertical flow. The proposed model was validated against independent experimental data and showed excellent prediction for high-viscosity data. Furthermore, the proposed model was compared with existing models that take into account the viscosity effects showing better performance. The new model was incorporated in the Tulsa University Fluid Flow Projects (TUFFP) unified model (all versions; Zhang et al. 2003b), improving the prediction of pressure gradient and average liquid holdup for high-viscosity upward vertical flow.

Artificial-Lift-System Selection Guidelines for Horizontal Gas Wells

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 181229, “Defining the Artificial-Lift-System Selection Guidelines for Horizontal Wells,” by J. Valbuena, E. Pereyra, SPE, and C. Sarica, SPE, The University of Tulsa, prepared for the 2016 SPE North American Artificial Lift Conference and Exhibition, The Woodlands, Texas, USA, 25–27 October. The paper has not been peer reviewed. Many different artificial-lift systems (ALSs) are used in horizontal gas wells. Basically, most of them were adopted and evolved from those used in oil wells. This study presents a methodology to define the most-adequate artificial-lift technique on the basis of technical limitations, a suitability coefficient (based on an attributes table), and economic analysis toward horizontal well configuration. Introduction The objective of the ALS in gas wells is to remove liquid from the wellbore, which is referred to as deliquification. The ALSs or deliquification techniques can be categorized into two groups, passive systems and active systems. Passive systems take advantage of reservoir energy. These ALSs include velocity strings, plunger lift, and foam lift. These methods are used when the gas velocity is insufficient to carry liquid naturally from the wellbore but sufficient energy remains in the reservoir to operate the method. The active systems include sucker-rod pump, progressing-cavity pump, electrical submersible pump, jet pump, and wellhead compressors. These methods add energy to the system and are generally used when the reservoir is depleted. Recommended Guidelines The development of the recommended guidelines is based on physical limitations of each ALS, well and field constraints, and a quantitative assessment of the attributes involved in the selection processes. Three main screenings are performed in the decision-making process. The first screening is based on the ALS’s limitations, including depth, flow-rate constraints, gas requirements, pressure requirements, well-integrity issues, and field conditions. The first screening rules out the unsuitable methods and leaves possible methods. The second screening is based on an attribute table that assigns a score for each attribute considered. In this screening, an average suitability factor is calculated for each feasible artificial-lift option, and the artificial-lift methods are ranked. The third screening is an economic assessment of the methods being evaluated. The net present value (NPV) and other economic parameters are calculated in this screening. Technical Limitations of Methods. Several parameters affect the ALS selection process, and they need to be considered to accomplish the main goal of the first screening, which is to rule out the unsuitable choices and provide a list of remaining methods that can be candidates for implementation. The strategy is based on defining simple rules to conduct the elimination process. These rules include limitations listed in typical-attribute tables, quick calculations, common reasoning when selecting an ALS, and typical “rules of thumb” based on experience for specific field conditions.

Technology Focus: History Matching and Forecasting (April 2017)

Technology Focus The initial work on computer techniques for assisted history matching date back to the 1960s. However, it was a long journey between the development of early methods and operational use. Initially, these methods were referred to as “automatic history matching,” giving the wrong impression that it was something we could delegate to a computer. Fortunately, industry and academia soon realized that “assisted” was a more accurate term than “automatic.” Nowadays, there is an impressive amount of literature and a large number of assisted-history-matching methods. The diversity is so vast that it is challenging to divide these methods into categories. For example, there are several flavors of methods based on sensitivity and gradient-optimization algorithms. There are also methods grounded on stochastic optimization, evolutionary algorithms, design of experiments, proxy modeling, streamline simulation, and Kalman filters. This is just to mention a few, and the list is still growing. Regardless of the specific method of your choice, I believe the main development in history matching is the recognition that it can be formulated as a Bayesian inference problem. Bayes’ rule provides an elegant framework to formalize the process of learning from data to update our beliefs. The beauty is in the fact that Bayes’ rule gave to history matching the correct meaning. History matching is no longer a searching process to find the best model. Instead, history matching is a process of mitigating uncertainty in light of new information. The papers summarized in this feature and the ones indicated in the additional-reading list are excellent examples of recent developments and applications of assisted-history-matching techniques. All are aligned with the modern Bayesian interpretation. I hope you enjoy the reading. Recommended additional reading at OnePetro: www.onepetro.org. SPE 179549 Streamline-Based Rapid History Matching of Bottomhole Pressure and Three-Phase Production Data by Dongjae Kam, Texas A&M University, et al. SPE 182684 Generation of a Proposal Distribution for Efficient MCMC Characterization of Uncertainty in Reservoir Description and Forecasting by Xin Li, The University of Tulsa, et al. SPE 182693 A Robust Iterative Ensemble-Smoother Method for Efficient History Matching and Uncertainty Quantification by Xiang Ma, ExxonMobil, et al.

