bluuebunny/crossref_metadata_2025 huggingface dataset:
Briefing: Potential for seawater district heating and cooling in the UK
Authors: Goodier Chris I. , Chmutina Ksenia , Poulter Elliot , Stoelinga Paul
Published: May 2013

The main source of the energy used for space heating in the UK built environment is gas. However, more sustainable and efficient sources could be employed that would not only contribute towards achieving the UK’s carbon dioxide targets but would also benefit the nation’s energy security. One alternative way of generating energy more efficiently is by the use of heat pumps, of which there are various types depending on the source of the heat and the sink utilised for the heat. One such source is seawater, and examples of seawater heating and cooling systems have been successfully implemented in several parts of the world. Presented here is a comparison of a seawater heating system in The Hague, the Netherlands, and another in Portsmouth continental ferry port, UK. Based on these comparative cases, together with discussions with district heating specialists, this paper briefly debates the current drivers and barriers for the future of seawater heating systems in the UK. It emphasises that as well as the financial and technical obstacles, governance barriers have also to be overcome.
Degradation characteristics of foamed concrete with lightweight aggregate and polypropylene fibre under freeze–thaw cycles
Authors: Tan Xianjun , Chen Weizhong , Tian Hongming , Yuan Jingqiang
Published: May 2013

The growing use of foamed concrete for building materials and geotechnical fills raises the question of suitable durability and performance standards. In order to analyse the degradation characteristics of foamed concrete with lightweight aggregate and polypropylene fibre under freeze–thaw cycles, specimens are frozen and thawed in a temperature and humidity-controlled container where the temperature varied from +40 to −40°C and the humidity was kept constant (about 100%). The freeze–thaw tests are performed; they consist of around 40 cycles of freezing and thawing, with each cycle lasting 8 h. The deterioration of the specimens is examined according to changes of strength and deformation characteristics in a series of uniaxial compression tests. The experimental results show that: (a) the compressive strength of samples decreases and the axial strain corresponding to the peak stress increases with increasing of freeze–thaw cycles, and the compressive strength decays exponentially with the number of freeze–thaw cycles; (b) the compressive strength of foamed concrete decreases with increase in foam and perlite content, increases with increased polypropylene fibre content; their fitting relationship is also provided.
Flexural fatigue behaviour of concrete under uniaxial and biaxial stress
Authors: Kim Jihwan , Yi Chongku , Lee Seung-Jung , Zi Goangseup
Published: May 2013

The main objective of this investigation was to study the effect of stress states on the flexural fatigue behaviour of concrete. The fatigue behaviours obtained from different test methods were compared, including the recently developed biaxial flexure test, ASTM C 1550 and four-point bending test. Fourteen specimens were cast and tested for each test method, under both monotonic and repeated loadings. The fatigue strength was compared with those recommended by existing design codes. Test results showed that there were no significant differences in the flexural fatigue behaviours under different stress states (i.e. uniaxial and biaxial). These results suggest that the uniaxial flexural tensile fatigue strength of concrete may be adopted for the design of concrete components subjected to biaxial flexural tensile fatigue loading.
Tracking System, Failure Analysis and Reuse Program To Optimize Usage of Power Cable in Electrical Submersible Pumping Systems
Authors: Rubiano E.. , Vargas H.. , Martin J. L.
Published: May 2013

In an electrical submersible pumping system, power cable has a big impact in cost and performance; reuse procedures are established based on electrical test only, not based either on run life of the cable or number of running of the system. In Llanos Norte field in Colombia, OXY started a process to reuse power cable as an optimization cost process with good results, having in mind motor amperage, electrical test results, number of runnings, conductor size, and some other important variables which affect power cable performance.

As a second phase of optimization, failure analysis of cable presented a main issue to solve, because it is not easy to track power cable failures due to sometimes the cable used becomes spliced in many parts. Also, if the cable is reused adds an additional difficulty to the process; so, tracking is a key factor for success.

This paper contains successful story of tracking system, failure analysis and reuse program in Caño Limón as an optimization process to improve cost without affecting electrical submersible pumping systems run life and performance, including lessons learned and good practices.
Design of a Laboratory for Intermittent Gas-Lift and Study of the Dynamic Behavior of Its Components
Authors: Lara Ismael Orlando , Bordalo Sergio N.
Published: May 2013

Despite the advances achieved so far, some important aspects of the operation of the conventional intermittent gas-lift (IGL) remain unexplored or poorly studied, as for instance, the concurrency of cycle stages, as presented by Carvalho (2004), or the stability of cycles due to motor valve timing and adjustment of the gas-lift valve. At the same time, the Zadson pneumatic pump (ZPP) has presented good results in Brazilian fields, motivating studies to develop computational simulators for the design of this method. In the course of the present work, a physical simulator was built for the IGL and ZPP, to validate numerical simulators proposed by previous authors. The laboratory apparatus consists of three operational sets, the first set represents the well-reservoir coupling, the second set is the injection system of compressed gas and the third set is a collection of columns of production of the conventional IGL and ZPP. For measurement, there are pressure transducers located at various points of the laboratory apparatus and tanks for measuring the produced volume. The system of data acquisition and actuation of the gas-lift and motor valves are controlled by a microcontroller board. Tests were performed by changing the operating variables. As conclusions of the study the concurrent stages during the IGL cycle were identified, the fallback was rated for various operating conditions, the stability of the IGL cycles was studied, and an operating map of the conditions of a stable IGL cycle was drawn. In addition, three operating modes of the ZPP were tested.
Progressing Cavity Pumps In Light Oil: Successfully Expanding the Application Envelope Through Best Practices and Lessons Learnt
Authors: Jahn Sheldon , Baldwin Brett
Published: May 2013

