bluuebunny/crossref_metadata_2025 huggingface dataset:
New Single Well Standalone Gas Lift Process Facilitates Barnett Shale Fracture Treatment Flowback
Authors: Elmer William G. , Elmer Stuart J. , Elmer Thomas E.
Published: April 2009

When performing multiple fracture treatments in horizontal Barnett Shale wells, many operators choose to utilize artificial lift to remove fracture fluids rather than incur the expense of energized fluids that may not be effective. Gas lift has been a popular artificial lift method to remove fracture fluids, as it allows for high liquid flowrates and is excellent at handling flowback sand. Its disadvantage is that a source of lift gas is required to initiate gas lift, with this source typically being other nearby gas wells or a third party gas pipeline. In new exploration areas such as the Barnett, often neither are available. Operators resort to costly nitrogen membrane units to provide lift gas, but are left with questions about the net gas being produced (since returning nitrogen and produced natural gas are combined downhole then vented to the atmosphere). A new system (patent pending) has been developed that addresses gas lift's issues of initially filling the system with lift gas, as well as maintaining this gas so that additional gas is not required. Being a closed loop system, it also provides for very accurate measurement of net gas production by measuring any gas in excess of that needed for lift, and discharging the same to a flare stack. The paper will describe the major components used in this system, present a case history, and address the significant cost reductions and other benefits realized.
Batch Pumping: A New Method To Solve Downhole Liquid Holdup
Authors: Elmer William G.
Published: April 2009

The premise that high annular velocities on rod pumped gas wells can cause liquid holdup in the casing is presented. A case is then made (using conventional vertical separator sizing equations) that the annular cross-sectional area is inadequate to allow gas-liquid separation to occur, preventing fluid from falling below the turbulent perforations to the pump intake. The concept of "Batch Pumping" is presented to industry as a simple, cost effective method to solve this separation problem for any well with this liquid holdup problem.
Challenges and Solutions to Running Tools Through Older Well Completions Containing Significant Paraffin and Asphaltene Buildup
Authors: Vaucher D. , Parrish C. , Brooks R. T.
Published: April 2009

Scarcity of petroleum supply is causing an industry emphasis on recompletions as well as drilling. This paper will address recompletion efforts in older wells, those drilled before 1998.

In such wells, buildup of asphaltenes and paraffins presents a challenge that causes significant losses of rig time, production and revenue both onshore and offshore.

A particularly difficult situation arises when trying to run tools through older completions’ tubing and casing in which significant buildup is found. Though not fully predictable, the composition and causes of these buildups have already been the subject of many industry publications. This paper uses case studies from fields located in and around the Gulf of Mexico to illustrate the difficulties of using modern tools on these older well completions.

Once the failure conditions under which each job was performed are established, it is shown that everything from malfunction of the equipment to not being able to run the equipment at all can be directly attributed to the presence of accumulated substances. Conversely, it is shown that the success of a job can at least in part be attributed to having produced a "clean" well condition in an older well prior to running the job.

These experiences in the field serve as a means to suggest the use of different types of tools to account for the presence or absence of buildup, as well as how tools can be run to depth when there is buildup in the well.
A New Integrated Model To Simulate the Disturbed Zone in CHOPS: Spread and Erosion
Authors: Du Zhimin , Jiang Wei , Chen Zhaohui
Published: April 2009

Permeability enhancement [1], which is due to the sand produced from disturbed zone around wellbore, is the key mechanisms to improve the oil production rate in CHOPS. This has lead to the demand for the accurate predicting methodology to the amount of sand production. In this paper, a new integrated spread-erosion numerical model was developed, in which sand is produced from disturbed zone, and its dynamic performance depends on the spreading of wormhole which is determined by the pressure gradient between wormhole tips and reservoir. Also sand is fallen off from sand wall which is depends on the erosion parameter. Mechanisms case study shows that sanding will continue for a while even when the spread of disturbed zone is pause, as sand wall erosion is another source of sanding. Compare with wormhole lab testing data and sanding well monitoring data, sanding dynamic performance which is simulated by this new model is more reasonable and more reliable.
Study of Sanding Mechanism and a New Model to Calculate the Sanding Critical Drawdown in Loosened Sandstone
Authors: Du Zhimin , Ma Lining , Wang Xiaolu , Chen Zhaohui
Published: April 2009

Sanding is a common phenomena during gas production in S gas reservoir due to the loosen sandstone formation, furthermore, the rock inner cohesion will be weaken by the water produced from interbed water and edge water, as the result, sand production in-situ is enhanced. Drawdown controlling is the reasonable strategy to sand control. To calculate the critical drawdown, a new model, which is based on the theory and lab testing data analysis to the rock composition, physical and chemical mechanism, cohesion weaken by watering, is developed in this paper. In this model, rock cohesion is considered as a function of mud content and changing with water saturation, which is a typical performance in the loose sand gas reservoir. It is more reasonable and reliable to forecast the sanding critical drawdown by this new model compare with field sanding monitoring data.
Novel Perforating Job Design Triples Well Productivity
Authors: Ibrahim Hanaey , Balushi Sameer , Salsman Alan , Nunez Alvaro Javier , Situmorange Haposan
Published: April 2009

Well productivity is driven by establishing a clean connection through the near wellbore zone of drilling and completion induced permeability impairment commonly referred to as the "near wellbore damaged zone". This connection through the damaged zone is most often achieved by perforating with explosive shaped charges. The effectiveness of this connection is the result of perforator selection criteria and the well environment in which the perforating job is executed.

