bluuebunny/crossref_metadata_2025 huggingface dataset:
Techbits: China Workshop Examines Fractured Carbonate Reservoirs
Authors: JPT staff _
Published: February 2015

Techbits

An SPE Applied Technology Workshop (ATW) on “The Characterization of Effective and Efficient Development of Fractured Carbonate Reservoirs” was held 15-18 June 2014 in Nanjing, China. Participants reviewed recent advances in exploration and production and the technical challenges presented by these reservoirs.

A variety of carbonate reservoirs exist worldwide, mainly paleokarst reservoirs. Because of various scales, poor continuity, strong heterogeneity, accumulation in vugs and fractures, and complex flow behaviors, the efficient development of fractured carbonate reservoirs is quite challenging.

Li Yang, cochairperson of the workshop, opened the session and ATW Chairman Wang Zhigang delivered one of two keynote speeches. He focused on the challenges and current activities of a key carbonate reservoir, Tahe, that he said represented the theme of the ATW. Usman Ahmed, also a workshop cochairperson, introduced the second keynote speaker, Christine Ehlig-Economides. She recalled an ATW a decade ago that also had focused on the Tahe reservoir. She set the stage for a discussion on how much the industry has advanced and the challenges that lie ahead.

In his keynote speech, Wang of Sinopec described the technical challenges and techniques used at Sinopec’s Tahe oil field in western China. The Tarim basin is the company’s largest carbonate play, with proven reserves of 1.3 billion tons and depths of 5300 m to 6300 m. The oil and gas accumulated in pores, vugs, and fractures of severe heterogeneity and depth make it difficult to predict and describe reservoir characteristics, he said.

Carbonate reservoir characterization and evaluation techniques have been developed that have improved the predictability of the carbonate reservoir and its distribution and have increased drilling success, he said. In the Ordovician carbonate reservoir of Tahe, a series of techniques such as paleokarst landform categorization, paleokarst cycle division, hydrocarbon accumulation period analysis, logging for reservoir identification, and evaluation have been implemented. In addition, massive acid fracturing (high pumping pressure, high injection rate, large scale) has become a major technique for development at the field.

In sum, the technical challenges are:

Ultradeep, highly heterogeneous reservoirs with low-resolution seismic data make it difficult for reservoir prediction.

The form of fractures and vugs and oil and gas accumulation in such reservoirs make reservoir modeling difficult.

A variety of reservoir fluid systems exist, which lead to a complex oil-water distribution. Current simulation techniques need to be further improved.

Severe channeling and breakthrough were detected after waterflooding was applied. Further research is needed to improve waterflooding, residual oil characterization, and water-control techniques.

Drilling activities are extremely challenging and costly. Drilling technology needs to be further developed or modified.
As Scarcity Hits, Water Tech Flows In
Authors: Jacobs Trent
Published: February 2015

Water Treatment

Although the oil and gas boom in the United States owes much of its success to the abundance of cheap sources of fresh water, the status quo is beginning to change. Groundwater remains the main source of water for most onshore exploration and production companies; however, they are increasingly investing in produced and flowback water- treatment technologies. Many of the same companies are also turning to brackish water sources in places where freshwater aquifers are becoming depleted, such as the Permian Basin that spans west Texas and eastern New Mexico. Brackish water, sometimes called fossil water, has less salt content than seawater, making it cheaper to treat, and is typically found in the same areas where hydrocarbons are developed.

The Fasken Oil and Ranch in Midland, Texas, relies on produced-water recycling and brackish water for nearly all of its oil and gas operations at its primary operating area. In August, a larger operator in the area called to buy produced water from Fasken, said Jimmy Davis, operations manager at the family-owned oil company.

The friendly request exemplifies the increasingly desperate water situation that oil companies are facing in the Permian Basin, one of the most productive onshore areas in North America. “They are in a fix for water,” Davis said. “I am starting to hear that over and over. What we are doing out here as an industry is using water to frac, and we are in a drought-stricken area so you have to find other means than fresh water to meet those needs.”

Based on the number of inquiries and activity that he is seeing from neighboring companies, Davis said he predicts that over the next few years, a majority of Permian Basin operators will turn to brackish and produced water as their primary sources. “If you are going to continue to frac like we are, that is what you are going to have to do to sustain it,” he said.

According to a market analysis report by Houston-based PacWest Consulting, onshore oil and gas companies in the United States spent USD 20.1 billion last year on water-management services. While only 4% of the spending was for water treatment, if projections hold true, then this year will mark the turning point. The report said that water treatment represents the smallest yet fastest growing segment of the water-management market with a forecast of 23% growth each year to USD 1.3 billion by 2016. “Prevailing drought conditions and long-term sustainability of freshwater sources is expected to steadily increase demand for treatment services,” the report concluded.
University R&D Around the World: Part 2
Authors: Betz Jack
Published: February 2015

R&D on Campus

As the task of finding and producing hydrocarbons becomes more difficult, complex, and costly, the number of universities focusing on finding solutions has risen. Whether the frontier is heavy oil, deep water, or remote locations, efforts within academia are under way to solve the next generation of technical challenges confronting hydrocarbon E&P operations. Because many noteworthy research and development (R&D) efforts exist at universities all over the world, the intent of this article is not to cover all of them but to present a sampling from many geographical locations. Part 1 of this two-part series appeared in September’s JPT.