The Progressing Cavity Pump (PCP) applications continue to expand from heavy and medium into light oil applications. The benefits include lower capital cost, less visual impact, smaller footprint and decreased operational costs primarily as a result of the high mechanical efficiency of a PCP. The difference between premature failure and long-term success can be minimized by following best practices and lessons learnt from 20 years of experience evaluating thousands of wells. Light oil usually has a high percentage of Mono-Aromatics of which the most common are Benzene, Toluene, and Xylene (BTX). The molecular structure of BTX enable it to attack or attach onto the elastomer, causing aggressive swelling and softening. Light oil is usually found at deeper, warmer reservoirs causing the BTX to be more active and aggressive while also reducing the mechanical strength of the elastomer. H2S and CO2 can also be associated with light oil and have adverse effects on the elastomer. This paper will discuss how to gather important data, sort information, select equipment and provide operational guidelines to improve the overall success of PCP’s in light oil.
Improving the Reliability and Maintenance Costs of Hydraulically Actuated Sucker Rod Pumping Systems
Authors: Phillips W.. , Mehegan L.. , Hernandez J..
Published: May 2013

Hydraulically actuated sucker rod pumps have been around since the 1940’s but have not received a widespread adoption or acceptance on the order of beam pumps, ESP’s or PCP’s. This is in no small part, due to a reputation of high maintenance costs and frequent failures. Innovations in hydraulically actuated sucker rod pumps, with a keen insight for the oilfield environment, have helped improve reliability and reduce maintenance costs. Among these improvements are the elimination of persistent external hydraulic leaks, a long-stroke capability, and a simplified control system. The instrumentation and control of the hydro-mechanical system is accomplished with an innovative method for determining both polished rod position and load based solely on the hydraulic fluid dynamics. This eliminates any sensors, or points of failure, at the wellhead. Vast improvements in control and data acquisition have greatly reduced the failure rates of hydraulic sucker rod pumping systems by automatically responding to adverse conditions. By allowing operators to remotely interact and troubleshoot the system, a finer grained level of optimization can be achieved by closely matching the wells inflow to the production rate. In some down-hole failure cases, such as a stuck pump, a unique advantage of a hydraulic system allows the operator to attempt unsticking the pump by overloading the polished rod. Although this procedure is not always successful, it does provide a last resort that may save the cost of pulling the well. This procedure is unique to a hydraulic system because there are no structural or reducer load limitations beyond that of the rod-string capacity. The long-stroke improves down-hole equipment runtimes by distributing the wear over a larger surface and by reducing the cyclic fatigue on the rod-string. While the hydraulically actuated sucker rod pump is not appropriate for every well, it does offer significant advantages in those wells where it is suitable. These advantages include long-stroke capability, remote optimization, and safe operation in terms of no external moving parts. The complete system is simple, cost effective, and portable, making it ideal for both permanent and trial installations.
Experimental Study of Centrifugal Pump Handling Viscous Fluid and Two-Phase Flow
Authors: Paternost G. M. , Bannwart A. C. , Estevam V..
Published: May 2013

This paper presents an experimental study about the performance of a centrifugal pump as a function of the liquid viscosity and intake free gas fraction. The first part evaluates a pump performance map proposed by Tulsa University Artificial Lift Projects (TUALP) for single-phase flow using dimensionless numbers, which considers the fluid properties, flow rate, rotational speed and pump head for a generic centrifugal pump. The second part analyses the pump performance parameters under different liquid viscosities and free gas fractions, proposes a modification in the TUALP procedure based on well-know dimensionless numbers, and suggests an extension of the analysis to incorporate the effect of the free gas fraction on the pump performance.
The Effect of Temperature on the Mechanical Pump Slippage in Heavy Oil Wells With Steam Injection
Authors: Benavides Diaz L. C. , Chacon A. Gil , Ortiz J..
Published: May 2013

In the last two decades the participation of heavy oils in the global volumes of production of oil has been constantly increasing and so the requirement for the development and adjusts of the existing technologies within the different stages of the extraction process of the petroleum.

For the specific case of the production of these oils to achieve the goal of making this flow economically viable up to the Surface is normally the bigger risk with their high viscosity being the main risk. In this way the use of the cyclic injection of steam is the improved and most commonly used method of recovery which increases the temperature of the oil and decreases its viscosity while allows an easier extraction of the resource.

