bluuebunny/crossref_metadata_2025_split huggingface dataset:
Treatment of Temperature and Pressure Profiles along the Wellbore to Determine Gas Rate
Authors: Barrett E.. , Abbasy I.. , Wu C.-R.. -R. , You Z.. , Bedrikovetsky P.. 
Published: May 2012

AbstractGas flow profile along the wellbore is an important piece of information for reservoir management purposes, since it provides flow contribution from each producing interval along the wellbore, which is critical for optimizing well performance and maximizing recovery of reserves. Traditional methods are expensive, particularly in high temperature wells and involve running production logsging tools (PLT's) along with flowmeters. Deployment of production logging tools into a well can be operationally difficult and typically requires flow to be suspended temporarily to allow the tools to be run in hole. This can have a negative impact on the quality of data collected, potentially making it un-representative of normal producing conditions. A simple and effective method of the gas rate prediction from temperature and pressure data is discussed in this paper. Solving the inverse problem allows determination of the flow rate and thermal conductivity of the formation by matching the gas pressure and temperature distributions with measured profiles. The results of field data treatment show good agreement with the model prediction and are consistent with flowmeter (PLT) data. Besides, the approximate estimate from direct averaging using the measured data shows good accuracy of rate and thermal conductivity prediction.
Development of New Gas Viscosity Correlations
Authors: Al-Nasser Kadhem S. , AI-Marhoun Muhammad A. 
Published: May 2012

AbstractMost of the existing correlations for estimating gas viscosity were developed in mid 60's and 70's of the last century. Limited number of data was used to develop them and their accuracies are questionable. Predicting accurate gas viscosity is extremely important in the oil and gas industry as it has a major impact on reservoir recovery, fluid flow, deliverability, and well storage.In this study, a new correlation has been introduced. This correlation is simpler, features higher accuracy, and uses fewer coefficients compared with the existing correlations. Its application covers a wider range of gas specific gravity without jeopardizing the accuracy of the correlation. Another model was built using Artificial Neural Networks, ANN in order to compare its results with those obtained from the new correlation.The existing correlations were studied and analyzed using the same, large set of measured data used for this study. Most of these correlations suffered from high errors and thus were optimized using the linear and non-linear regressions. New set of coefficients for these correlations are recalculated for which the accuracy has significantly improved. In spite of such an improvement, the new correlation and new ANN model outperform the existing correlations.
Gas Dehydration Offshore or Onshore, How, How Much and Design Tips
Authors: Salamat Reza 
Published: May 2012

Abstract
Gas dehydration is a very frequent occurrence and a critical part of gas production offshore as well as onshore and therefore all the pertinent issues such as degree of dehydration, costs, design and operating "dos and don'ts" must be very well understood by the surface engineers as well as operators and managers. In the Middle East gas dehydration is particularly critical because of high reservoir pressures and high H2S/CO2 (sour gas) content and yet billions of cubic feet of gas are dried daily for gas injection or for downstream industry. But is the practice of gas drying in Middle East technically and environmentally adequate and safe?. If the water removed is not sufficient, liquid water is formed as pressure is dropped aiding line corrosion and upon further pressure reduction hydrates will form potentially blocking the flow lines. On the other hand extraction of too much water will cost the operator dearly and with the fluctuations in oil prices, revenues should be wisely used. The governing case which determines the degree of drying is the coldest operating condition for which the process gas may be subjected which means the degree of drying is a variable itself during the reservoir life and may be relaxed (or visa versa) as the reservoir life progresses and these are discussed in detail in this paper. There are various correlations used to arrive at the degree of drying and each give different results. In the proceeding paper, a range of credible dehydration methods are summarized with special emphasis on gas dehydration by TEG method as it is widely used and the salient points especially environmental issues related to the release of BTEXs into the atmosphere and how to minimize them. Various sets of correlations for dew point determination are demonstrated with real offshore case data together with unique and valuable recommendations on the design and costs optimization as well as technical/environmental safe operation.
Performance Modeling of Degraded Compressors and Fault Diagnostics
Authors: Salamat Reza 
Published: May 2012