The University of Tulsa (TU) was formed in Tulsa, Oklahoma, in 1907, when the boards of Kendall College and McFarlin College made the decision to merge the two institutions. TU has offered academic degrees in petroleum engineering since 1932 and has a research and development (R&D) program dating back to 1965, when property and buildings were donated by Humble Oil and Refining Company, creating TU’s north campus, which is devoted entirely to oil and gas.

TUDRP

To support its research, the university formed the Tulsa University Drilling Research Program (TUDRP) consortium, which currently has 18 industry partners. TUDRP aims to improve drilling operations while reducing costs and the number of safety and environmental incidents.

According to principal investigator and director of TUDRP, Stefan Miska, the center has completed 153 research projects since 1968; TUDRP’s 2014–15 programming brochure lists 13 active research projects.

The center is operated by 27 personnel—including senior-level researchers, nonresearch employees, and 16 advanced-degree candidates who assist in conducting the studies.
Combining Pressurized-Mud-Cap-Drilling and Early-Kick-Detection Techniques
Authors: Wilson Adam
Published: February 2015

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 165893, ’Combining Pressurized-Mud-Cap-Drilling and Early-Kick- Detection Techniques for Fractured Formations Overlying a High-Pressure Reservoir in Offshore Kalimantan,’ by Benny Benny, SPE, Andri M. Hidayat, Ardia Karnugroho, SPE, Julius Sosa, and Julmar Shaun S. Toralde, SPE, Weatherford, prepared for the 2013 SPE Asia Pacific Oil and Gas Conference and Exhibition, Jakarta, 22-24 October. The paper has not been peer reviewed.

Pressurized-mud-cap drilling (PMCD) and early kick detection (EKD) are two unconventional drilling techniques that have been used widely individually, mostly in relation to closed and pressurizable systems and to managed-pressure-drilling (MPD) applications. The techniques, however, are seldom used together as an integrated setup. This paper describes a synergized PMCD and EKD setup and the field deployment where it was used to drill a well successfully offshore Kalimantan, Indonesia, that had a high-pressure formation below a zone prone to severe circulation losses.

Introduction

Many drilling problems offshore Kalimantan involve lost-circulation problems and unintended influxes. Drilling conventionally through fractured and extremely vugular carbonate formations, which are prone to severe lost-circulation problems, can lead eventually to well-control situations. Aside from that, significant time and resources are required to cure the losses before conventional drilling can be continued. In addition, of 1,000 ft of carbonate formation drilled offshore Kalimantan, the fractures often are present in layers, which will multiply considerably the time and resources spent each time severe or total loss is encountered. One of the more well-known ways to mitigate this problem is implementation of the variant of MPD called PMCD, which enables the operator to drill through the fractured formation safely and efficiently.

Meanwhile, also in offshore Kalimantan, most of the zone that resides just several feet below the fractured carbonate formation is highly pressurized gas reservoir. Drilling conventionally through such a pressurized zone exposes the operation to greater risk because of a lack of precision in detecting any influx or outflux during the drilling operation. A better method for detecting influx is the use of a flowmeter to monitor the flow from the well. The most common flowmeter used is a Coriolis mass flowmeter (CMF). Although the CMF has the advantage of great precision in measuring flow rates, the conventional setup lacks accuracy because the system is open to the atmosphere. A further improvement is to use it in conjunction with the MPD system to create a closed-loop system that will increase accuracy. This is the EKD system.
Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids
Authors: Carpenter Chris
Published: February 2015

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 169479, ’Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids From Tight/Shale Reservoirs,’ by G.J. Moridis, SPE, Lawrence Berkeley National Laboratory, and T.A. Blasingame, SPE, Texas A&M University, prepared for the 2014 SPE Latin American and Caribbean Petroleum Engineering Conference, Maracaibo, Venezuela, 21-23 May. The paper has not been peer reviewed.

Production of low-viscosity liquids, including condensates, from tight reservoirs such as shales is severely restricted by the ultralow permeability of such formations, limiting production to a very small fraction, usually less than 5%, of the liquids in place. In this study, the authors evaluate, by means of numerical simulation, several possible strategies to enhance low-viscosity- liquid production from such reservoirs. The objectives of this effort are to remove from further consideration strategies that hold limited promise, and to identify strategies that have potential for further study.

Introduction

The remarkable success of gas production from tight reservoirs and shale reservoirs has not been matched by similar progress in the production of relatively- low-viscosity liquid hydrocarbons (including condensates) because of the significant challenges to liquid flow posed by the ultralow permeability of such reservoirs.