Therefore a research was developed showing how the change of temperature decreases the efficiency of the pump due to the increase of the slippage which in turn is due to drop in the viscosity of the oil and, like in some wells, depending on the permeability of the sand a peak is shown in the efficiency at the beginning of the production because of a momentary pressurization of the well. All this based on slippage formulas developed by different authors, lab tests and field data acquired in the Zone of Moriche, municipality of Puerto Boyacá, where the steam injection is currently used for the extraction of petroleum.

Finally, these data were the start point to develop a new design of pump which adapts to the temperature changes and is more efficient under the conditions of steam injection than the conventional pumps, all this seeking the optimization of the petroleum extraction process in the industry.
Spatial Well Surveillance : An Approach For Early Detection of Well Behavior in Highly Populated Fields
Authors: Hidalgo J. G. , Ataguile S.. , Bertomeu F..
Published: May 2013

Nowadays, supporting systems are scattered with several applications, some of them are custom developed, generating redundant and inconsistent data stores and silos across engineering, geo-science and operational domains, making it extremely difficult to access and effectively use data or information. An opportunity exists –by combining the industry’s monitoring and instrumentation capabilities with spatial data management and predictive analytics– to provide real-time operational intelligence, resulting in improved decision making.

This project outlines the development and implementation of a Geo Portal designed to provide information about wells behavior based on Production and Automation Data. The term Geo Portal refers to a map-based visualization tool that enables analysis of complex spatial and tabular data from a user friendly and intuitive web interface, enabling the user to analyze and understand vast amounts of data to make better and faster business decisions.

Through the Geo Portal it is possible to: View active and inactive pumping units and theirs technical characteristics.Verify the last time a well test was madeVisualize wells test rate differencesAnalyze the distribution of wells in downtimeLook at Production bubble mapsProvide online Diagnosis of pumping status (Combined KPI from Fluid above pump, pump efficiency and others)

The significance of this is that the integration enables an interface for quick, intuitive information retrieval. From an operational perspective, it is a great opportunity to manage field resources with focus on efficiency and maximizing production. Also, it is easy to identify opportunities for field foremen or field managers.
Improving Well Performance with Multiphase Helicoaxial Pump in Wells with High Gas to Liquid Ratio
Authors: Fidani C.. , Peralta M. Belen , Nuova L.. , Gould M. Sanchez
Published: May 2013

As the number of mature reservoirs continues to increase worldwide, so has the development of new technologies to aid electrical submersible pump (ESP) performance. Because depleting fields produce increasing gas volume, gas separators and gas handlers are necessary to maintain pump performance and production.

In wells with high gas volume, production is limited by the centrifugal pump’s ability to handle gas. Centrifugal pumps suffer from a head degradation and gas-locking in the presence of high percentages of free gas. Different technologies have been implemented to help operators achieve their production goals. However, as downhole conditions continue to change, the gas-handling capability of the technology installed becomes insufficient, resulting in downtime due to gas-lock, limited drawdown, high operational costs, high motor current fluctuations, and others issues.

A multiphase helicoaxial pump installed below the main production pump allows the production pump to efficiently handle higher percentages of free gas and up to 75% of gas volume fraction (GVF) at the first stage. This system is designed to improve stability in gassy wells, provide better slug handling in horizontal wells, increase the production rate and recovered reserves, and increase ESP effectiveness.

To enhance production in oil wells experiencing gas-locking problems, an operator began optimizing downhole ESPs where they showed unstable operational behavior and where the GVF was overcoming the maximum gas- handling capability of centrifugal pumps (up to 45% GVF).

In the first optimized ESP wells, the operator was able to increase production by reducing gas-locking production shutdowns, to stabilize motor current fluctuations, and to Increase production and reservoir life by increasing drawdown and allowing effective pump operation at lower intake pressure.

By the end of 2010, a total of 10 wells were operating with this technology within three different fields. Currently, more than 25 wells have been optimized.

The implementation of this technology in wells with high GLR has been demonstrated to be an effective solution. It has also allowed the operator to expand the use of the ESP in gassy wells, previously thought to be unsuitable for ESP application.
Downhole Fluid Conditioning System for Electric Submersible Pumps
Authors: Tarabelli Roberto , Ingouville Dolores , Rivas Olegario
Published: May 2013

Argentinian oil production comes from five basins: the Noroeste basin in northern Argentina, the Cuyana and Neuquina basins in west-central Argentina, and two southern basins, the Golfo San Jorge at the center of Patagonia and the Austral, south of Patagonia.

The Golfo San Jorge Basin is amongst the most prolific, with 39% of total oil production.

The two most commonly used artificial lift (AL) methods are electric submersible pumps (ESPs) for 4% of total production and rod pumps (RPs) for 27.5% of total production.

Most of the wells in these five producing basins are low-volume producers. Of the total wells, 80% produce less than 252 bpd (40 m3/d) and 13% produce between 252 bpd (40 m3/d) and 629 (100 m3/d). Because of these low production rates, RP systems account for the biggest percentage of AL installations in Argentina.