In the depleted oil field under study a typical completion is perforated using large Tubing Conveyed (TCP) guns in "shoot and pull" mode in a static underbalance environment. After shooting the well is killed to allow the TCP guns to be pulled safely and the completion run. Production from the newly perforated intervals declines quickly due to near wellbore damage caused by the kill cycle.

The challenge in this case was to identify the proper perforating gun system, conveyance method and perforating program to achieve the optimal productivity once the well is put on production. Modeling software was utilized to predict the productivity ratio (PR) for different perforating systems considering gun size, charge type, shot density, reservoir parameters and the well conditions at the time of shooting.

The perforating program was modified to perforate the well with gas lift on in a flowing condition maintaining under balance conditions after shooting to assist with cleanup. The under balance at the time of shooting was managed using a permanent down hole gauge installed in the completion string.

The first well completed using this process showed improved production of greater than 3 times what was expected when compared to similar wells in the field.

This paper will cover the job design criteria, the job execution requirements and evaluation of the results. In addition, a summary of the study leading to this work and the total cost reduction details for the completion operations is also included.

The result of this novel perforating job design has led to a new completion strategy for oil fields in Oman thus improving overall well performance.
Pressure-Drop Predictions in Tubing in the Presence of Surfactants
Authors: Soni Sandip , Kelkar Mohan , Perez Ciro
Published: April 2009

Many marginal gas wells cannot sustain production without artificial lift. For deep gas wells, one of the most feasible techniques is to use foam lift — inject surfactant in the well and create stable foam to lift the liquid to the surface. Unfortunately, no correlation is available to calculate the pressure drop under foam flow conditions. Conventional pressure drop prediction models are unable to correctly predict the pressure drop under these conditions. In this paper, a new model is developed to predict the pressure drop under foam flow conditions. By using a simple drift flux model and using some of the available literature data on foam, a foam pressure drop model was developed, and compared with 570 data points collected from many gas wells. The match between the model and the actual observations is reasonable. The model can be further improved if additional data on the foam quality, stability and the ability to entrain liquids becomes available.
Pressure Transient Analysis of a Multiple-Wells System in a Circular Cylinder Reservoir
Authors: Lu Jing , Zhu Tao , Dinh Anh , Tiab Djebbar
Published: April 2009

Currently in the oil industry, a field usually contains several wells producing from the same drainage domain, and each well will have an effect on the pressure at other wells. For an infinite-acting multiple wells system, pressure transient analysis is already done by using superposition principle.

This paper presents pressure drawdown equations of a multiple wells system in a circular cylinder reservoir with constant pressure outer boundary. The proposed equations provide fast analytical tools to evaluate the performance of multiple wells, which are located arbitrarily in a circular cylinder reservoir, and are producing at different rates. This paper examines the pressure drawdown response of a specific well located in a system of producing wells. The interference effects of nearby producing wells on the pressure drawdown response are investigated. The proposed equations are illustrated by numerical examples.

It is concluded that, for a given multiple wells system in a circular cylinder reservoir, well pattern, well spacing, skin factor, flow rates and well off-center distances have significant effects on single well pressure transient behaviour. Because the reservoir is under edge water drive, the outer boundary is at constant pressure, when producing time is sufficiently long, steady-state is definitely reached.
Delineation of Application: Physical and Economic Optimization of Fractured Gas Wells
Authors: Marongiu-Porcu Matteo , Wang Xiuli , Economides Michael J.
Published: April 2009

Hydraulic fracturing is particularly suited for natural gas wells. For low permeability reservoirs the need is obvious: it is the only means to monetize a huge number of gas wells. In addition, in recent years horizontal wells with multiple transverse fractures have emerged as the configuration of choice for many low permeability or unconventional reservoirs such as shale gas.

However, because of increasing demand in the world economy, previously stranded gas of much higher permeability is rapidly becoming target for new field developments. Fracturing, which for similar-permeability oil reservoirs may be abandoned in favor of horizontal or complex well architecture, is a must for higher permeability gas wells because of considerably enhanced turbulence effects.

But turbulence in the fracture itself creates the need for design adjustments because of substantial reduction in the effective proppant-pack permeability.