Increasing the recovery of liquids from these ultralow-permeability systems even by 50% over its current very low levels not only will increase production and earnings but will have considerable wider economic implications because the increased recovery will affect reserves and the valuation of companies. The authors’ effort aims to address this issue by using numerical simulation to investigate a wide range of possible strategies for improved liquid production from tight/shale reservoirs. In essence, this is an attempt to provide a baseline mechanistic study that deploys some state-of-the-art tools in reservoir modeling. The paper focuses on determining the baseline performance of various key production methods that are considered standard in the attempt to produce low-viscosity liquids from tight reservoirs and shale-oil reservoirs. These include recovery by use of displacement methods, viscosity-reduction methods, enhanced reservoir stimulation, and combinations thereof.

For a discussion of the simulation code and the underlying fundamental equations of flow and transport, please see the complete paper.

Fractured-System Description and Subdomain Representation

Subdomains. The fractured system in producing tight gas reservoirs and shale-gas reservoirs can be described as a set of interacting subdomains.
Energy 360: Cutting Rocks - With A Huge Sense of Purpose
Authors: Haldorsen Helge Hove
Published: February 2015

President's column

The Yin and the Yang of E&P - No Shadow without Light

What does a sense of purpose have to do with anything, you may ask? The exploration and production (E&P) business is about rocks, rigs, and remotely operated vehicles (ROVs). It is about compound average growth rates (CAGR), return on average capital employed (ROACE) and great health, safety, security, environment, and social responsibility (HSSE-SR) performance. It is not about soft stuff such as a sense of purpose, passion, and creativity, or is it? I am going to try to convince you that it is. The two are the yin and the yang of E&P or the hard and the soft side of E&P. After 36 years in the industry, I have come to realize that the hard side of E&P actually is soft, since delivery depends 100% on the human element and that the soft side is the hardest to get right. The truth is you cannot have one without the other (Fig. 1). If a sense of purpose and passion are two key components of light, then strong growth and a healthy return on investment are the resulting shadows. You cannot have the shadows without the light.

The Giza Pyramids, 1500 BC

If we asked a craftsman cutting rocks next to one of the three ancient Giza pyramids being built around 1500 BC, “Excuse me, sir, are you cutting rocks?” His answer would have been, “No, I am not just cutting rocks, I am building a pyramid.” The difference is the sense of purpose associated with what he was doing. He was involved with something greater than himself and his own self-interest that inspired and energized him in his work. With a sense of purpose, suddenly, what you do for a living is not just a job. It is much more than that. It is about making a difference. It is about changing the world.

240,000 New Energy Customers Every Day

Today, we have 7.2 billion people on the planet. Every hour, the Earth’s population grows by some 10,000 new energy customers and by a quarter million every day. After just a week, we have generated a new city with a population of 1.5 million with every new citizen wanting one thing in particular: energy. This is because our new world citizens want the same as us: electricity at home, heating and cooling, mobility, and transportation. (Note: Approximately 1.3 billion people are still without electricity and, according to the World Bank, only 24% of Africans have access to electricity.
Visualizing Low-Salinity Waterflooding
Authors: Sanderson Colin , Sohrabi Mehran
Published: February 2015

Technology Update

Low-salinity waterflooding has recently attracted considerable interest from governments, researchers, and oil companies, who are evaluating the method’s potential to increase oil recovery. While laboratory work and field tests have indicated that low-salinity waterflooding can have positive results, and implementation of the technology is planned, there are still a number of challenges and uncertainties related to the technique. It is generally accepted that the effects of low-salinity waterflooding are caused by wettability alteration, but the processes involved are still not fully understood.

Heriot-Watt University has been conducting research to investigate the mechanisms of interactions between low-salinity water, crude oil, and porous media at reservoir conditions. Industry support for the work was secured through Industry Technology Facilitator (ITF), and professor Mehran Sohrabi, director of the Center for Enhanced Oil Recovery (EOR) and CO2 Solutions at the university, is leading the project team.

Low-Salinity Water Injection

Waterflooding improves oil recovery by displacing oil, and injection water is usually taken from the nearest available source (which is seawater for most offshore fields). The first effects of low-salinity water injection were published in the 1990s, when work at the University of Wyoming indicated that injecting water with a total dissolved-solids content of less than 5,000 ppm resulted in a higher oil recovery than that attained by injecting high-salinity water such as seawater. Since then, a number of studies with varying results have been published, and the recovery benefits described are likely to be field-dependent.

Low-salinity waterflooding has a number of potential benefits. It has relatively low costs compared with other techniques. It can be implemented in ongoing and new waterflood projects onshore and offshore and has shown potential for sandstone and carbonate reservoirs. In addition, it can be used alone or in conjunction with other EOR techniques, e.g., polymer injection, as a technology enabler. It also can alleviate problems associated with conventional waterflooding, such as scale formation and souring.
Borehole Imaging Technology Visualizes Photorealistically in Oil-Based Muds
Authors: Laronga Robert J. , Shalaby Ehab
Published: February 2015

Technology Update

To estimate reserves, optimize well recovery, and place future development wells more accurately, operators require increasingly detailed understanding of complex oil and gas reservoirs. High-resolution geological data from the borehole— core samples and wireline microresistivity images—are essential to fully characterize reservoir architecture, guide and constrain reservoir models, and make timely decisions with precision and confidence.