Abstract
The use and application of compressors cannot be overemphasized in the oil & gas industry and the continuous availability of this rotating equipment is critical for maintaining safety and production profits for both offshore and onshore applications. In parallel, a compressor will degrade in its performance due to fouling and wearing and is not able to deliver the designed performance throughout its life.
As compressors continue to perform, the speed curves shift to lower heads and throughput and performance deteriorate. Based on the fact that the magnitude of the shift is different for each speed, an innovative technique for compressor performance modeling and diagnostics has been developed. It enables the actual performance of a compressor being modeled over a wide range of speeds and related flows so that the compressor performance and its operational limits can be successfully estimated. In this approach, OEM performance data is firstly used to establish an initial compressor performance model. Then field test data for a compressor is obtained and used to adapt compressor performance model to ensure the model represent the actual performance of the compressor over a wide range of speeds. As compressors continue to work, the characteristic map of the compressors shift to new positions due to recoverable and non-recoverable degradation occur to the compressors, causing the deviation of compressor operational parameters and settings. This shift represents the degradation of the compressor and can be identified by using field test data and the compressor diagnostic model described in this paper. Several methods for compressor monitoring and fault diagnostics exist. The diagnostics based on performance analysis is one of the most effective tools where the analysis of gas path (GPA) parameters provides information on the severity of degradation. The concept of GPA Index is introduced to assess the success of the diagnostic results. The performance and diagnostic results provided by the compressor diagnostic approach offer useful information to compressor operators to uphold compressor performance and to improve maintenance schedules and avoid unexpected failures. These factors will ultimately lead to an increase in revenues and safe production.
Carbonate Matrix Acidizing with Gelled Acids: An Experiment-Based Modeling Study
Authors: Ratnakar R. R. , Kalia N.. , Balakotaiah V.. 
Published: May 2012

Abstract
In-situ gelling acids are used in carbonate reservoir stimulation to reduce the leakoff rate of the acid and to divert acid to low-permeability zones. Understanding the mechanism of flow diversion and the impact of fluid rheological properties on diversion is critical to developing good matrix stimulation designs. A literature review shows that few studies present models for stimulation with in-situ gelling acids. Specifically, there are no theoretical or empirical rheological models for gelling acids that describe the effects of pH on viscosity and hence flow diversion. The objective of this work is to develop, analyze, and validate a model to represent carbonate acidizing with gelling acids.
In this work, a semi-empirical rheological model based on experimental data for gelling acids that accounts for viscosity as a function of temperature, shear rate, and pH is presented. A two-scale continuum model is developed for non-Newtonian fluids, such as gelling acids. Using the model, the effect of rheological parameters on flow diversion is analyzed and the conditions for maximum diversion are identified. The predicted results are compared with the available experimental data and field observations. A scaling analysis is also presented that leads to a criterion for the optimum injection rate for attaining maximum stimulation for a fixed amount of acid (or a minimum in pore volumes to breakthrough (PVBT)). It is shown that the optimum injection rate for gelling acids depends strongly on rheological parameters of the acid. It is found that the presence of gel leads to more branching of wormholes and more uniform stimulation compared to Newtonian acids.
Vessel Internal Electrostatic Coalescer Technology (VIEC)
Authors: AlQahtani Ali 
Published: May 2012

Abstract
In Dukhan oil production facilities, the well output is a mixture of oil, gas and water. Gas is released naturally as pressure decreases through the stages of the process. Separating oil and water is much more difficult, especially during low temperature due to the tight emulsion caused by fluid viscosity increase in spite of the demulsifier injection experienced mainly in winter time. Water droplets are dispersed forming water-oil emulsions which can be extremely stable due to surface tension and particles attaching themselves to the water-oil interface. Typically, a multi stage separation process is employed. The first stage separation vessel is one of the largest pieces of equipment on the plant. In many cases, it is time consuming to achieve the optimum oil-water separation output and requires an injection of a large amount of chemicals (demulsifier) to improve the separation efficiency.
Applying the electro coalescence technique in the first stage of separation process increases the efficiency of the separation process. This technique has been developed and is now established. This has led to a modular device known as a Vessel Internal Electrostatic Coalescer (VIEC). The VIEC is expected to reduce such phenomena by increasing the residence time and reducing the troublesome emulsion layer in the first stage separator by due to its coalescing effect hence reduced the required injection of demulsifier. The application of electrostatic force to break oil-water emulsions and increase water droplet size is an old and proven technology. A coalescer forces small water droplets to merge and form larger and thus faster sedimenting drops. Therefore, the settling velocity of water droplets in oil not only depends on viscosity and density, but also on the droplet radius squared. If the average droplet size is doubled, separation time decreases by a factor of four. Increasing droplet size is exactly what an electrocoalescer does. This means that in many cases, such as in an existing separator, production can be increased by as much as 50%.
This paper highlights first the theory of the VIEC technology. Then moves to discuss the consequences might be faced, the main features of VIEC technology. Finally shows the results of testing the new technology at different rates of chemical injection.
Aged Assets
Authors: Howell Michael Bernard 
Published: May 2012