We present a physical optimization scheme for fracturing natural gas wells and extend it to the fracturing of multiple treatments in horizontal wells. The latter, because of enhanced turbulence effects in the fracture, has an upper limit of application, about 0.5 md. For higher permeability, the multiple fractured horizontal well has an unacceptable reduction in well performance, and vertical wells with fractures are indicated instead.

In this paper, physical optimization is complemented by economic optimization by comparing vertical wells with and without fractures and horizontal wells with multiple fractures in a range of permeabilities. Of importance are the geographic location (e.g., North America vs international) and the markedly different costs associated with them. For lower permeability reservoirs, economic considerations that would make multiple fractured horizontal wells attractive in e.g., North America, render them uneconomic in many other parts of the world. This, along with the physical constraint outlined above, creates a narrow range of permeability where the configuration is applicable.
Pipe Sticking Prediction and Avoidance Using Adaptive Fuzzy Logic and Neural Network Modeling
Authors: Murillo Adriana , Neuman Johanna , Samuel Robello
Published: April 2009

Differential pipe sticking has a major effect on drilling efficiency and well costs. This problem is affected by many parameters, such as drilling fluid properties and the characteristics of the mud cake that is formed while drilling. Comparatively little research has assessed the prediction of stuck pipe. Traditionally, stuck pipe problems are solved by using some standard methods and techniques after they occur, but the real key to savings and success is in the avoidance of the risks associated with the stuck pipe. If these risks are identified in advance, better solutions can be provided to reduce the associated costs. To account for all of the aspects of differential pipe sticking and anticipated nonlinear behavior of the variables involved, fuzzy logic and neural network modeling can be used as primary predictive tools. These methods are widely used in other industries and in the petroleum field, especially in reservoir and core analyses. This paper presents a study of the application of the concepts of fuzzy logic to the problem of differentially stuck pipe. These methods make it possible to estimate the risk of stuck pipe occurrence in the well planning procedure and during drilling in real time. The nonconvolutional analysis of the model is based on the constraints of different drilling variables. Discriminant function analysis and fuzzy logic were used to classify drilling and mud variables. Extensive simulations were performed. This paper presents a case study in which the fuzzy logic and neural network modelling are successfully used to estimate and predict pipe sticking.
Simulating a Hilly Terrain Pipeline Using Twophase Flow Correlations and Mechanistic Models
Authors: Yuan Hong , Zhou Desheng
Published: April 2009

In this study, commonly used two-phase flow pressure prediction correlations and mechanistic models for pipelines in petroleum industry are used to simulate fluid flow in a hilly terrain pipeline. Simulation results are evaluated against experimental data. The experimental data were obtained from a published paper.

Hilly terrain pipelines are often encountered in oil and gas transportation. During pipeline design and simulation, experimental data are usually unavailable to calibrate against correlations or mechanistic models. In this situation, it is difficult to determine which correlation or model to use in predicting pressure drop in hilly terrain pipes due to the complexity of flow, since in a hilly terrain pipeline, fluid flow can be uphill, downhill and horizontal.

Pressure, temperature and rate measurements as well as fluid properties were given for a 2.8 mile long hilly terrain pipeline with 12-inch and 16-inch diameters. Pressure drops obtained from correlations and mechanistic models were compared with pressure measurements. Correlations and mechanistic models evaluated in this study include Beggs-Brill, Dukler, Dukler- Eaton-Flanigan, Dukler-Flanigan, Eaton, Eaton-Flanigan and Xiao and Ansari mechanistic models.

The results of this study can be used as guidelines for choosing two-phase flow pressure prediction correlations and mechanistic models in designing and analyzing hilly terrain pipelines.
Estimation of the Well Skin Induced by Accumulation of the Completion Fluid Around Wellbore
Authors: Mazloom Jalal , Tosdevin Mike
Published: April 2009

To control sand production in a dry gas unconsolidated sandstone reservoir, cased-hole gravel packs were installed in several newly drilled wells. Routine flow-after-flow and build-up tests were carried-out in all the wells after completion and unexpectedly high Darcy skins were estimated from the test data for all of the wells. In order to prepare a remediation plan, it was crucial to understand the source of the skin. As the estimated Darcy well skins according to the tests conducted right after drilling and prior to the well completion were negligible it was concluded that the positive skins were created during the completion process. The accumulation of liquid in the formation around the wellbore during the completion process and nearwellbore damage of the formation were considered to be the two main causes of the observed well skins.