In unconventional resource plays, for example, geologists need to observe complex natural fracture systems, measure fracture density and direction, determine in-situ stresses, and calculate pressures required to initiate and propagate optimal hydraulic fracturing. In high-cost deepwater environments, exploration teams need to interpret a wide variety of sedimentary facies. Reservoirs often consist of thinly laminated sands or channels, which demand high-definition methods for visualization and interpretation. Typically, deepwater formations exhibit very low resistivities— from 1 ohm-m in shales to as low as 0.2 ohm-m in water-bearing sands.

Operators often use whole cores to identify subtle sedimentary facies, but cores can be expensive and time-consuming to acquire. Thus, core samples are usually obtained only in select wells and in the most critical intervals. The resulting lack of geological detail can adversely affect reservoir analysis, interpretation, and modeling.

On the other hand, microelectrical borehole images can be acquired continuously over the openhole interval at any depth or in any formation, with relative ease. Until recently, high-definition borehole imaging has been possible only in electrically conductive water-based muds (WBM). However, most deepwater wells and many unconventional shale wells today are drilled with high-performance, nonconductive oil-based muds (OBM).

Legacy OBM borehole imaging tools, which were introduced in the last decade, are a significant technical advancement over the preceding dipmeter tools but still exhibit certain limitations. For example, spatial image resolution in OBM is nowhere near the quality obtained from WBM imagers. The lack of circumferential coverage of the borehole leaves large gaps that must be filled by inference.
Pushing the Frontier through Wellbore Strengthening
Authors: Jacobs Trent
Published: February 2015

Drilling Fluid Technology

Making hole has become a more difficult and complex operation as operators move into untapped horizons, especially deepwater and unconventional fields. It is this increased difficulty that is driving a growing number of companies to invest millions of dollars in advanced materials that seek to make drilling wells easier. The technologies many are working on involve not mechanical systems, but advanced chemistry and physical science. Some are using nanoparticles and others are reworking older technologies by adding new substances, all in an effort to make the undrillable drillable.

Those reaching for this prize include teams of university researchers, young technology startups, and established firms that are buying intellectual property from others so they can join the race. Different groups are designing drilling-fluid additives and other materials that they claim make unstable wellbore walls stronger by preventing and sealing fractures as the drill bit eats its way down to the pay zone.

The importance of these wellbore-strengthening objectives is well understood by drillers who have suffered sudden losses of drilling fluids into the rock formation through fractures, which can lead to gas kicks and catastrophic blowouts, or those who have had to deal with stuck pipe because of a collapsed borehole. For petroleum engineers, preventing these problems with new technology means they can design simpler, cheaper, and safer wells with fewer casing strings. For the boardroom, wellbore strengthening means executives can promise better returns and higher flow rates to investors because large-diameter casing strings can be placed into the production zone. And for the industry in general, wellbore strengthening means wells that many consider too dangerous or too hard to drill may soon become tamed.

Clay-Stabilizing Nanoparticles for Water-Based Drilling Fluids

In April, downhole chemical technology provider Flotek Industries acquired water-based, drilling fluid-additive technology from ARC Drilling Fluids. Flotek hopes to use the technology, which it markets as Microsolutions, in areas where using oil-based drilling fluids have traditionally been the only option. Drilling fluids that use water as a base are far cheaper than oil-based fluids, making them more desirable, but oil is less reactive with many rock formations.

Wellbore Strengthening: The Mechanical Option

Before many of the new chemical and nanoparticle technologies for wellbore strengthening arrived to the marketplace, casing while drilling (CWD) was used for more than a decade to mechanically achieve the same end. Weatherford International and other service companies have developed multiple technologies for CWD, as well as the similar method of liner drilling (LD). With CWD, the casing is the drillstring, and with LD, the liner is the drillstring.
Oil Tests at Extreme Conditions Yield New Data For Reservoir Modeling
Authors: Rassenfoss Stephen
Published: February 2015

HP/HT Research

Drilling in the extremely deep waters of the US Gulf of Mexico has revealed huge oil reservoirs, and gaps in the industry’s capabilities.

While much attention has gone toward creating high-performance equipment to develop and produce oil from high-pressure/high-temperature (HP/HT) formations such as the Lower Tertiary, researchers around the world have been quietly working on measuring how oil behaves under those extreme conditions.

“New tools are needed to represent reservoir fluid properties at temperatures from subsea (~30°F) to the reservoir temperatures near 400°F and pressures ranges from ambient to 30,000 psi,” said Jefferson Creek, a senior research consultant at Chevron Energy Technology. “Developing numerical representations requires a solid base of appropriate measured data to benchmark performance of new equations or new procedures.”

A study organized and backed by the National Energy Technology Laboratory (NETL) of the United States Department of Energy first looked to see if any laboratory had tested how oil performs at really high pressures and temperatures.

“The bottom line is there are huge gaps in data in high-temperature reservoirs where they are already producing,” said Robert Enick, a research professor at the University of Pittsburgh, one of the lead researchers on the NETL project.