Penelope Says

Penelope Says Robert Berry Crediting the Source Material At the Antwerp Symposium this summer, many readers mentioned to me that they really enjoyed the pages of PENELOPE "says" that we've been running here in the James Joyce Quarterly. Muchibus thankibus. With Dan Pipito working on new material for the website, this seemed like a good time to mention something about the origins of those pages and the way I've decided to depict Molly in them. Molly has always been the most difficult character to cast in adapting ULYSSES. I believe this is because she has such a special place in the imaginations of each true fan of the book; we all have our own Mollys. Working chronologically through the book's events as I do, I haven't had to make too many decisions about Molly just yet. There's a little in-joke to one of the images shown here in a Bloomsday poster from 2013 where I used a famous Marilyn Monroe photo as an example of the worst casting choice possible for Mrs. Marion Bloom. When the JJQ suggested we do some kind of ongoing strip in each issue with two full-color pages, "Penelope" seemed the obvious choice; subscribers here, already terribly familiar with the material, would find treats and small gags in the work that new readers of ULYSSES "seen" might find too obscure. The trick came in breaking the long speech that closes the novel into a form that might be delivered in tiny chunks of about eight pages a year. They would be more like stand-alone posters that celebrate brief moments of the text. For many reasons, this suggested to me the idea of calendar and pin-up art and I knew, right away, that Molly herself should be larger-than-life, unabashedly naked, and a kind of gigantic center of the design of each page. This is where the wonderful work of American pin-up painter Duane Bryers comes into play. Bryers's full-figured nature girl, Hilda, has become an internet favorite in the past few years. I was dimly aware of his work a few decades back and all but forgot it until researching a look for Molly on this project. A quick internet search will show you just how deeply I've mined this one artist's work to come to conclusions about where to take my own. Much of his clean lines, facial features, expressions, direct poses, lighting, and mood go into the pages you've been seeing here. His Hilda has an innocence and a naiveté that has nothing to do with our Molly, but I begin often with one woman to find the unique voice of the other. I encourage you to look for Bryers's work and see for yourself how there's a kind [End Page 413] of personality and charm there not often found in typical cheesecake art of that genre—a kind of earthy gigantism that brings my own Molly to the page. [End Page 414] Click for larger view View full resolution [End Page 415] Click for larger view View full resolution [End Page 416] Copyright © 2018 JJQ, University of Tulsa

Penelope Says

Penelope Says Robert Berry (bio) [End Page 183] [End Page 184] Robert Berry James Joyce Quarterly Robert Berry ROBERT BERRY is the Philadelphia-based cartoonist behind ULYSSES "seen," the ambitious project aimed at fully adapting Joyce's novel into a visual learning platform. His artworks have been shown in Bloomsday celebrations all over the world where they have helped to unite Joyce devotees both new and learned. He teaches at the University of Pennsylvania and occasionally gets the chance to make pretty pictures. Copyright © 2018 JJQ, University of Tulsa

Salting the Earth: The Environmental Impact of Oil and Gas Wastewater Spills.

Salting the Earth: The Environmental Impact of Oil and Gas Wastewater Spills.