Because of environmental considerations, the water injection process to support reservoir pressure is under evaluation in the Golfo San Jorge basin. Well productivity in the region has decreased because water injection flow rates have been reduced. To overcome this reduction in the productivity, ESPs are being installed deeper in the wells (at or below perforation depths) allowing an increase in the drawdown of the wells that corresponds to an increase in production rate. However, setting the ESP system adjacent to or below the perforations may adversely affect the cooling efficiency of the ESP motor.

In a field trial in this basin, a recirculation system—the downhole fluid conditioning system for ESPs—was installed as a solution to the adverse motor cooling issues that typically result when ESPs are installed in front of the perforations. This recirculation system maintains or even increases the production rate by installing the ESP system deeper in the well. The system in this field study was installed in October 2007 and has a run life of more than 3 years.
Successful Strategy through Artificial Lift Systems to Develop Coalbed Methane Production in Colombia
Authors: Sarmiento Varela D. B. , Monroy Barrios M.. , Gil Chacon A.. , Luna L.. , Buitrago A..
Published: May 2013

Beam pumping system implementation as alternative of Artificial Lift System to produce the water associated to coalbed methane (CBM), was found for this specific case as the best options in performance and realiability also (production of gas and water, handling of liquid level over the pump and higher run life).

The coal extraction developed in Pribbenow and El Descanso Mines involve degassing of coal stratums and dewatering. An artifitial lift is required to ensure an effective dewatering process and accelerate the gas and water recovery. Since the start of the project of CBM (Coalbed Methane) In Pribbenow and El Descanso Mines has been installed three types of artificial lift systems: Progressive Cavity Pump (PCP), Electrosubmersible Pumping (ESP) and Reciprocating Rod Lift (RRP).

The installation of Reciprocating Rod Lift Systems began with four wells on February 2010 and currently the project has a population of eleven operative wells, and the expansion program includes the completion of eighteen additional wells by 2012 and 2013. Optimum design installed in each well is composed of: – Hydropneumatic Variable Speed pumping units which had proven been the best choice for this application due to versatility in changing production conditions and in order to have a better handle of presented gas bags.– High Stretch sucker rods that has large resistance and also presenting good performance in corrosion environments, these are centralized according to the wear evidence.– Subsurface Tubing Pumps developed for handling high volumes of water and gas and solids production.

The achieved run life with Reciprocating Rod Lift is above seven times the run life obtained with the previous artificial lift systems (PCP and ESP).

This application becomes the first successful CBM project in Colombia and has a high potential for expansion to other areas considering that preliminaries evaluations of the CBM resources of Colombia indicates that there are at least 8 regions with large CBM potential.
Successful PCP Applications in High Deviated Wells: Breaking Away the Paradigm of PCP Only for Vertical or Low Deviated Wells in Colombia
Authors: Correa Sandra , Pertuz Gustavo , Cuellar Hipatia , Moreno Luis Felipe , Salazar Jose I , Romero Jose
Published: May 2013

It highlights the good performance of various Progresive Cavity Pumping (PCP) Systems with pumps landed in ultra high deviated angles, superior than 54°, and critical dog leg severity, 3.4 - 4.5°/100ft in Dina Terciarios field. This performance goes beyond the traditional Colombian oil industry conception about PCP system, it can only be used for vertical or slightly deviated wells and there is a large prevention regarding.

This paper applies for any well with fluid properties and production conditions where PCP technically applies as an artificial lift system, and the critical well geometry rejects the PCP systems due to curvature characteristics, horizontal and highly deviated wells. This specific case is focused to Dina Terciarios as an oil field and two Operator oil companies, Petrominerales and Ecopetrol.

Five PCP Systems have successfully been working in this field since March 2010 with pumps landed at deviation angles of up to 80 degrees and 4.5°/100 ft dog leg severity.

The average Run Life for those wells is higher than 652 days, including a maximum performance in the DT-137 well of 1041 days and counting.

Technically speaking the key factors of these PCP applications are the use of continuous rod, instead of conventional sucker rods, tubing rotators in surface and an appropiate management of application (lifting and pumping capacities, speed and torque control), all oriented to minimize contact loads and wearing effect associated to the well survey and operational conditions.

For both Operator companies this new PCP scope has shown economic advantages in terms of equipment and maintenance costs, well services and spare parts, changing their technical point of view and being a reference for other areas in Colombia.
Aggressive Applications: Successful Beam Pump Systems under Ultra High GOR and Deviated Conditions in Guaduas Field - Colombia
Authors: Monroy Manuel , Urdaneta Octavio , Finol Edeberto , Estupinan Diego , Chicaiza Dario , Rodriguez Luis Fernando
Published: May 2013

Results of the optimization in Guaduas Field with the implementation of the Beam Pumping as an alternative of Artificial Lift System. Installation of different equipment and pumping units as required by the well, Long Stroke, Variable speed hydra-pneumatic and Conventional units, subsurface pump, gas separator, and sucker rod design to deviated wells, allowed increasing of oil production between 40-60%.