One reason for the gap was the lack of equipment capable of making those measurements and the obstacles facing anyone who wanted to build it. It is extremely tough to prevent leaks at those pressures, and the usual measurement methods do not work because sensors cannot survive at those temperatures. The devices they created to do the job showed that the formulas commonly used at lower temperatures and pressures are a poor fit once the temperature exceeds 300°F.

When commonly used models were used to extrapolate those properties under HP/HT conditions, density predictions were off by as much as 50%, and viscosity errors were as high as 75%, according to a project presentation. Based on multiple HP/HT density and viscosity tests of components that make up crude oil, equations were identified that offered a good correlation to the data. By tweaking some of the parameters in those equations it was possible to get a closer fit with the test results.

Now the results are being passed on to the large oil companies working in ultradeepwater.
The Power of the Industrial Internet: Turning Data Into Insight and Action
Authors: White Paul
Published: February 2015

Talent & Technology

Over the past 200 years, since the days of the Industrial Revolution, we have experienced several waves of innovation, which have had a profound effect on our everyday lives. Today, across the oil and gas industry, we are on the cusp of a new transformative era, with the potential to radically change the way we do business and interact not just with the physical world, but also with the world of analytics.

In the latter part of the 18th and early part of the 19th centuries, the Industrial Revolution represented the first wave of advancement, with innovation and technology primarily applied to agriculture, manufacturing, and energy production. It delivered a period of unprecedented growth and changed people’s lives significantly.

The second wave took place at the end of the 20th century, at a much faster rate—over a period of approximately 50 years—and was characterized by the emergence of the Internet. With fewer than 300 computers connected in 1981, that earliest manifestation is unrecognizable to today’s, where connectivity is almost ubiquitous and the Internet is responsible for providing billions of people with instant access to massive amounts of information, changing the way we shop, socialize, and execute much of our business.

Today, we are experiencing a third wave, the emergence of the “industrial Internet,” a place in which the physical and analytical worlds collide. The industrial world is being digitized and reshaped by “big data,” opening up new and unprecedented levels of productivity. Data coupled with expertise- driven knowledge are important to a company’s ability to achieve improved outcomes.

Essentially a convergence of machines and intelligent data, the industrial Internet is enabled by advanced computing, data analytics, low-cost sensing, and new levels of connectivity, all permitted by the Internet. It is a deep meshing of the digital world with the world of equipment and machines; one that, by 2020, will see an estimated 50 billion devices connected and communicating, not only with their owners, but also with each other. This revolution holds the potential to bring about a profound and significant transformation of global industry and, in turn, changes to many aspects of daily life, including the way we work.

A large proportion of the devices connected to the Internet now are smartphones, tablets, and computers. In the future, almost all technically active devices will be connected to the Internet, limited not just to a range of consumer devices such as TVs or refrigerators, but also including a broad range of industrial equipment, such as gas turbines, wind turbines, and the full range of subsea systems.
Technology Focus: Offshore Production (November 2014)
Authors: Thomas Sally A.
Published: February 2015

Technology Focus

 

Shallow-water offshore production began before 1900 and continues to be important today. Technology to maximize economic production from shallow-water fields can be adapted from onshore or deepwater technologies. Improvements in monitoring-system capabilities (and costs) are direct contributors to optimizing well and facilities operations. Several case studies illustrate the benefits of applying existing technology to increase production in mature operations.

The first case study is of a gas/condensate field. Typical liquid-handling strategies were first applied to mitigate production decline, including converting the test separator to a low-pressure separator. Regular well testing is required for allocation and reservoir management. Previously, low-pressure wells were shut in during the well tests, resulting in production losses. Clamp-on sonar meters allow well testing every 2 months without shutting in production. Data from the sonar metering and other production-surveillance techniques have been used to optimize well cycling.

The second case study describes implementation of through-tubing technology for sand control at a normally unmanned platform. The platform is located in shallow water with onerous sea states. Significant sand production began from an unconsolidated oil zone when the original gas well was converted to commingled production. This paper describes the selection and installation of through-tubing sand control and subsequent selection and installation of through-tubing gas lift. Critical success factors for well rejuvenation at this marginal field include managing marine issues and crane limits.

The last case study discusses installation of a downhole electric heater in an offshore heavy-oil well. Heating heavy-oil reservoirs is uncommon offshore. This successful heater application uses a three-phase system with a cold section to protect the electrical submersible pump (ESP) used to lift the oil. Distributed-temperature sensing monitors temperature profiles in the well. Cable connections—power for the heater and the ESP—are critical for successful operation. JPT

Recommended additional reading at OnePetro: www.onepetro.org.

IPTC 16858 Downhole Electrical Heating for Heavy-Oil Enhanced Recovery: A Successful Application in Offshore Congo by F. Bottazzi, Eni, et al.

OTC 23948 Full-Scale Testing of Distributed-Temperature Sensing in Flexible Risers and Flowlines by Nick Weppenaar, NOV Flexibles, et al.