Technology Focus: Gas Production Technology

Technology Focus What do you do when the power goes out? That situation might evoke the tranquility of putting down your smartphone and looking out the window for a few moments of quiet reflection. Or it might bring the anxiety of wondering if your indoor plumbing will freeze when the power fails on a cold, dark night. But what if it brought the panic of being in the middle of a difficult childbirth operation in a remote hospital that has access only to unreliable electricity generated by intermittent sources? That is the painful reality outlined in The Moral Case for Fossil Fuels, a new book written by Alex Epstein. With a background in philosophy, Epstein wonders why we all seem to accept that the world is “addicted” to our “bad” product while that same product provides us with a standard of living only available to royalty a century ago. With an unbiased perspective, he notes that increased fossil fuel use correlates strongly with increased standard of living, wealth, life expectancy, and food availability and decreased deaths from severe weather events. Why are we so negative about something that has done so much good for so many people? Anthropogenic-global-warming activists argue that returning the climate to prehuman conditions is their ultimate goal, even if decreasing human wellbeing is required. They conveniently forget that the climate was changing before humans arrived, the climate will continue to change after we are gone, and that we have never been successful in attempts to “unchange” the climate. They endorse naive energy alternatives at impractical prices or that are only found in science fiction. To their credit, science fiction does eventually come to pass sometimes; but, do we power hospital equipment with wishful thinking until then? The US Energy Information Administration predicts that, from 2012 to 2020, subsidized intermittent wind and solar energy will nearly double from 3.9 to 6.5% of total world energy consumption. Meanwhile, natural gas provides reliable heating, cooling, and electricity at free-market prices for billions of people. Each year, gas-fired power plants allow millions of additional people to gain their first access to dependable electricity for lighting, smoke-free cooking, and, yes, 21st-century health care. On the basis of long-term fuel-use trends, we can expect that, within a couple of centuries, the sun may provide the same large-scale, low-cost, and reliable power now provided by natural gas. Until then, I will take that rare opportunity when my office loses power to remember to be grateful for the standard of living that fossil fuels have provided for me and billions of other lucky people around the globe. JPT Recommended additional reading at OnePetro: www.onepetro.org. SPE 174852 Liquid Loading of Highly Deviated Gas Wells, From 60 to 88° by Y. Alsaadi, University of Tulsa, et al. SPE 177567 Integrated Methodology for Production and Facilities Analysis To Optimize Barnett Shale Gas Production— A Case Study by A.A. Moniem Ahmed, Schlumberger, et al. SPE 179537 Experimental Study on Revaporization Mechanism of Huff ’n’ Puff Gas Injection To Enhance Condensate Recovery in Shale Gas/Condensate Reservoirs by Xingbang Meng, Texas Tech University, et al. SPE 180247 Infill-Drilling Opportunity in Fruitland Coal, San Juan Basin, Colorado by Prannay Parihar, Chevron, et al.

Accusing student fails to get vindication

Case name: Ross v. University of Tulsa, No. 14‐CV‐484 (N.D. Okla. 04/15/16).

Developments for the application of the Wire-Mesh Sensor in industries

Wire-Mesh Sensors (WMS) are applied in many research applications to determine the distribution of the phase fraction and to visualize the flow behavior within a pipe. However, their application in industries is restricted due to the procedure of data acquisition and offline post processing. Here a new design of Wire-Mesh Sensor for monitoring void fraction and flow pattern behavior is presented. As result of online data evaluation cross-sectional void fraction information is provided in almost real-time. Additionally, the present flow pattern is determined by statistical analysis of recorded data of a time period of 10s. This is the first time a Wire-Mesh Sensor was used for this purpose. With the help of fuzzy methodology a distinction of the four main flow patterns of vertical upward gas-liquid flow is possible. Furthermore, transition regions can be identified. The algorithm is based on the evaluation of statistical void fraction distribution as result of Wire-Mesh Sensor data. Validation experiments of the new adopted algorithms are carried out in a 50mm-ID two-phase air-water flow-loop at Tulsa University Horizontal Well and Artificial Lift Projects (TUHWALP).

