bluuebunny/crossref_metadata_2025_split huggingface dataset:
Installation of Solid Expandable Tubular Systems Through Milled Casing Windows
Authors: Waddell Kevin , Schuurmans Rutmer 
Published: December 2007

Proposal
During development, the potential of solid expandable tubular technology promised to revolutionize the design, construction, and remediation of wells through conservation of hole size and maximization of pass-through and flow area. The increased use of this technology and value-based applications by major and independent operators is making this promise a reality. One installation after another, operators are realizing significant value creation in new well construction and increased production from remediated wells.
Initially, the envelope of well criteria in which solid expandable tubular systems were qualified was limited to relatively straight holes. However, the full application potential of this technology can only be realized by a continual broadening of the expandable operational envelope. Ongoing testing and actual field installations continue to reduce the limitations of using solid expandable tubular systems in candidate wells.
Currently, the performance of solid expandable tubular systems is proven for use in high-angle and horizontal wells, deepwater wells, multiple installations in the same well, situations that require a relatively long expandable casing string, various cementing scenarios, among others. One application of solid expandable tubular systems that was not qualified in the past was a sidetrack through a milled window. However, recent testing and successful field applications proves the viability of using solid expandable tubular systems in these circumstances.
This paper discusses factors that potentially threaten the reliable installation of solid expandable tubular systems through a milled casing window into a sidetrack or lateral wellbore, the steps taken to mitigate these factors, the procedures used to test and qualify the performance in this situation, and the results of surface and field testing. The current limitations of using solid expandable tubular systems in this application are also presented.
Important Aspects Related to the Influence of Water Depth on ERW
Authors: S. Rocha Luiz Alberto , Andrade Renata , Helena Lobato V. Freire 
Published: December 2007

Abstract
Over the last years, the drilling of extended reach wells (ERW) has become almost common practice in the oil industry. Although it still poses many technical challenges, successful applications such as the ones at Witch Farm, UK or in the South China Sea spurred the interest in ERW by the operators. In parallel, with the push for even further lateral displacement of wells, another technology frontier emerged for drillers: Extended reach wells in deepwater.
The majority of the extended reach wells are drilled from onshore sites to reservoirs that are situated under sensible locations like preserved nature or urbanized areas. Extended reach wells drilled from fixed platform installations in shallow water usually are aimed to reach outer parts of reservoirs that otherwise could not be developed economically. In deepwater, ERW allows the use of dry completion platforms such as TLP or SPAR. It improves flow assurance and reduces the cost of the well and the future interventions.
The paper at hand gives an overview on the effects of water depth on extended reach drilling (ERD).
Risk Based Inspection - A Valuable Approach
Authors: Santos Alfredo Dos , Al Hajri Abdul Aziz 
Published: December 2007

Abstract
Pressures on cost reductions, and tougher environmental regulations are driving an upsurge in the application of risk management approaches to optimise the utilisation of plant assets. Risk based inspection (RBI), and fitness-for-service (FFS) assessments are key risk management approaches to assist in minimising the risk of loss, and in maintaining plant availability at reduced maintenance costs.
In 1998 GASCO initiated the process of changing the traditional practice of inspection planning based only on probability of failure to the semi-probabilistic Risk Based Inspection planning method that uses a multi-disciplined team to identify the criticality of operating assets based on both the likelihood of failure, and the consequences of failure.
This paper describes the successful experience of the implementation of Risk Based Inspection at GASCO Bab and BuHasa plants, and identifies the key success factors which led to clear technical benefits and savings of over one million dollars per year.
Analysis of Gas Lift Installation Problems
Authors: Al Abdin Mazin Zain 
Published: December 2007

Abstract
GAS Lift is an important mean of artificial lift method being used for most of the producing wells of two major QGPC offshore oil fields. This was best-suited method to keep and extend the plateau production rate as much as possible. By means of a variety of field examples, this paper describes how quickly the trouble shooting action is required before gaslifting problems arise.
The proper analysis of a gas lift installation can become extremely important in determining whether or not it is performing satisfactorily. The general opinion and accepted practice in most cases have been to wait until some type of trouble develops before analyzing a gas lift installation. Preferably, the gas lift installation of each well should be analyzed while it is performing satisfactorily. Not only will this show whether or not the installation has been properly designed, but provide valuable information for future reference in the event of trouble. Where improvement appears possible, design changes may then be made with complete confidence. If this information is not obtained, and the tubing and gas lift valves are pulled because of some trouble, a change of design, including such things as valve spacing, valve pressure, and type of gas lift valve would still involve some guess work. There are many ways of analyzing gas lift installation problems. These can be divided into surface and subsurface methods. Surface observation methods include backpressure, total injected and produced gas volume as well as operating gas injection pressure and its behavior analysis.
Subsurface methods include flowing pressure/temperature survey analysis. Nodel analysis can also used as an effective tool for evaluating the gas lift valves performance.
Reservoir monitoring of the Draugen field through time-lapse seismic and it's business impact
Authors: Koster Klaas , Gabriels Pieter , Horvei Aksel 
Published: December 2007