A remediation plan would not be required if the presence of the completion liquid had generated the skin as much of the liquid would be recovered at the surface in the course of production. The gas mobility reduction and blockage to the gas movement would be a consequence of completion fluid accumulated near the wellbore. In order to estimate the contribution of this completion fluid on the total skin, radial grid single-well models representing flow into the wells were constructed. The single-well model results indicated that the blockage to gas movement due to the presence of the completion liquid manifests itself as a low gas mobility area in the build-up well test data. The maximum skin arising from this low gas mobility around the well was significantly less than observed. Near-wellbore damage was therefore recognized as the main source of the high skin. A Hydrofluoric (HF) acid job was recommended based on this conclusion and a reasonable well skin was achieved after performing these acid jobs.
Horizontal Woodford Shale Completion Cementing Practices in the Arkoma Basin, Southeast Oklahoma: A Case History
Authors: Nelson Scott G. , Huff Curtis D.
Published: April 2009

The recent activity increase throughout the Arkoma Basin located in southeast Oklahoma is in large part attributed to the rapid expansion of horizontal drilling in the Woodford Shale unconventional gas play. Successful primary cementing of these wells requires slurry design considerations that conventional cementing operations typically do not consider. These horizontal laterals require more than an excellent bond log to make a good well. The unique aspects of the petrophysical and geological properties of naturally fractured shale must be considered in the design. Not only are the basic cementing aspects of zonal isolation and casing support essential, but consideration of future stimulation plans are necessary to prepare and implement a proper well completion program.

Cement slurry design and execution is a crucial part of any cementing operation. This is especially true for Woodford Shale wells where the unique nature of the shale and its completion methodologies place additional demands on the cement. Slurry design considerations and successful slurry formulations for the area will be discussed along with an overview of primary cementing practices to date. Operational considerations as they apply to the cementing of horizontal shale wells in the study area will be covered. Conclusions and recommended practices for optimum results will also be presented from case history data.
Transient-Pressure Analysis of a Well With an Inclined Hydraulic Fracture Using Type Curve Matching
Authors: Dinh Anh V. , Tiab Djebbar
Published: April 2009

Hydraulic fracturing is an important well stimulation technique that has been widely used in the oil and gas industry. Most of the pressure transient analysis techniques to analyze pressure responses of fractured wells are based on the assumption that the fracture is either vertical or horizontal. However, a hydraulic fracture could be inclined with a non-zero angle with respect to the vertical direction. Field studies have shown that most hydraulic fractures are never perfectly vertical. Thus, for an inclined hydraulic fracture, the vertical orientation assumption may lead to erroneous results in well test analysis especially when the inclination angle is significant. However, there are very few studies concerning pressure transient analysis of inclined hydraulic fracture and there is no applicable well test analysis procedure available for inclined fractures. For this reason, it is important to develop well test analysis procedures for this type of fracture.

The purpose of this study is to develop a technique, based on the pressure derivative concept, for interpreting pressure transient tests in wells with an inclined hydraulic fracture. Detailed analysis of unsteady-state pressure behavior of fully penetrating inclined fracture in an infinite slab reservoir was provided. Both uniform flux and infinite conductivity models were considered. The study has shown that inclined fracture pressure data exhibit similar flow regimes as for vertical fracture counterpart. Those flow regimes are linear and pseudo-radial flow for both uniform flux and infinite conductivity models. However, for infinite conductivity model, a bi-radial flow regime is also observed. In the case of high formation thickness to fracture half length ratio and high angle of inclination, both uniform flux and infinite conductivity inclined fracture model exhibit an additional flow regime called early radial flow. Both bi-radial flow and early radial flow regimes for inclined hydraulic fracture have not been mentioned in the literature before.

A type curve matching technique was developed in this study using both pressure and pressure derivative curves. This type curve matching procedures can be used to obtain the following parameters: half fracture length, inclination angle, formation permeability and the pseudo-skin factor. The results should be verified with other pressure plots such as semi-log plot of ?P vs. t and ?P vs. t1/2 plot. A set of type curves with associated data was also provided for uniform flux and infinite conductivity inclined fracture models. Detailed explanations, tables, figures and numerical examples are included in this paper.
New Model for Gas Well Loading Prediction
Authors: Zhou D. , Yuan H.
Published: April 2009

Liquid loading is a common issue for gas producers. Better predictions of liquid loading will help operators in reducing costs (less shutdowns) and improve revenue (more production).

Turner's entrained droplet model is the most popular one in predicting liquid loading in gas wells. However, there were still quite a few wells couldn't be covered even after a 20% upward adjustment in the paper of Turner et al.. Field practice also proves that the adjusted model still underestimates liquid loading sometimes. By studying the droplet model and liquid film mechanisms, the paper presents a new empirical model.

Previous models for liquid loading are independent of the liquid amount in a gas stream. Once gas velocity is higher than calculated critical velocity, no liquid loading exists. This paper points out that, in addition to gas velocity, liquid amount (liquid holdup) in a gas stream is also a major factor for liquid loading. There is a threshold value for liquid amount in a gasliquid mixture. Above the value, liquid loading may appear even the gas velocity of a well is higher than the critical velocity form Turner's droplet model. The presented model is the first model including the amount of liquids in the calculation of gas critical velocity. According to the new model, critical gas velocity is not a single value, it varies with the liquid holdup in the gas well once the holdup excesses the threshold value.