Experimental Investigation of Three-Phase Low-Liquid-Loading Flow

Summary An experimental study is conducted by use of a 6-in.-inner-diameter (ID) facility to investigate characteristics of three-phase stratified wavy flow in horizontal pipelines. The experiments are conducted under low-liquid-loading condition, which is very commonly observed in wet-gas pipelines. The analyzed flow characteristics include wave pattern, liquid holdup, water holdup, pressure gradient, and wetted-wall fraction. The experimental range covers superficial-gas-velocity (vSg) values of 8 to 23 m/s, superficial-liquid-velocity (vSL) values of 1 to 2 cm/s, and inlet-liquid-stream water-cut values of 0 to 100%. Differential-pressure transmitters, a quick-closing valve and pigging system, and a high-speed camera are used to acquire the data. The trends of the data with respect to input parameters are investigated. The performances of commonly used models are compared with liquid-holdup, pressure-gradient, and water-holdup experimental results. The observed wave patterns include stratified smooth and stratified wavy with 2D waves, 3D waves, roll waves, and atomization flow. The transitions between the flow patterns vary as a function of water cut. The trends of pressure gradient, liquid holdup, and water holdup with respect to vSg, vSL, and water cut are observed, and interpretations on the basis of physics are provided. The predictions of a transient multiphase-simulation software; the Tulsa University Fluid Flow Projects (TUFFP) unified model (Zhang et al. 2003), version 2012; Beggs and Brill (1973); Taitel and Dukler (1976); and Xiao et al. (1990) are compared with the acquired experimental data. The results from the transient multiphase-simulation software, Taitel and Dukler (1976), and Xiao et al. (1990) are in good agreement with experimental liquid-holdup and pressure-gradient data, but the three-phase water-holdup trends are not predicted well. The complicated nature of liquid/liquid interactions in three-phase low-liquid-loading flow causes greater uncertainties in predictions. The number of experimental three-phase data, especially with larger pipe diameters, is very limited. This paper provides comprehensive data for three-phase stratified flow for a 6-in.-ID pipe. In addition, the prediction performance of the commonly used predictive tools in the industry is provided.

A Data-Driven Model for History Matching and Prediction

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 173213, “INSIM: A Data-Driven Model for History Matching and Prediction for Waterflooding Monitoring and Management With a Field Application,” by Hui Zhao, SPE, Yangtze University; Zhijiang Kang, China Petroleum and Chemical Corporation; Xiansong Zhang, China National Offshore Oil Corporation; Haitao Sun and Lin Cao, Yangtze University; and Albert C. Reynolds, The University of Tulsa, prepared for the 2015 SPE Reservoir Simulation Symposium, The Woodlands, Texas, USA, 23–25 February. The paper has not been peer reviewed. In this paper, the authors derive and implement an interwell numerical simulation model (INSIM) that can be used as a calculation tool to approximate the performance of a reservoir under waterflooding. In INSIM, the reservoir is characterized as a coarse model consisting of a number of interwell control units, and each unit has two specific parameters: transmissibility and control pore volume. INSIM is applied to perform history matching for parameter estimation and to infer interwell connectivity and geological characteristics. Introduction History matching with a reservoir simulator is the most common way to condition rock-property fields to production data. However, production data are never sufficient to resolve the reservoir properties (e.g., gridblock permeabilities), and few assisted-history- matching tools exist in commercial reservoir simulators. Consequently, when a reservoir simulator is used as the forward model when history matching, the number of reservoir parameters is often reduced to a small number on the basis of computational experiments and physical insight. Although the INSIM methodology introduced here does limit the number of history- matching parameters, the primary objective of INSIM is to provide a fast, simplified simulation model to calculate flow and transport sufficiently well that, when INSIM is used for history matching, the resulting history-matched model can be entered into INSIM to provide reasonable future predictions and provide information on the flow dynamics of the reservoir. It is hoped that the model and methodology presented here will prove useful for monitoring and understanding waterflooding operations conducted on a black-oil reservoir and that INSIM will ultimately be useful for waterflooding optimization. Models based on the statistical correlation or the connectivity between injectors and producers estimated from flow-rate data have been used previously to characterize reservoirs for the purpose of waterflooding management. Unlike previous correlation-based models, INSIM is able to effectively predict the water cut and oil-production rate and hence can be used as the forward model for assisted history matching of these data. Specifically, the model can be used in automatic history matching. Moreover, the model is derived directly from the correct two-phase-flow mass- balance equations, and thus the transmissibilities derived from history matching reflect an average transmissibility between wells. In addition, because INSIM is based on simulation flow equations, it can incorporate large changes in flow rates, flow directions, and injector allocation factors—the interaction between pairs of producers and the conversion of producers to injectors. At the same time, INSIM retains the computational efficiency of previous correlation-based models that incur far less computational cost than a traditional numerical reservoir simulator.