Abstract
The concept regarding aged assets is not about how old the assets are, it is the understanding and realization of the historical condition and how the asset has changed from installation, through operational time up to its present condition and its suitability for safe and effective operation.
Ageing assets are those which have had significant deterioration or damage that has taken place since installation / commissioning or where insufficient data is available to know the extent of its operational integrity.
Deterioration can be viewed as the visual appearance caused by environment, Breakdown of protective coating and loss of containment, through to the effects of metallurgical changes within the material and internal corrosion related issues
Assumptions can be reached that assets of a significant age automatically indicate there has been significant deterioration or damage that affects the integrity or operational usage. As such each concerned asset should be individually subjected to aged asset assessment that included understanding the factors that influence the degradation. It should be noted that the photographs included are general to the subject indicated and not referenced to one specific location.
Case Study of Chloride Stress Corrosion Cracking at Gas Recycling Plant, Qatar Petroleum, Dukhan - Theories and Practicality's
Authors: Bharathan Gopalakrishnan , Al Latifi Salem 
Published: May 2012

Abstract
Chloride stress corrosion cracking (CSCC) on austenitic stainless steel sections of the oil and gas plants has been known to cause unpredictable failures, introducing high safety risks, and causing severe damage to equipment and loss of revenue. This paper discusses three cases of CSCC at the Gas Recycling plant, Qatar Petroleum, Dukhan. The incidents have all been successfully rectified and also mitigated for the future, at a nominal cost.
The article describes the 3 cases in detail, explains the analysis conducted to determine the root cause of the failure. How evidence of CSCC was confirmed in each case and what mitigation measures were considered, how the most cost effective solution was identified and implemented. It also highlights the lessons learnt to prevent such failures, in the future.
Advanced Process Control
Authors: Al-Marri Mohd Salem 
Published: May 2012

Abstract
Qatar Petroleum implemented Advanced Process Control (APC) in a plant that designed to process condensate-rich gas to recover liquid products (NGL and condensate) for further processing and export. Process control refers to the techniques to control the variables in a process. As processing plants become more complex in order to increase efficiency, maximize production or reduce costs, advanced process control needs to be applied. This new control system can improve product yield, reduce energy consumption and increase capacity. Moreover, it can improve product quality and consistency, reduce giveaway, and improve the management of transition between plant operating modes.
APC is expected to bring many benefits to plant operation. However, the extent of the benefits will be determined by specifics of the plant and how APC is applied. An analysis of the expected benefits is therefore required before a new control system can be implemented.
This paper presents how APC was installed using four controllers in specific spots in the plant. It explains how it was installed in parallel with a new Distributed Control System (DCS) to improve control stability of the process, and improve thermodynamic efficiency of the plant by optimizing the pressure profile of the process. The study identifies significant benefits from implementing the APC in the plant, including economic advantages. The APC pushed the plant to optimum operation and this has assisted in the greater recovery of condensate and NGL. Therefore, this paper shows that the objectives of the APC have been met by reaching an increase of 0.99% in production. Also, the control stability of key process variables - manipulated variables (MVs), disturbance variables (DVs) and controlled viable (CVs) - has improved by 10-67%. In addition, the operator interactions with the plant have also been decreased significantly due to the automated DCS.
Operator Training Simulator
Authors: Mulky Amarnath Shetty , Mahajan Sachin Ashokrao 
Published: May 2012

Abstract
Qatar Petroleum operates a major oil field in Dukhan wherein produces condensate and NGL from Arab-D Cap Gas Reservoir which is processed in Gas Recycling plant Dukhan. Operator Training Simulator was introduced to drive significant benefits for the plant operation in year 2007.
The OTS objective is to impart skills for DCS operation utilizing state of the art dynamic simulator for the Arab-D process.The feature of the OTS includes that all the upset conditions in the plant can be simulated close to real plant operation.
After the implementation of OTS, the benefits achieved are as below: Competency certification program has been initiated and successfully implemented which has identified clear Qatarization plan of action for new recruitsHands on experience on OTS enabled shorter duration of on the job training period. This has helped us in overcoming the current skills shortage in the Oil & Gas industryCareer progression path has been established based on various training modules with increasing complexityAfter all the operators gone through the OTS training, majority of the issues related to start up and shutdown are eliminated. It has also helped for smooth plant operation and more productivity.The strong OTS program helps eliminate errors by even experienced operators that can lead to accidents, product loss or costly plant shutdowns.The OTS program is also being used for plant troubleshooting, engineering studies and continuous improvement.
This paper will describe in detail about the OTS project design basis, project implementation, training program and its benefits.
The conclusion is that the operator training simulator is a highly effective tool and has become an indispensable part of training program.
A New Integrated Smarter Technology Application to Enhance the Performance of Water Injectors
Authors: El-Kady Alaa A. , AL-Ghafly Abdulhadi A. , Al-Jandal Ahmed A. 
Published: May 2012