OTC 23968 Large-Diameter-Riser Laboratory Gas Lift Tests by G. Zabaras, Shell, et al.
Sonar Metering Optimizes Production in Liquid-Loading-Prone Gas Wells
Authors: Carpenter Chris
Published: February 2015

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 166652, ’Use of Sonar Metering To Optimize Production in Liquid-Loading-Prone Gas Wells,’ by C.A. Shields and M. Dollard, Marathon Oil UK, and S. Sridhar, G. Dragnea, and M. Illingsworth, Expro Meters, prepared for the 2013 SPE Offshore Europe Oil and Gas Conference and Exhibition, Aberdeen, 3-6 September. The paper has not been peer reviewed.

This paper discusses the use of clamp-on sonar flowmeters to minimize losses associated with well testing and to gain the subsequent benefits seen with respect to production optimization and well deliquefication. Clamp-on sonar flowmetering is a nonintrusive technology that measures the flow velocity of the fluid stream. This intensive well-management strategy has assisted in reducing the production decline of the East Brae field in the North Sea.

Introduction

The East Brae platform (Fig. 1) is located 275 km northeast of Aberdeen in Block 16/3a in a water depth of 110 m. The reservoir comprises high- permeability sands deposited by turbidity currents. The reservoir has an average porosity of 17% and an average permeability of 558. md. The platform initially started producing condensate, while reinjecting the gas, in December 1993. Exporting of the gas began in 1994, and reinjection was phased out. The current topside holds a low- pressure (LP) separator (test separator) operated at 217 psig, a high-pressure (HP) separator (first-stage separator) currently operated at 406 psig, and second- and third-stage separators. It also includes a gas-processing and - dehydration plant, three gas-compression trains, and produced-water-processing facilities for discharge into the sea.

There are currently 12 producing monobore wells on the East Brae platform. Former gas-injection wells have now been converted to producing wells. The wells are inclined up to a maximum deviation of 45°. The reservoir fluid is a retrograde gas condensate that exhibits compositional variation with depth. The reservoir has an active aquifer that has encroached into the producing layers as reservoir pressure has depleted through production.

Background: Allocation and Well Testing

On the East Brae platform, production allocation for the wells has typically been carried out by individual well tests of each well in the test separator on a monthly basis. The well test records the amount of oil and gas produced from a well during the first stage of separation. The oil and gas are then processed further in the plant. Some of the oil is vaporized into the gas phase as it is stabilized in lower-pressure separators, and some of the gas is liquefied as it is cooled and compressed. As a result of these equilibrium changes, the oil and gas rates exported from the platform (known as its “potentials”) that are attributable to a single well are not directly comparable with the oil and gas rates measured at the test separator for that well.
Identification of expressed resistance gene analogs (RGA) and development of RGA-SSR markers in tobacco
Authors: Yuan Qinghua , Xie Ruihong , Zhang Zhenchen , Ma Zhuwen , Li Jiqin , Li Shuling , Chen Junbiao , Lü Yonghua
Published: February 2015

Tobacco is an important cash crop and an ideal experimental system for
studies of plant-pathogen interactions. Identification of tobacco resistance
(R) genes and resistance gene analogs (RGAs) is propitious to elucidate the
underlying resistant mechanisms. In recent years, the public tobacco EST
(expressed sequence tags) data set, which provides a rich source for
identifying expressed RGAs, has enlarged substantially. In this study, 149606
Uni-ESTs were assembled from 412325 tobacco ESTs available in GenBank,
scanned with 112 published plant R-genes protein sequences, and 1113
Nicotiana (tobacco) RGAs (NtRGAs) were identified. The majority of them
comprised the common R-genes domains, such as NBS-LRR, LRR-PK, LRR, PK and
Mlo, while we were unable to identify 109 RGAs using published domains of
R-genes. Upon sequence alignment, 1079 NtRGAs were allocated on 712 loci
within the Nicotiana benthamiana genome. A total of 78 simple sequence
repeats (SSRs) were identified from 72 NtRGAs, and out of 64 newly designed
primer pairs, 54 primer pairs generated clear bands upon PCR amplification
using tobacco genomic DNA. Only nine primer pairs displayed polymorphism in
24 varieties of tobacco, with 2-4 alleles per locus (2.56 alleles on
average), while 41 primer pairs were able to detect polymorphisms in six wild
species of genus Nicotiana, with 2-4 alleles per locus (2.61 alleles on
average).
Levitin-polyakwell-posedness for set-valued optimization problems with constraints
Authors: Chen Jiawei , Cho Yeol , Ou Xiaoqing
Published: February 2015

In this paper, Levitin-Polyak well-posedness for set-valued optimization
problems with constraints is introduced. Some sufficient and necessary
conditions for the Levitin-Polyak well-posedness of these problems are
established under some suitable conditions. The equivalence between the
wellposedness of optimization problems with constraints and the existence
and uniqueness of their solutions are proved. Finally, we give some examples
to illustrate the presented results.
Common fixed point results in complex valued metric spaces with application to integral equations
Authors: Hussain N. , Azam Akbar , Ahmad Jamshaid , Arshad Muhammad
Published: February 2015