The Sixth Conference on the Biology of Plethodontid Salamanders: University of Tulsa, 2014

The Sixth Conference on the Biology of Plethodontid Salamanders: University of Tulsa, 2014

Rapid Quantification of Juniperus Pollen Proves Overlapping Pollen Seasons

Rashmi Prava Mohanty, Mark A. Buchheim, PhD, Estelle Levetin, PhD, FAAAAI; University of Tulsa, Tulsa, OK, University of Tulsa. RATIONALE: Microscopic analysis of air samples fails to determine the pollination season overlap between various species with morphologically similar pollen such as members of the Cupressaceae and Poaceae. Previously, we showed it was possible to use PCR to identify Juniperus ashei pollen from air samples. The present study was undertaken to determine if qPCR could be used to determine airborne pollen counts for three Juniperus species and define the pollination season overlap. METHODS: The atmosphere in Tulsa, OK(USA) was monitored with a Burkard sampler and analyzed by microscopy using standard methods. A second Burkard sampler was used from 2013 to 2015 for molecular analysis; 109 samples were tested with species-specific primers and probes designed for J.ashei, J.pinchotii and J.virginiana. Numbers of pollen grains obtained from microscopy were compared with numbers obtained from qPCR by Spearman correlation coefficient. RESULTS: Cupressaceae pollen was detected in the Tulsa atmosphere from October through April. The qPCR counts for total Juniperus pollen showed a significant correlation with the microscope counts, R50.92, p<0.001. Quantitative PCR data showed overlapping pollen seasons. In the fall, data indicated five days (in two years) with both J.pinchotii and J.ashei pollen. Similarly, in January and February eight days (in two years) indicated both J.ashei and J.virginiana pollen in the air. CONCLUSIONS: This approach is a rapidmethod to identify and quantify specific pollen types and the pollen season overlap where species and genera cannot be distinguished by microscopy. Defining the exact pollination season will be a benefit for patients sensitive to pollen from specific taxa.

Penelope Says

Penelope Says Robert Berry (bio) and Dan Pipito [End Page 159] [End Page 160] Robert Berry ROBERT BERRY is the Philadelphia-based cartoonist behind ULYSSES "seen," the ambitious project aimed at fully adapting Joyce's novel into a visual learning platform. His artworks have been shown in Bloomsday celebrations all over the world where they have helped to unite Joyce devotees both new and learned. He teaches at the University of Pennsylvania and occasionally gets the chance to make pretty pictures. Copyright © 2018 JJQ, University of Tulsa

Prediction of Critical Gas Velocity of Liquid Unloading for Entire Well Deviation

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 17846, “Prediction of Critical Gas Velocity of Liquid Unloading for Entire Well Deviation,” by J. Li, Trican Well Service, and F. Almudairis and H. Zhang, The University of Tulsa, prepared for the 2014 International Petroleum Technology Conference, Kuala Lumpur, 10–12 December. The paper has not been peer reviewed. Liquid loading is a common production problem in mature gas wells. Correct prediction of the critical gas velocity at which the well starts to load is very important to the operators because it may allow them to take appropriate measures to prevent liquid loading and extend well production life. In this paper, a database related to the critical gas velocity is compiled with data from published literature. A new model is developed and evaluated with the experimental data. Introduction Gas wells often produce water and other condensate. In the early production stage, the gas-flow rate is high enough to carry the produced liquids to the surface. As the reservoir pressure is depleted, the produced-gas-flow rate decreases until the gas reaches a critical condition, at which time liquid loading is initiated. At the inception of liquid loading, the gas-flow rate is not sufficient to carry the liquid completely to the surface and the liquids start to accumulate at the bottom of the well. A backpressure then builds up, and the increased reservoir pressure will eventually be sufficient to lift the liquid to the surface. Once the liquid slug is pushed out by the gas, the liquid starts to reload the well again and the cycles are repeated until the well is eventually loaded completely and gas production stops. The most common liquid-loading symptoms observed in the field are pressure (or pressure-gradient) fluctuations and reduction of gas production. In general, there are two different liquid-loading principles proposed in the literature: liquid-droplet fallback and liquid-film reversal. The complete paper contains a literature review that follows the development of these principles. Data Compilation Liquid-loading-initiation mechanisms have been investigated in 3-in.-innerdiameter pipes with deviations of 0, 15, 30, and 45° from vertical. Others have used the same flow loop to study the liquid loading at deviations of 60, 70, 80, 85, and 88° from vertical. The superficial gas velocity ranged between 2 and 40 m/s, and the superficial liquid velocity varied from 0.01 to 0.1 m/s. Approximately 450 tests were performed. Pressure gradient, liquid holdup, and liquid-film thickness at the bottom of the tubing were also measured. Highspeed video cameras were used to observe flow pattern and film reversal. Complete film-reversal transition was applied to determine the critical gas velocity for the liquid-loading initiation. In the vertical case, the liquid film around the pipe periphery is almost uniform, and in the deviated case, it is nonuniform. In the latter, there is more liquid accumulated at the bottom of the pipe than at the top. This difference in liquid-film distribution around the pipe yields a difference in flow-pattern transitions and film reversal.