Guaduas is a field with an ultra-high GOR reservoir and wells highly deviated, typically the field has been produced with ESP, but the gas generated low volumetric efficiency in the pump; besides, wells near at 60 grades of inclination and DLS more than 6 grades/100 ft. The beam pumping was the method that allowed production increasing and reduction of energy cost per barrel produced.

The implementation initially was for five wells, ES-1N, ES-2E, TP-1E, ES-2S and ES-1S, during 18 months, achieving important production incremental, e.g., 520 BOPD to 1009 BFPD.

Gas production was reoriented to internal consumption and local sell processes.

Results evaluation from reciprocating rod lift systems installed opened opportunities for more additional wells and initiation of a benchmarking process regarding other lifting applications in Guaduas field.

Petroleum community knows successful applications with less uncertainty to choose the best Artificial Lift Method to produce their wells; this, increasing oil production and exploring new limits for gas production and high GOR issues associated.
Mature Fields, Oil Well Optimization Using Plunger Lift Systems in Tibu Field
Authors: Andrade Julio , Parada S. Milena , Jimenez Jose L.
Published: May 2013

For oil wells with high GLR and low potential in mature fields, the production is not only affected by the declination, but also by well backpressure coming from liquid load. This paper presents the plunger lift project results in the Tibu field, North of Santander, Colombia where it was possible to optimize the wells production, with additional reservers according to the natural well depletion curve.

For the wells that make part of the study, the predominant method production was stop cocking that consists in closing well regularly to reestablish well pressure and once the desired pressure is reached, the well is opened until the pressure and production drop. After Plunger Lift implementation, a production increasment was registered, for about 137% up.

The steady production evidenced technical and economic advantages of engineering and technology in the operation field.

Although the plunger lift system in Colombia is not frequently used, the success of Tibu field results gives another alternative to optimize production in Colombia.
Successful Installation of 7" Bypass System for PLT Test on Highly Deviated Wells in Colombia
Authors: Orozco Diego , Lopez Bladimir , Rodriguez Alfredo , Lozano Ramiro , Rincon German , Duran Jaime Alberto , Pinto F..
Published: May 2013

Oil and Gas industry use PLT methods to obtain information of the reservoir, dynamic test using ESP artificial lift systems with Bypass to allow have access to the perforations has been commonly used on 9 5/8" Casing on different weights. However not all the time those casing sizes are available raising the requirement of logging on 7" casing configuration which require slim design equipment on both ESP and By pass tools in order to leave enough clearance not only to run and pull the equipment safely but also to make it suitable for PLT logging (using Wireline and Coil tubing) when installed on hi deviated well configurationsi

The purpose of the following paper is to present a real example of a successful installation of 7" Bypass Systems with successful PLT logging experience in Rubiales Field (Pacific Rubiales - Colombia), using tools that has been installed and pulled several times to perform the operation on 25 wells introducing savings for over 1MM$ on completion equipment and providing important reservoir information to help develop the field. Also this documents aims to become a reference for logging process planning having the right considerations when installing this system on Hi deviated zones (over 60 Degrees)

Evidence explained on this paper helps to conclude that 7" Bypass System installed prove to comply with industry requirements on Hi deviation Wells (over 60 Degrees) and that not only can be run but also by Introducing right redress and inspection process the system can be re used several times (Over 12 times) saving money on completions equipment. Logging on Hi deviation Wells with 7" By pass Systems introduce an alternative for reservoir understanding, promising to have huge impact on the way fields can be developed by having PLT test on wells with these characteristics.
Successful Installation of a Dual Concentric Completion System on 9 5/8" Casing ESP-ESP Type in Colombia
Authors: Mata H.. , Aristizabal K.. , Rincon G.. , Duran J. A. , Pinto F..
Published: May 2013

The Oil and Gas industry is always looking for methods that reduce costs associated with the drilling process and, over the last decade, eliminate the environmental impact of well preparation. One new technology provides an option for oil and gas producers to achieve that goal allowing installation of two sets of electrical submersible pumps (ESP) on the same well bore but producing two sands separated by a packer.

The purpose of the following paper is to to present a real example of the successful installation of a Dual Concentric Completion System in COPA ASUR3, allowing two ESP systems to produce two different sands on the same well bore separated by a packer, and to demonstrate the economic effects of its use, reducing by 38% the costs associated with the drilling process, 14% on the total drill/completion investment and 50% on the environmental impact in COPA field (Colombia). The design and installation of the system were carried out taking into consideration Local Governmental regulations requiring both production zones remain insulated from each other.

Evidence explained on this paper helps to conclude that Dual Concentric Systems are proven to be applicable for specific fields with adequate sand distribution and fluid characteristics, also the use of Dual Concentric Systems complies with Government regulations keeping production from both zones isolated when applying the right integrity test procedure and that the use of Dual Concentric Systems significantly reduces costs and environmental impact associated with the drilling process and surface facilities configuration requirements.
Management and Best Practices of Progressive Cavity Pumps Failures Huyaparí Field, Orinoco Oil Belt
Authors: Yánez Eglier , Arredondo Hecsony , Han Micksu
Published: May 2013

According to the 2010-2011 annual statistical bulletin issued by the OPEC oil reserves in Venezuela reached 296.5 MMMBls, positioning the country with the biggest proven oil reserves worldwide. Most of these reserves are in the FPO (Orinoco Oil Belt) as part of the ambitious project PDVSA Magna Reserve.