In this paper, common fixed point of six mappings satisfying a contractive
condition involving rational inequality in the framework of complex valued
metric space are obtained. Moreover, some examples and applications to
integral equations are given here to illustrate the usability of the obtained
results.
A second order differential equation with generalized Sturm-Liouville integral boundary conditions at resonance
Authors: Du Zengji , Yin Jian
Published: February 2015

By using Mawhin coincidence degree theory, we investigate the existence of
solutions for a class of second order nonlinear differential equations with
generalized Sturm-Liouville integral boundary conditions at resonance. The
results extend some known conclusions of integral boundary value problem at
resonance for nonlinear differential equations
A Serrin type criterion for incompressible hydrodynamic flow of liquid crystals in dimension three
Authors: Huang Bingyuan
Published: February 2015

In the paper, we establish a Serrin type criterion for strong solutions to a
simplified densitydependent Ericksen-Leslie system modeling incompressible,
nematic liquid crystal materials in dimension three. The density may vanish
in an open subset of ?. As a byproduct, we establish the Serrin type
criterion for heat flow of harmonic map whose gradients belong to Lrx Lst,
where 2/s + 3/r ? 1, for 3 < r ? ?.
A note on closedness and connectedness in the category of proximity spaces
Authors: Kula Muammer , Maraşlı Tuğba , Özkan Samed
Published: February 2015

In this paper, an explicit characterization of the separation properties T0
and T1 at a point p is given in the topological category of proximity spaces.
Furthermore, the (strongly) closed and (strongly) open subobjects of an
object are characterized in the category of proximity spaces and also the
characterization of each of the various notions of the connected objects in
this category are given.
On generalized spiral-like analytic functions
Authors: Noor Khalida , Khan Nazar , Noor Muhammad
Published: February 2015

In this paper, we use the concept of bounded Mocanu variation to introduce a
new class of analytic functions, defined in the open unit disc, which unifies
a number of classes previously studied such as those of functions with
bounded radius rotation and bounded Mocanu variation. It also generalizes the
concept of ?-spiral likeness in some sense. Some interesting properties of
this class including inclusion results, arclength problems and a sufficient
condition for univalency are studied.
Convergence theorems for Bregman strongly nonexpansive mappings in reflexive Banach spaces
Authors: Zegeye Habtu
Published: February 2015

In this paper, we study a strong convergence theorem for a common fixed point
of a finite family of Bregman strongly nonexpansive mappings in the framework
of reflexive real Banach spaces. As a consequence, we prove convergence
theorem for a common fixed point of a finite family of Bergman relatively
nonexpansive mappings. Furthermore, we apply our method to prove strong
convergence theorems of iterative algorithms for finding a common zero of a
finite family of Bregman inverse strongly monotone mappings and a solution of
a finite family of variational inequality problems.
Fatal Congenital Hypertrophic Cardiomyopathy and a Pancreatic Nodule Morphologically Identical to Focal Lesion of Congenital Hyperinsulinism in an Infant with Costello Syndrome: Case Report and Review of the Literature
Authors: Sheffield Brandon S. , Yip Stephen , Ruchelli Eduardo D. , Dunham Christopher P. , Sherwin Elizabeth , Brooks Paul A. , Sur Amitava , Singh Avash , Human Derek G. , Patel Millan S. , Lee Anna F.
Published: February 2015

Costello syndrome is characterized by constitutional mutations in the proto-oncogene HRAS, causing dysmorphic features, multiple cardiac problems, intellectual disability, and an increased risk of neoplasia. We report a male infant with dysmorphic features, born prematurely at 32 weeks, who, during his 3-month life span, had an unusually severe and ultimately fatal manifestation of hypertrophic cardiomyopathy and hyperinsulinemic hypoglycemia. Molecular studies in this patient demonstrated the uncommon Q22K mutation in the HRAS gene, diagnostic of Costello syndrome. The major autopsy findings revealed hypertrophic cardiomyopathy, congenital myopathy, and a 1.4-cm pancreatic nodule that was positive for insulin expression and morphologically identical to a focal lesion of congenital hyperinsulinism. Sequencing of KCNJ11 and ABCC8, the 2 most commonly mutated genes in focal lesion of congenital hyperinsulinism, revealed no mutations. While hyperinsulinism is a recognized feature of RASopathies, a focal proliferation of endocrine cells similar to a focal lesion of hyperinsulinism is a novel pathologic finding in Costello syndrome.
Acute Thymic Involution in Unexplained Third Trimester Stillbirth: Frequency, Grade, and Correlation with Neuropathologic Injury
Authors: Jacques Suzanne M. , Kupsky William J. , Qureshi Faisal
Published: February 2015