Teaching Trans for Children, Youth, and Adults Who Care for Them

Teaching Trans for Children, Youth, and Adults Who Care for Them

A Museum Anthropologist in Academic Practice

M personal and professional journey as a museum anthropologist has spanned more than 35 years and provided me with opportunities to serve as a curator, division head, museum director, and university professor. My early career included appointments in curatorial positions in a range of museum settings including the Oklahoma State Historical Society, the Oklahoma State Museum of History, the White Hair Memorial, a cultural center for the Osage Indian community, and the Science Museum of Minnesota. In these capacities, I contributed to the stewardship of collections and the development of interpretive exhibitions, programs, and publications. In each case, the focus was museum practice with limited incentive or encouragement to engage in research and publication activity that was not directly related to museum matters. A decade into my career, I received an invitation to teach undergraduate students as an adjunct professor at Macalester College and Hamline University. This was my first experience in applying my practical experiences to college level instruction in museum anthropology. Fifteen years into my career, I ventured into museum management, accepting an appointment as Senior Curator at the Gilcrease Museum, a municipal museum of history and art in Tulsa, Oklahoma. Over the next decade, I discovered that I not only enjoyed administration but also valued the opportunity to engage in long-term programmatic and institutional development. As the scope and scale of my responsibilities changed over time, I engaged in some limited teaching as an adjunct professor at the University of Tulsa and struggled to sustain a research and publication program in Native American ethnology and ethnohistory. My professional transition is from museum to academy. In 2003, I accepted a position at the University of Memphis as Associate Professor of Anthropology and Director of the C. H. Nash Museum of Anthropology and Chucalissa Archaeological Park. Just as my management and administrative responsibilities increased, A MUSEUM ANTHROPOLOGIST IN ACADEMIC PRACTICE

Refined reconstruction of liquid–gas interface structures for stratified two-phase flow using wire-mesh sensor

Wire-mesh sensors (WMS), developed at HZDR [13,4], are widely used to visualize two-phase flows and measure flow parameters, such as phase fraction distributions or gas phase velocities quantitatively and with a very high temporal resolution. They have been extensively applied to a wide range of two-phase gas–liquid flow problems with conducting and non-conducting liquids. However, for very low liquid loadings, the state of the art data analysis algorithms for WMS data suffer from the comparably low spatial resolution of measurements and from boundary effects, caused by e.g. flange rings – especially in the case of capacitance type WMS. In the recent past, diverse studies have been performed on two-phase liquid–gas stratified flow with low liquid loading conditions in horizontal pipes at the University of Tulsa. These tests cover oil–air flow in a 6-inch ID pipe and water–air flow in a 3-inch ID pipe employing dual WMS with 32×32 and 16×16 wires, respectively. For oil–air flow experiments, the superficial liquid and gas velocities vary between 9.2m/s≤νSG≤15m/s and 0.01m/s≤νSL≤0.02m/s, respectively [2]. In water–air experiments, the superficial liquid and gas velocities vary between 9.1m/s≤νSG≤33.5m/s and 0.03m/s≤νSL≤0.2m/s, respectively [17,18]. In order to understand the stratified wavy structure of the flow, the reconstruction of the liquid–gas interface is essential. Due to the relatively low spatial resolution in the WMS measurements of approximately 5mm, the liquid–gas interface recognition has always an unknown uncertainty level. In this work, a novel algorithm for refined liquid–gas interface reconstruction is introduced for flow conditions where entrainment is negligible.