Abstract
In South Ghawar field, Saudi Arabia, horizontal water injectors have recently dominated conventional vertical wells to increase injection rates and recovery. Most injectors use treated seawater to provide an injection support for Arab D carbonate reservoir with drastic permeability variations, which prevent achieving uniform injection profile and good sweep efficiency.
This paper will discuss a new smart open hole water injection completion system that marks a new era in implementing technology application for the first time in water injection wells to optimize injection and recovery. An integrated technological system that was installed consists of a distributed temperature sensing (DTS) from total depth (TD) to surface, a Permanent Downhole Monitoring System (PDHMS) and 20 inflow control devices (ICDs) with six open hole feed through swell packers.
A fiber optic DTS was used to simulate injection profiling based on mass and heat transfer that was monitored during DTS injection and warm-back data. Moreover, DTS was utilized to optimize and pumping the acid stimulation evenly during the job. The PDHMS offers unique options for injection regimes, completion integrity, formation properties, and injection assurance effectiveness. The passive ICD system was installed with the purpose to achieve a uniform injection profile for better reservoir management.
In conclusion, applying this new integrated technology application in the world for the first time in a horizontal power water injector (PWI) provides a real-time controlled uniform injection profile, optimizes treatment fluids placement, monitors casing leaks, fluid movement behind casing and the mechanical integrity of the swell packers without a costly well intervention. This in return improved the well's deliverability and efficiency. Actual field data will be presented to validate findings and support conclusions.
Non-Iron-Based Composition for In-situ Crosslinked Gelled Acid System
Authors: Patil Prajakta , Sarda Anjali , George Shoy , Choudhary Yogesh Kumar , Kalgaonkar Rajendra 
Published: May 2012

Abstract
In-situ crosslinked gelled hydrochloric (HCl) acid systems have been extensively used in matrix acidizing and acid fracturing treatments to help achieve acid diversion. These systems also help control fluid leakoff and help retard the acid reaction to allow deeper acid penetration. Presently, in-situ crosslinked gelled acid systems are generally comprised of acrylamide-based polymers, an iron crosslinker, and a breaker chemical, in addition to other additives, with HCl acid. Many iron-based crosslinker systemscan form iron depositions, precipitation/sludge, and/or scale formation during or after the acidizing treatment when the acid spends, which can causeformation damage. In addition, thismight also lead to increased operating costsbecause of the need for sludge- and/or scale-removal treatments.
To overcome these issues, a new non-iron-based composition was developed for in-situ gelled acid systems that can work in 5 to 20% HCl acid at temperatures up to 300°F. The new composition performs identicallyto that of iron-crosslinker systems but can avoid problems associated with scale formation and precipitation. The new non-iron-based composition crosslinks the polymer in the pH range of 1.5 to 3, which helps withdiverting the next acid stage into tight or damaged zones. The gelation or crosslinking can be observed as acid reacts with a carbonate formation and the pH rises above 1.5. Further, as acid continues to spend on the formation and when the pH becomes greater than 3, the gel shows a reduction in crosslinked viscosity. This newly developed system does not require any reducing agent or breaker aid because the crosslinked gel shows a complete break with acid spending. The crosslinked-gel stability of this systemfor temperatures up to 300°F is evaluated and discussed in this paper. The effect of corrosion inhibitors, along with other additives, on this new crosslinked system is also described.
Benefits of Using Advanced Electrostatic Fields in Crude Oil Dehydrators and Desalters
Authors: Sellman Erik , Sams Gary W. , Mandewalkar S. Pavan 
Published: May 2012

Abstract
Heavy crude oils continue to be a challenge to dehydrate for the Oil & Gas Industry.
The traditional remedy to the reduced oil / water density difference, higher crude oil viscosity and often smaller water droplets due to heavy crude oil production techniques, often leads to high operating temperatures, fouling, production upsets, very large treaters and dosage of large volumes of demulsifier chemicals. This leads to both higher OPEX as well as higher CAPEX.
Other challenges include higher crude oil conductivity and increased crude oil emulsion viscosity due to higher water cuts. Typically crude oil dehydration vessels use heat, retention time and AC type electrostatic dehydration technology. The AC technology provides limited voltage gradients and is not efficient for treating conductive crude oils, leading to the use of very large vessels and power units, and the use of lower voltage gradients.