Many 3rd-trimester stillbirths are unexplained, including the time course of the illness. Histologic acute thymic involution (ATI), when graded, correlates with duration of acute illness (grade 0, <12 hours; grade 4, >72 hours). Histologic brain injury is also common in stillbirth. We investigated ATI in unexplained stillbirth and correlated it with neuropathologic injury by identifying 58 autopsies of unexplained, 3rd-trimester stillborns (preterm, n = 24; term, n = 34) that included brain examination and graded ATI from 0 (resting state) to 4 (pronounced lymphodepletion). Gray matter injury (GMI) and white matter injury (WMI) were classified as older, recent, or absent, and ATI was correlated with GMI, WMI, thymic weight, and clinical data. Nine cases (16%) had ATI grade 0–1; 19 (33%), grade 2; 24 (41%), grade 3; and 6 (10%), grade 4. Older GMI and WMI were present in 39 (67%) and 10 (17%) stillborns, respectively. Higher ATI grade correlated significantly with older GMI ( P < 0.001) and WMI ( P = 0.014). The ATI grade was higher in the small-for-gestational stillborns compared with the appropriate- or large-for-gestational stillborns ( P = 0.017) but did not correlate significantly with gestational age or other clinical or demographic factors evaluated. The ATI grades 2–4 were found in 84% of the stillborns, consistent with onset of acute illness between 24 and >72 hours before demise. Higher ATI grade correlated significantly with older brain injury, suggesting similar time of onset and shared underlying pathophysiologic events, the specific nature of which remains unclear.
Considering the Effects of Gender in Child-Robot Interaction Studies: Comment on Srinivasan, et al. (2013)
Authors: Laue Cheyenne L.
Published: February 2015

Using a pretest-posttest design, Srinivasan, et al. (2013) found that a period of interaction between children and an Isobot humanoid robot improved performance on standardized measures of imitation, planning, and execution of motor behaviors. The authors conducted their study with 15 typically developing children (9 boys, 6 girls) and 1 boy with autism. All participants were between the ages of 4 and 7 years. While considerations of gender expectations, norms, and appearance are now considered critical to social interactions between humans and robots by most researchers in the field of human-robot interactions, Srinivasan et al. did not consider these effects. This paper proposes that gender could have significant effects on the results of future work conducted in this area.
An Exploratory Study on School Children's Intent Attributions for Parental Structuring Behaviors
Authors: Zhang Lufei , Wan Wendy W. N. , Tam Vicky C. W. , Wu Peiguan , Luk Chung-Leung
Published: February 2015

This paper begins by proposing a theory-driven, two-dimensional model of children's intent attributions for parental structuring behaviors. The two dimensions are parent-centered intents vs child-centered intents and instrumental goals vs social-emotional goals. These two dimensions imply four categories of intent attribution for parental structuring behaviors. An exploratory study was conducted to examine school children's intent attributions for parental structuring behaviors. Responses in the four proposed categories were observed. Additionally, two new categories emerged from the data: parental structuring behaviors for the sake of the parents' intangible benefits and parental structuring behaviors for the sake of social interests. Research implications of these findings are discussed.
Is Intraindividual Variability Different between Unimanual and Bimanual Speed-Accuracy Movements?
Authors: Mickevičienė Dalia , Skurvydas Albertas , Karanauskienė Diana
Published: February 2015

Dominant (right) and nondominant (left) hand differences in motor performance variables were investigated during targeted rapid aiming unimanual and bimanual (to two separate targets) speed-accuracy tasks. The performance of the dominant and nondominant hands were compared during rapid targeted unimanual and bimanual reaching tasks (50 repetitions) in adult, neurologically intact, right-handed men ( n = 20). As task difficulty increased from unimanual to bimanual tasks, reaction time increased and velocity (average and maximal) of performance decreased significantly. The effect of hand was significant only on average movement velocity and on intraindividual variability of accuracy (in both cases performance in the left hand was worse). Variability of movement path (accuracy) was less in the right hand during both unimanual and bimanual tasks.
Juridical Tools of Governmental Nature Used to Mitigate Various Difficulties of the Financial and Budgetary System
Authors: Bostan Ionel
Published: February 2015

The lack of supervision and thorough regulation of the financial system, by virtue of the exercise of the principle of laissez-faire, is likely to lead to imbalances with destructive consequences on the standard of living and savings of the population. The global crisis which started in 2007 is the most illustrative example in this regard. This has highlighted the inability of the regulatory and supervisory institutions to adapt to the realities of the market. As a result, nowadays authorities are still concerned with restoring the balance between the freedom of the markets, firms and financial products and their appropriate regulation. The anticipated result: the installation of the sustainable growth. This requires the existence of a more transparent financial system, with severe rules in accounting/accounting reporting of assets and a mechanism for ensuring the integrity of the financial markets. We must assert that lately there has been a certain intensification of the intervention of the executive authority/government by juridical means (government ordinances and decisions) in the economic and business system, due, as we will show, to the deterioration of the financial problems. Therefore, in this paper we seek to emphasize the specific manner in which the national executive authority was involved in the direction shown. Obviously, we address the topic from the perspective of the economic and financial legislation, also considering the budgetary aspects and, to some extent, certain elements of impact. To this end, we used the most recent law and economic/financial bibliography, reports issued by prestigious specialized institutions and also the substantiation notes drafted by the governmental factors when adopting normative acts of the type described above, as the issue in question concerned us over the last five years.