E&amp;P Notes (May 2015)

E&amp;P Notes Lessons From the Aviation Industry on Automation Trent Jacobs, JPT Senior Technology Writer One of the defining features of the 21st century will undoubtedly be the changing relationship between humans and automated machines. The aviation industry has long been a champion of automation and in March, three experts from this field offered their insights to oil and gas professionals about how the technology continues to be qualified and adopted. The presentations were made in London at the SPE’s Drilling Systems Automation Technical Section (DSATS) and IADC Advanced Rig Technology symposium, which is held each year on the eve of the SPE/IADC Drilling Conference and Exhibition. Faster Recognition Stephen Rassenfoss, JPT Emerging Technology Senior Editor A project to predict how much carbon dioxide injected into an oil field is likely to remain there forever set off the US Department of Energy (DOE) on a search for faster data analysis methods. Speed matters because making projections going out as far as 1,000 years using a probabilistic model (Monte Carlo) will require long computing times, which are costly. DOE is trying to limit the total time by seeking quicker, lower-cost ways to generate the required data inputs by finding reasonably accurate methods that are faster than multiple processing runs of a full-field reservoir simulation model. Tough Tracers Stephen Rassenfoss, JPT Emerging Technology Senior Editor A new miniature pressure/temperature sensor comes packaged inside a tough small ball capable of traveling to the bottom of a well while drilling and returning with data on board. The outer shell of the ball allows electrical components printed on a circuit board to survive a trip in the drilling mud to the bottom of the well, survive a close encounter with the drill bit, and return with readings along the way that can be wirelessly downloaded. Creators of the balls are seeking a lower-cost alternative to logging tools located behind the drill bit. The tracer was created by a company started by Mengjiao Yu, an assistant professor of petroleum engineering at the University of Tulsa, with backing from Saudi Aramco. Corrosion Prediction Stephen Rassenfoss, JPT Emerging Technology Senior Editor There are oil fields in Saudi Arabia with many, long-lived wells and not enough inspection equipment to frequently check all the pipes for corrosion damage. “With a limited number of corrosion logging tools, we cannot cover all of them in 1 or 2 years,” said Mohammed AlAjmi, a production engineer for Saudi Aramco, who estimated that it would take 5 years with the available equipment in a presentation at the SPE Digital Energy Conference and Exhibition in The Woodlands, Texas. To reduce the risk of undetected corrosion damage inside and outside the casing, AlAjmi developed a method to predict which wells were at the highest risk of damage using data-driven models and artificial intelligence methods.

Technology Focus: Deepwater Projects (May 2015)

Technology Focus As the oil and gas industry pushes into deeper water, more-complex environments, and frontier unproduced areas, the technical and nontechnical risks related to appraisal and development of deepwater projects are likely to continue to increase substantially. While the technical challenges related to deepwater developments are significant— perhaps more significant and critical to the venture success—it is important that the nontechnical aspects of managing a new development in a frontier area be incorporated at the onset. After the successful discoveries in deepwater basins across the globe in west Africa, the North Sea, the Gulf of Mexico, Brazil, and elsewhere, operators are using the lessons learned and technologies developed in these fields to explore other frontier deepwater fields. The exploration in deep water becomes complex on the basis of various factors, such as water depth, geological formations, weather conditions, lack of oilfield infrastructure, and material and tools availability. The definition of deep water may vary with operators, but one definition of a deepwater field is any area of exploration where the water depth is greater than 150 m and there is a subsea blowout preventer. NORSOK defines deep water as water depth in excess of 600 m. Deep water may range from 600 to 3000 m, and ultradeep water is anything deeper than that. Deepwater operations create several additional challenges that need to be addressed in the design phase. Some of these, such as low temperatures at seabed, shallow flow hazards, and possible hydrates, are problems that are most commonly associated with deepwater operations. Other challenges, such as low fracture gradients and proper mud removal for cement placement and zonal isolation, are also common in nondeepwater environments; however, these become more complex, more significant, and more difficult to manage in deep water. There is no question that deepwater production will play a very important part in meeting the world’s future energy demand. The challenge for the oil and gas industry is to meet this demand safely, efficiently, and profitably. This is not an easy challenge in deep water, given the limited margin for error. The technical complexity and multibillion-dollar development costs require a robust development strategy that allows a project to deliver the promised value within the constraints of time. JPT Recommended additional reading at OnePetro: www.onepetro.org. OTC 25135 Deepwater Development Strategy by Martijn Dekker, Shell, et al. OTC 25443 50 Reservoirs, 48 Well Slots, and Two TLPs—Maximizing Recovery From the Deepwater Prolific Mars Field by Derek Newberry, Shell SPE 169245 Overcoming Ultradeepwater Cementing Challenges.in.the Caribbean by N. Gupta,_Schlumberger, et al. SPE 170286 A Novel Approach in Locating Single Loss Zone During Deepwater Drilling With Distributed- Temperature Measurement by Yuanhang Chen, The University of Tulsa, et al.