Well data from Turner et al. were employed in the paper for evaluating the new model's parameters. Data from the paper of Coleman et al. were also used for the validation of the new model. The prediction results from the new model are better than those from Turner's model, and even better than Turner's adjusted model in matching Turner's data. The new model is consistent with Coleman's data and conclusion.

The new model is simple and can be evaluated at wellhead condition. It can be easily used to predict liquid loading in gas wells.
Horizontal Well Production Logging Deployment and Measurement Techniques for US Land Shale Hydrocarbon Plays
Authors: Heddleston Duncan
Published: April 2009

Traditional US land hydrocarbon bearing shale formations are presently being drilled & produced via horizontal wells. These horizontal wells consist of numerous selectively shot stages containing as many as 15 stages spread out across 2000 ft to 5000 ft interval.

These completions have been hydraulically fractured with water or slick water & require a flowback period of the injected water prior to the wells being kicked off with gas production. Since these types of formations are far from being homogeneous, the horizontal laterals can intersect existing natural fractures or faults in the formation or an aggressive hydraulic frac could induce fractures into existing natural fractures or faults.

When producing horizontal wells the lateral section draw down of the formation water has the ability to enter the wellbore from these faults or fractures causing the well's gas production performance to drop & eventually die off.

This paper will showcase US land horizontal well Production Logging deployment techniques using coiled tubing or well tractor examples & measurement techniques by imaging wellbore liquid / gas holdup, fluid velocity & thermal changes across the lateral. These techniques are successfully being used on US land horizontal wells in shale gas plays, whereby these case histories located inflowing gas and water entries across the lateral section.

The emerging trend of drilling and completing long horizontal laterals in unconventional shale gas formations leads to novel deployment techniques and measurements in order to efficiently measure data across these producing lateral sections.
U.S. Gas Market: The New Trends
Authors: Schubarth S. K. , Bazan L. W. , Whitehead W. S. , Larry J. D.
Published: April 2009

In the early 1980's an excess supply of Natural Gas was established in the U.S. due to the Natural Gas Pricing Act (NGPA) of 1978. In our last two papers we documented how this excess supply aided in keeping Natural Gas prices low until it disappeared and the subsequent lack of supply led to higher prices. There continues to be much talk around the importation of LNG and how it will affect the U.S. Gas Market. In this paper we will examine how LNG imports have changed, the relationships between pricing and supply, the historic value of U.S. gas production and what New Trends are being established in the market. This paper should help the oil and gas developer understand the market influences that result in the price he receives for his product.
Guidelines for the Proper Application of Critical Velocity Calculations
Authors: Sutton Robert P. , Cox Stuart A. , Lea James F. , Rowlan O. Lynn
Published: April 2009

Critical velocity calculations in the form of charts or simple equations are frequently used by field personnel to evaluate a gas well's flowing conditions to determine if the well is experiencing liquid loading problems. Literature detailing the critical velocity necessary to keep a gas well unloaded suggests using the conditions at the top of the well as an evaluation point. This is convenient for personnel conducting the evaluation as wellhead pressure and temperature data are readily available. A number of situations exist where the use of the wellhead as the evaluation point can lead to erroneous conclusions. The most obvious situation occurs with a change in geometry downhole when a tapered tubing string is run in a well or when the tubing is set above the perforations. In these instances a more robust evaluation results from using conditions at the bottom of the well and the downhole tubing geometry. Other conditions exist where the use of downhole conditions provide a better evaluation point. The assumptions used in the development of the standard, simplified form of the critical velocity equations and charts may not be appropriate for downhole application. In these cases the fundamental equations must be used. The calculation of critical velocity requires knowledge of pressure, temperature, produced fluids and PVT properties. The determination of critical rate requires the same properties with the addition of pipe diameter. The required PVT properties including surface tension and density for both the gas and liquid phases are reviewed. Correlations to calculate water-gas surface tension were found to have excessive error so a new, more accurate method is presented. This paper provides recommendations when the use of a surface or downhole evaluation point is more appropriate in the determination of the minimum critical gas velocity for a well.
Performance Analysis of ESP Systems in High-GLR Wells: From Lab Experiments to Practical Field Applications
Authors: Elichev V. A. , Khabibullin R. A. , Krasnov V. A. , Litvinenko K. V. , Prado M. G.
Published: April 2009