The produced oil in the FPO is 8-10° API, high viscosity and located in shallow reservoirs so horizontal type wells are constructed to increase well productivity. The artificial lift system of choice is predominantly progressing cavity pump (PCP).

During the pumping operation conditions are generated that affect the performance and run life of the main elements of the pumps. T o manage and improve the run life a prudent field operator should implement specific methods to trace each pump component from delivery to the field until the final failure report is completed. This abstract describes the recommended steps, including; manufacturer quality assurance, installation documentation and completion diagram, operational data, and workover completion. The failure database should include all details: well information, bench test data, operating parameters such as torque, intake and discharge pressures, production data, operating days and accumulated revolutions, among others. At this point it is important to mention that this work will be specified only regarding the process of handling of pump failures without specifying actual statistical data that belongs to the joint venture Petropiar PDVSA (PDVSA 70% and Chevron 30%).

This methodology allows clearly identifying the weak point in the chain of the process regarding this artificial lift method. The use of it has documented properly the history of pump field failures and also serves as the basis for the completion of a significant destructive and non-destructive analysis of failed pumps with the different suppliers.

For the above and considering that only in the FPO are currently more than 3,000 wells with this system, it is necessary to manage a process to ensure the completion of the failure analysis of this equipment in a safe and technically reliable manner.
Lower Tertiary - A Fully Comprehensive Well Completion Design Methodology to Overcome Reservoir Challenges
Authors: Chavez Marco A , Garcia Gonzalo A , Pogoson Oje , Li Yu Lisa , Cardona Andres H , Nelson Roy N
Published: May 2013

In developing an encompassing well completion design, an integrated, comprehensive solution study was under taken for the Lower Tertiary, mainly Wilcox Formation in the Gulf of Mexico. This included Reservoir Characterization, Optimized Hydraulic 3-D Fracture Design and Modeling, Nodal Analysis and Production Forecasting and Reservoir Simulation to determine the optimum well completion requirements in terms of tubing size internal diameter, completion tools inner string and downhole control valve sizes.

Preliminary studies from the Wilcox Formation were taken into consideration and under the assumption of 3000 ft. MD gross height for the Wilcox formation, a representative LAS file containing the main curves for this formation was stretched out to have representative curves for the Gamma Ray, Resistivity, Neutron Porosity, Density, Sonic Delta Compressional and Values of Core Permeability.

The pore pressure gradient and stress gradient was defined for each of the zones selected for stimulation. The stress profile was calculated considering the Gamma Ray Index and VShale on a per foot basis for the zones selected considering the Gamma Ray Curve and the assumed input values for the Sand and Shale.

The mechanical properties were calculated from correlations for Vp and Vs utilizing the Vsh values as defined above, which in turn provided for determination of dynamic values for Young Modulus and Poisson on the same per foot basis. Additional calculations were performed to determine the static values of these same characteristics for each of the depths considered in the selected zones.

The optimum well completion configuration was determined with the evaluation of: the fracture design (optimum treatment schedule for each zone) and minimizing the pressure losses in the production tubing. Well completion reservoir simulations assisting to estimate the flow velocity during the well life. The production system was designed to do not exceed the critical erosion velocity of the downhole equipment.

This study assists in re-defining the well completion design requirements (maximum ratings) for ultra-deep water, high pressure and temperature applications.
Study of an Electrical Submersible Pump (ESP) as Flow Meter
Authors: Varón M. P. , Biazussi J. L. , Bannwart A. C. , Monte Verde W.. , Sassim N..
Published: May 2013

ESP (Electrical Submersible Pump) is one the most important artificial lift methods for oil in Brazil and worldwide. In this method, the centrifugal pump is driven by an electric motor directly coupled to the pump shaft. ESPs are commonly provided with a set of sensors that monitor the motor operation, temperature and head.

Measurement of liquid flow rate produced by each well is traditionally performed with specialized, costly instrumentation. As the motor sensor and the frequency inverter that drives the ESP provide useful information for pump monitoring and well management, the local flow rate through the ESP could also be determined from in-field calibration curves relating the flow rate with monitored data. Specifically, the head generated by the ESP and/or the electrical power consumed by the motor, which are usual performance curves describing the pump behavior, can be related to the flow rate of the fluid being produced. Appraisal of such flow rate measurement techniques should of course be based on the uncertainties propagated from each calibration curve. In this study, ESP performance curves of head and electrical power obtained at different operating conditions (including two-phase and viscous fluids) are used to determine the uncertainties in the liquid flow rate measurement from the curves. Results on the suitability of each method are discussed in the light of the API RP 11S2 standard, which establishes the best practices for ESP testing.
Alternative Deployment of an ESP System in South America
Authors: Blum Carlos , Jimenez Jackson , Pozo Lenin , Garibay Nicolas , Griffiths Neil , Constante Luis , Padilla Edison
Published: May 2013

As hydrocarbon reservoirs deplete and lose their natural energy to produce fluids to surface, Artificial Lift technologies become essential to maintain hydrocarbon production. Often Electric Submersible Pumps (ESPs) are selected as the optimum Artificial Lift method for a particular field/well but, typically run on jointed tubing, their limited ‘run lives’ require frequent heavy rig/hoist interventions to replace failed systems. This incurs significant production deferment, increased operating cost and unwelcome disruption to operations. Furthermore it often distracts the rigs/hoists from more profitable oil-generating activity.