This paper presents the results of field evaluation by Rosneft of correlations developed by the Tulsa University Artificial Lift Projects (TUALP) to predict the performance of the natural separation process and of Electrical Submersible Pumps (ESP) operating under multiphase flow conditions as well as Russian State University of Oil and Gas (RSUOG) correlations for the performance of rotary gas separators. The first two set of correlations were developed using data acquired with TUALP experimental facilities but have not been tested against field data. The correlations developed by the Russian State University were also accomplished using lab data and a field test validation was required. During the years of 2006 and 2007 Rosneft conduct several field tests with the purpose of evaluating the performance of several gas handling technologies for ESP installations. The valuable data from those tests enabled Rosneft to verify the accuracy and validity of TUALP and RSUOG correlations for natural separation efficiency, rotary gas separator efficiency and for ESP multiphase performance under real field operational conditions with real crude and natural gas. The TUALP-Marquez-Prado correlation was selected for natural separation efficiency, the correlations for rotary gas separators developed by RSUOG were used and the TUALP-Duran correlation was chosen for pump multiphase head degradation. An excellent match was obtained between the field test data and the correlations predictions with exception of the following cases: Natural separation for installations with a horizontal ESP;Multiphase flow head degradation in installations using gas handling devices.

The paper presents a brief description of field data, a review of correlations for natural separation efficiency and pump head degradation; and a comparison between the predicted and measured performance.
Determination of the Suitability of Reinforced Thermoplastic Pipe for Applications With Aromatic and Cyclo-Aliphatic Hydrocarbons
Authors: Weller B. , Conley J. , Parvez A. , Cheng Y.
Published: April 2009

Reinforced Thermoplastic Pipe (RTP) is a new technology that is reducing the cost of constructing oil and gas gathering pipelines while improving reliability. RTP combines high performing materials such as bimodal high density polyethylene with high strength reinforcing fibers in a unique construction to create a spoolable high pressure pipeline system. The compatibility of high density polyethylene in general and RTP specifically with aromatic and cyclo-aliphatic hydrocarbons was previously only understood in a qualitative manner. A test program was conducted to determine an appropriate quantitative application envelope.

The test program consisted of exposing samples of high density polyethylene to various concentrations of aromatic and cyclo-aliphatic hydrocarbons at various temperatures. After the samples were saturated, mechanical properties of the samples were tested at a variety of temperatures.

The mechanical properties of the exposed samples and unexposed samples were compared in order to determine an appropriate application envelope. It was determined that as the temperature was increased, the effect of the aromatic hydrocarbons on the mechanical properties of high density polyethylene increased dramatically. The results allowed for the determination of acceptable concentration levels of aromatic and cyclo-aliphatic hydrocarbons at a variety of temperatures.

RTP provides solutions to many challenges associated with the construction of gathering pipelines including construction cost, availability of skilled labour and limited construction timeframes. It is currently being used in wide range of gathering applications. The conveyed fluid in many gathering applications includes some level of aromatic hydrocarbons and napthenes. The results of this study provide guidelines for determining the suitability of RTP for such applications given the concentration of aromatic and cyclo-aliphatic hydrocarbons and the operating temperature.
Next Generation Cement Analyzers
Authors: Bhaidasna Ketan , LeBlanc Chris
Published: April 2009

During cementing operations, the cement is handled in both slurry and set forms. Physical parameters, such as gel strength, thickening time, and compressive strength, play a crucial role in determining the final cement mix used during cementing. Successful cementing requires knowing the relative strength development of the cement for its target environment and conditions, prior to actual pumping. Ultrasonic cement analyzers provide a non-destructive means for determining the relative strength development of a cement sample under downhole conditions. Using the development and improvement of the modern ultasonic cement analyzer as an example, this paper describes how a modular platform for instrument design can be developed and demonstrates how this type of development can be extended to other instruments.
Comparison of Magnetic Resonance Bin Distribution Permeability to Observed Production
Authors: Thibidoux Steven , Smith Charles H. , Huggins Ken , Ramakrishna Sandeep
Published: April 2009

The Granite Wash formation in Oklahoma is made up of arkosic detrital material resting on older Precambrian rocks. It can range in age from Precambrian to Middle Pennsylvanian. Formed by erosion of uplifted segments, it is generally granitic in nature; it may also include large areas of reworked carbonate. This wash presents a very difficult log interpretation problem since reservoir consistency varies greatly from well to well. Magnetic resonance image logs were added to the logging program to establish additional parameters that could be used for reservoir description. The standard Coates permeability equation and its variations were applied to estimate permeability with little correlation to production. An observation was made that T2 bin distribution data tended to mirror production rates. Attempts were made to establish an algorithm that would directly establish permeability for this formation using measured T2 data. By matching actual production rates to observed T2 distribution data, we developed an equation to estimate permeability. This case study presents the results of using T2 bin information for estimating permeability and includes several Granite Wash wells.
Production Optimization and Uncertainty Assessment in a CO2 Flooding Reservoir
Authors: Chen Shengnan , Li Heng , Yang Daoyong
Published: April 2009

The main objective of modern reservoir management is to maximize the oil recovery when a displacing agent, such as CO2, is injected to displace the residual oil in a reservoir. Such process can be controlled properly by allocating the injected fluids to the injectors and adjusting the produced fluids from the producers. Inappropriate production-injection strategy leads to early breakthrough, unstable pressure distribution, and low ultimate oil recovery. Furthermore, presence of physical and/or financial uncertainties elevates the complexity of the field production optimization. In this paper, a pragmatic technique has been developed and successfully applied to determine the optimum production-injection strategy in a CO2 flooding reservoir by incorporating well performance into reservoir simulation in the presence of both physical and financial uncertainties. More specifically, well rates of the injectors and flowing bottomhole pressures of the producers are chosen as the controlling variables. Several variable candidates are first assessed, determined and finally assigned to each well based on the inflow performance curve, multiphase flow behavior in the wellbore, and voidage balance within the reservoir. An objective function associated with both the average net present value (NPV) and the range of NPV uncertainty is then defined, while a modified genetic algorithm is utilized as optimization engine to determine the optimum production-injection strategy. In addition, multiple equal-probable reservoir models are used to account for the physical uncertainty, while prices of oil and CO2 are applied to assess and quantify the financial uncertainty. Compared to the production-injection strategies without optimization, it is shown from a field case that the optimum strategy can postpone the CO2 breakthrough time by 1.5 years, decrease the water cut by 8.4%, and increase the oil recovery and net present value by 7.8% and 6.6%, respectively.
Field Implementation Experience of Metal PCP Technology in Cuban Heavy-Oil Fields
Authors: Guerra E. , Sanchez A. , Matthews C.
Published: April 2009

Progressing cavity pumps (PCPs) have proven to be a successful and reliable artificial lift system for production of heavy oil reservoirs over the past few decades. The application of PCP technology for production of oil wells in general continues to expand rapidly due to ongoing advances in versatility, production rate and lift capacity, durability, and economy. As a result, the application envelope for PCP systems has grown substantially to the point where these systems now successfully compete in many areas that were traditionally reserved to Rod Pump and ESP technologies.

The development and implementation of a new type of PCP, namely the "all metal" (non-elastomeric) progressing cavity pump has been driven by the need to achieve significant improvements in the performance and run life of PCPs in high temperature/thermal well applications, and wells producing fluids which cause rapid chemical and/or mechanical degradation of elastomeric PCPs.

This paper describes the successful implementation and use of Metal PCP systems in a diverse range of extra heavy oil wells located along the northern coast of Cuba beginning in July 2005. This is believed to be the first major use of this technology in such a field application. The paper also compares the performance and run lives achieved with the Metal PCPs to that of elastomeric PCPs in the same application. In general, the field trial results have demonstrated that the strong resistance of Metal PCPs to chemical and mechanical degradation makes them a good alternative for the cold production of heavy and extra heavy oil with relatively high bottomhole temperatures and high aromatic, CO2 or H2S concentrations.
Laboratory Evaluation of a Relative-Permeability Modifier for Profile Modification in Injection Wells
Authors: Vasquez Julio , Eoff Larry , Dalrymple Dwyann
Published: April 2009

In the absence of profile modification, water injected into the reservoir will go into the high-permeability zones and will bypass the oil-saturated, low-permeability zones. This paper presents the laboratory evaluation of a water-soluble relative permeability modifier (RPM), a hydrophobically modified polymer that was developed initially for water control in production wells. By injecting the RPM within the high-permeability zones, injected water will be diverted into low-permeability zones to improve the sweep efficiency of the waterflooding project.

The polymer functions by adsorption onto rock surfaces and effectively reduces water flow with little or no damage to hydrocarbon flow. The treatments are extremely easy to mix and pump and require no postjob shut-in time. This RPM was evaluated in 5-ft and 10-ft sandpacks to investigate the following parameters: (a) depth of penetration, (b) diversion properties (c) injection rate, and (c) polymer concentration. High-permeability (~2000–1500 mD) and low-permeability (~250–150 mD) sandpacks were evaluated as porous media. Based on this laboratory evaluation, this RPM can effectively penetrate through a 10-ft sandpack providing permeability reduction to water throughout the length of the porous media. In addition, excellent diverting properties were observed while bullheading the treatment in sandpacks in parallel with significant permeability contrast.
Modern Internet Technologies Provide More Value than Traditional SCADA
Authors: Wallace Donald Ian
Published: April 2009

When it comes to SCADA and remote monitoring and control systems, technology has come a long way in recent years. From sensors, to communications, to software and the internet, the technology landscape has changed. By leveraging the latest technologies, it is now easier than ever before to monitor and manage production capacity and performance, equipment uptime, maintenance, and dispatch. Compared to traditional SCADA systems, which generally produce mountains of data, the latest technologies deliver information which companies can act upon. Once deployed, these systems become an integral part of an organization's operational infrastructure, producing more value than ever before with lower initial investment and quicker payback periods.