In light of the above, there has been a persistent and continual drive to improve ESP performance and ‘run life’ but, nevertheless, any machine of electro-mechanical complexity will eventually fail, especially in the hostile downhole environment. Attention naturally turned to minimizing the impact of these inevitable ESP failures and focus shifted to ‘alternative deployment methods’ designed to eliminate the ‘turnaround’ time, production deferment and operating costs associated with heavy rig/hoist intervention.

Several ‘alternative’ ESP deployment options have been developed over the years but, for various valid reasons, none were readily embraced by the industry. Most recently a downhole electrical wet-connector technology has enabled ESPs to be ‘shuttled’ through tubing on wireline, coiled tubing, slickline or sucker rods and plugged into a downhole ‘docking station’ without the need of a rig or hoist. Although this technology has been successfully installed both onshore and offshore in Africa, Middle East and Far East, this paper reports the first successful installation in Latin America. Moreover, and more pertinently, the paper also reports on the expedient ‘rigless’ retrieval and replacement of the ESP system in response to an unexpected ESP system failure some months after initial installation. The latter substantiates the value proposition of this ‘alternative’ ESP deployment option. These operations took place in the PetroProducción Cuyabeno field, in Ecuador in September and December of 2012.
Evaluation of Standard Calibration Functions for Eight Electromagnetic Soil Moisture Sensors
Authors: Vaz Carlos M.P. , Jones Scott , Meding Mercer , Tuller Markus
Published: May 2013

An increasing number of electromagnetic (EM) sensors are deployed to measure volumetric soil water content (θ) for agricultural, ecological, and geotechnical applications. While impedance and capacitance sensors generally operate at frequencies between 20–300 MHz, time domain‐reflectometry (TDR) and‐transmissometry (TDT) function in the GHz range. In general, lower frequency sensors are less expensive but more sensitive to confounding effects of salinity, temperature, and soil textural variations. To simplify sensor application, factory‐supplied calibrations are often provided for different porous media types such as mineral, organic, and saline soils, or soilless‐substrates. The objective of the presented study was to evaluate the performance of eight commercially available EM moisture sensing systems (TDR 100, CS616, Theta Probe, Hydra Probe, SM300, Wet2, 5TE, 10HS) in seven well‐characterized and texturally varying soils using a standardized approach. The validity of factory supplied‐calibration relationships was evaluated and the influence of soil properties on the EM responses for θ measurements was observed. Results indicate that the factory‐supplied calibration relationships for groups of mineral and organic soils in general performed well, but some inconsistences were identified and suggestions for improvement are discussed. Soil‐specific calibrations from this study yielded accuracies of around 0.015 m3m−3 for 10HS, SM300, and Theta Probe, while lower accuracies of about 0.025 m3 m−3 were found for TDR100, CS616, Wet2, 5TE, and the Hydra Probe. These results are based on mineral soils having a large variation in texture, electrical conductivities below 2 dS m−1, organic matter below 10%, and specific surface areas of less than 50 m2 g−1.
Functionality and Safety of an Ultra-Congruent Rotating Platform Knee Prosthesis at 5.6 Years: More than 5- Year Follow-Up of the e.motion® UC-TKA
Authors: Chavoix Jean-Baptiste
Published: May 2013

Background:

Mobile bearing TKA prostheses were designed to minimize polyethylene wear by increasing implant conformity and reducing stresses between the articulating prosthesis components. It is the purpose of this study to assess the mid-term functionality and clinical outcome associated with a highly congruent mobile platform design, the e.motion® UC total knee prosthesis.

Material and Methods:

Functional and clinical outcomes were assessed after an average of 5.6 years (5.1 – 6.0 years) after total knee arthroplasty in 28 patients (24 women), aged 77.8±7.5 years. The Knee injury and Osteoarthritis Outcome Score (KOOS) was assessed. Secondary outcomes included the Knee Society Score (KSS), radiological evaluation of radiolucent lines and recording of adverse events.

Results:

The average KOOS subscore for the activities of daily life was 77.8 points after 5.6 years. Both the clinical and functional KSS improved at 2.4 and 5.6 years. Two patients showed radiolucent lines at 5.6 years. Adverse events over 5.6 years included 3 subluxations, 1 tilting and 1 misalignment of the patella. None of the prostheses were revised.

Conclusion:

This pilot study shows promising outcomes for the e.motion® UC prosthesis. In the small sample, the implant performed comparably to the LCS prosthesis (the gold standard). There were no loosenings or revisions observed at 5.6 years.
Intrapelvic Dislocation of a Femoral Trial Head During Primary Total Hip Arthroplasty Requiring Laparotomy for Retrieval
Authors: Citak Mustafa , Klatte Till Orla , Zahar Akos , Day Kimberly , Kendoff Daniel , Gehrke Thorsten , Dörner Arnulf , Gebauer Matthias
Published: May 2013

Background and Purpose:

Total hip arthroplasty (THA) is a safe and reliable surgical procedure. However, THA also has intra- and postoperative complications. A dreaded and frustrating intraoperative complication during total hip arthroplasty is dislocation of the femoral trial head from the neck into the pelvis.

Methods:

Here, we report on the case of a 71-year old female patient with osteoarthritis of the left hip. Total hip arthroplasty was performed in a lateral position through a standard posterior approach. During intraoperative trial reduction, the femoral trial head dissociated from the taper and dislocated into the psoas compartment. Several unsuccessful attempts, including an additional ventral approach, were made to immediately retrieve the femoral trial head.

Results and interpretation:

Postoperative a Computerized Tomography (CT) was performed to locate the trial head, a secondary explorative laparotomy was undertaken to retrieve it. The retrieval of the femoral trial head should be performed in a planned second surgical procedure to avoid possible complications during the manipulation necessary for retrieval.
Mechanical Quantification of Local Bone Quality in the Humeral Head: A Feasibility Study
Authors: Scola Alexander , Gebhard Florian , Weckbach Sebastian , Dehner Christoph , Schwyn Ronald , Fliri Ladina , Röderer Götz
Published: May 2013

Objectives:

Surgical treatment of proximal humerus fractures can be challenging due to osteoporosis. The weak bone stock makes stable implant anchorage difficult, which can result in low primary stability. Accordingly, significant failure rates, even with modern locking plates, are reported in the literature. Intraoperative knowledge of local bone quality could be helpful in improving results. This study evaluates the feasibility of local bone quality quantification using breakaway torque measurements.

Materials and Methods:

A torque measurement tool (DensiProbe™) was developed to determine local resistance to breakaway offered by the cancellous bone in the humeral head to quantify local bone quality. The tool was adapted to a standard locking plate (PHILOS, Synthes), allowing measurement in the positions of the six humeral head screws, as provided by the aiming device of the plate. Two hundred and seventy measurements were performed in 44 fresh cadaveric human humeri.

Results:

Handling of the tool was straight forward and provided reproducible results for the six different positions. The method allows discrimination between the respective positions with statistical significance, and thus provides reliable information on the local distribution of bone quality within the humeral head.

Discussion:

This study introduces a new method using breakaway torque to determine local bone quality within the humeral head in real time. Because DensiProbe is adapted to a standard locking plate, there is the potential for intraoperative application. The information provided could enable the surgeon to improve fixation of osteoporotic proximal humerus fractures.
In vitro conservation of two plant species (Prunus cerasifera Ehrh. and Rubus fruticosus L.) shoot tips by encapsulation dehydration
Authors: Ruzic Djurdjina , Vujovic Tatjana , Cerovic Radosav
Published: May 2013

In vitro grown shoot tips of cherry plum (Prunus cerasifera Ehrh.) and
blackberry ?Cacanska Bestrna? (Rubus fruticosus L.) were tested for regrowth
after cryopreservation using encapsulation dehydration method. Apical, 2-3 mm
long shoot tips, were encapsulated in alginate beads composed of 3, 5 and 10%
(w/v) alginic acid sodium salt in calcium-free liquid Murashige and Skoog
(MS) medium containing 1.0 mg l-1 benzyladenine, 0.1 mg l-1 indole-3-butyric
acid and 0.1 mg l-1 gibberellic acid. Polymerization was done in liquid MS
medium with 100 mM CaCl2 for 30 min at room temperature. Encapsulated shoot
tips were pre-treated in liquid MS medium with 0.75 or 1 M sucrose for 24 h
in growth room and dehydrated for 4 and 8 h (29% and 20% moisture content
respectively) before rapid immersion in liquid nitrogen. Upon thawing which
involved placing the cryovials in the air current of the laminar airflow
cabinet for 2 min, the beads were directly transferred to regrowth medium. In
cherry plum, osmotic dehydration in 0.75 M sucrose followed by 8-hour
desiccation gave the highest regrowth (60%) of explants encapsulated in 3%
and 5% alginate beads. However, in comparison with cherry plum, blackberry
displayed significantly lower capacity for regrowth after cryopreservation
under described experimental conditions. In this genotype, osmotic
dehydration in 1 M sucrose followed by 8-hour desiccation resulted in the
highest regrowth (16.7%) of explants encapsulated in 5% alginate beads.
Cryopreserved shoot tips of both genotypes multiplied in the three
subcultures had normal morphology and similar multiplication capacity in
comparison with non-cryopreserved shoots.