A customer case study demonstrates the value of deploying the latest in monitoring technologies. The paper explores the tangible savings and benefits that a user was able to achieve from deploying an Internet-based system to monitor and manage over 1,500 assets including compressors and engines at the site discussed.
A Conceptual Study of Dual Lift Design in Ultradeep Wells
Authors: Bennett Jacob T. , Yong Sai Kit , Chio Samuel , Zhu D.
Published: April 2009

For many years rod pumping has been a desirable artificial lift method for on-shore oil wells. Today, in addition to rod pumps, other artificial lift methods such as gas lift and electrical submersible pumps (ESP) are also available for assisting well production. While rod pumps have been proven to be one of the simplest and most economical choices, when it is not sufficient for high-rate wells, harsh-fluid production, or deep wells, operators turn to other lift methods to produce hydrocarbons to the surface. The selection of appropriate artificial lift methods revolves around many factors, including economics.

This paper presents a conceptual and feasibility study of combination of two methods of lifting for production of moderate volumes of oil from deep or ultra-deep onshore wells. It proposes to use an ESP and a sucker rod pumping unit simultaneously to lift fluids. The argument is that to lift from a deep well, with only ESP the cost and housing limitation of the wellbore may become a vital problem. Lifting the hydrocarbons to a certain depth by an ESP system, and then using the rod pump to transport the fluid to the surface may be a solution for deep and ultra deep wells. One of the critical issues in this concept is that rod pump lift is an intermittent lift, but ESP is a continuous lift. This issue has been address with the design of a chamber in between the two systems to accommodate the two lift devices and ensure continuity. This paper presents an example with detailed calculations to provide the technical support to the idea.

Even though this approach has not been applied in the field, once proven feasible, the dual lift method can bring a solution with economic value to artificial lift for ultra-deep onshore oil wells.
Evaluation of Suitable Locations for Generation Expansion in Restructured Power Systems: A Novel Concept of T-index
Authors: Dhadbanjan Thukaram , Chintamani Vyjayanthi
Published: April 2009

In developing countries, a high rate of growth in the demand for electric energy is felt, and so the addition of new generating units becomes inevitable. In deregulated power systems, private generating stations are encouraged to add new generations. Some of the factors considered while placing a new generating unit are: availability of resources, ease of transmitting power, distance from the load centre, etc. Finding the most appropriate locations for generation expansion can be done by running repeated power flows and carrying system studies like analyzing the voltage profile, voltage stability, loss analysis, etc. In this paper a new methodology is proposed which will mainly consider the existing network topology. A concept of T-index is introduced in this paper, which considers the electrical distances between generator and load nodes. This index is used for ranking the most significant new generation expansion locations and also indicates the amount of permissible generations that can be installed at these new locations. This concept facilitates for the medium and long term planning of power generation expansions within the available transmission corridors. Studies carried out on an EHV equivalent 10-bus system and IEEE 30 bus systems are presented for illustration purposes.
The impacts of superior politics on frontline employees' behavioral and psychological outcomes
Authors: Karadal Himmet , Arasli Huseyin
Published: April 2009

In this study the effect of superior politics on frontline employees' behavioral and psychological outcomes was examined using data collected from 4- and 5-star hotels in Northern Cyprus. The research hypotheses were tested using LISREL 8.54 through path analysis. The model test results
indicated that scarce resources are a significant determinant of superior politics. In addition, path analysis results showed that superior politics and scarce resources have a significant negative association with subordinate performance. The model test findings also demonstrated that superior
politics and scarce resources are negatively associated with job satisfaction. This research, however, failed to uncover a significant positive association between subordinate performance and job satisfaction. Similarly, scarce resources and subordinate performance did not have significant
associations with job commitment.
Emotional intelligence and psychological skills use among athletes
Authors: Lane Andrew M. , Thelwell Richard C. , Lowther James , Devonport Tracey J.
Published: April 2009

Relationships between self-report trait emotional intelligence and psychological skills were investigated. Male athletes (54) completed the Emotional Intelligence Scale (EIS; Schutte et al., 1998) and the Test of Performance Strategies (TOPS; Thomas, Murphy, & Hardy, 1999). Canonical
correlation results suggested psychological skills used in both competition and in practice relate to perceptions of emotional intelligence (Practice: Canonical R = .69, p < .001; Competition: Canonical R = .67, p < .01). Specifically, self-talk, imagery,
and activation in both practice and competition were associated with perceptions of the appraisal of others' emotions and the ability to regulate emotions. The direction of relationships showed that individuals reporting frequent use of psychological skills also reported stronger perceptions
of emotional intelligence. Future researchers should seek to establish the direction of relationships by investigating whether increased psychological skills use is associated with enhanced emotional intelligence or vice versa.