Abstract
In a time-lapse 3D seismic (TL3D) project a ‘monitor’ seismic survey is compared to a ‘base’ survey. Ideally, the base survey is a 3D dataset acquired before production from the field started. Normally, the monitor survey is acquired after several years of production. The observed differences between the base and the monitor survey can be interpreted in terms of changes in fluid saturation and pressure.
When embarking on a seismic monitoring project it is important to keep the following questions in mind:
What field information might technically be obtained?
What impact will it have on reservoir management?
What is the optimal timing with respect to the drilling sequence and development decisions?
What is the probability of successfully obtaining that information from TL3D?
In this article we will work these questions out and illustrate them with an example.
Potential Application of Viscosified Treatments for Improved Bullhead Scale Inhibitor Placement in Long Horizontal Wells – A Theoretical and Laboratory Examination
Authors: Stalker R. , Graham G. M. , Oliphant D. , Smillie M. 
Published: December 2007

Abstract
Scale control in subsea horizontal wells is recognised as a particular technical and economic challenge, especially if effective chemical placement cannot be achieved through conventional bullhead squeeze treatments. When long horizontal or highly deviated wells produce from areas of high permeability contrast and high wellbore crossflow, coil tubing operations can often be the only manner in which effective chemical placement can be guaranteed. The costs associated with such treatments are extremely expensive and often prohibitive when compared with conventional bullhead operations. Such aspects were recognized as a particular risk for successful chemical treatments in the Draugen field, operated by Norske Shell. The Draugen field is located in the environmentally sensitive Haltenbank area of the Norwegian Continental Shelf, and produces oil from 6 horizontal (&gt;1,000 ft.) wells completed with pre-packed resin screens to achieve effective sand exclusion. A moderate barium sulphate scaling potential was anticipated following sea water breakthrough requiring squeeze treatments. In order to improve chemical placement in this field and reduce the requirement for coil tubing interventions for squeeze treatment, work was initiated to investigate the potential use of viscosified fluids to improve downhole chemical placement.
A range of viscosifying agents was selected following detailed literature review based upon the rheology that was expected to lead to improved chemical placement. This included common water control additives such as xanthan and HEC (hydroxyethylcellulose) biopolymers and formulated water in oil (WIO) or oil in water (OIW) emulsions. Various formulations were selected that would either remain stable (higher viscosity) or to break (to low viscosity) at reservoir temperature. It should be noted, however, that viscosities were selected far below those normally applied in water shut off or multi-stage chemical diversion treatments. A series of formation damage core flood experiments has been conducted using analogue cores to ensure that the various formulations were non damaging, allowing rapid recovery to pre-treatment effective oil permeability. In addition, more sophisticated core flooding equipment was designed to examine chemical placement and recovery in zones of different permeability.
In summary, this paper presents a literature review describing the properties of different viscosifying agents and their potential applicability for improving bullhead scale inhibitor squeeze treatments. Core flood studies on viscosifying agents with selected rheological properties will then be presented to demonstrate the potential advantages of such applications for improved chemical placement by bullhead application in horizontal wells.
Injection of Aquifer Water and GOSP Disposal Water into Tight Carbonate Reservoirs
Authors: Raju K. U. , Nasr-El-Din H. A. , Hilab V. V. , Siddiqui S. , Mehta S. 
Published: December 2007

Abstract
Disposal of produced water from oil fields is a major concern to oil companies for environmental and economic reasons. One way to dispose off this water is to mix it with injection water. A carbonate reservoir in Saudi Arabia produces wet oil where the salinity of the produced water is high (TDS up to 230,0 mg/L). The produced water contained dissolved gasses (H2S and CO2), and suspended solids (oil, corrosion products). GOSP disposal water has CaCO3 scaling potential. It contains 750 mg/L of H2S. The aquifer water contains 2 mg/L of iron. Iron sulfide scale forms once the disposal water is mixed with the aquifer water. The objective of this study is to assess potential formation damage that can result when the two waters are mixed and injected into the tight carbonate reservoir.
The current study included detailed analysis of field waters, determination of scaling potential of various waters, and extensive coreflood testing using reservoir cores. A unique feature of this study is that the cores were examined after the injection of the mixed waters by CT and SEM techniques.
Injection of mixed water into reservoir cores created wormholes which increased core permeability. This new finding indicates that disposal water is not always damaging. The effect of iron sulfide particles was found to be a function of the initial core permeability. Iron sulfide particles (0.25 micron) caused damage to cores with permeability &lt; 20 mD after injecting 1,000 PV of the mixed water. No damage was noted in high permeable cores (&gt; 100 mD) even after the injection of 600 PV of the same water.
The results of the study identifies various types of scale related to mixing GOSP disposal water and aquifer water, and determine conditions where these waters can be injected. Also, the study highlights an unexpected benefit from injecting H2S containing waters into carbonate reservoirs.
Scale Inhibitor Core Floods in Carbonate Cores: the Influence of pH on Phosphonate-Carbonate Interactions
Authors: Baraka-Lokmane S. , Sorbie K. S. 
Published: December 2007

Abstract
Scale inhibitor core floods were performed using outcrop Jurassic Portlandian chalk cores. The effect of pH on the phosphonate-carbonate interaction was studied by performing core floods at various fixed injected pH values (pH ∼6, 4, and 2). The scale inhibitor (SI) used in these core floods was 5000 ppm active DETPMP adjusted to the application pH for that core flood. Effluent concentrations of scale inhibitor, lithium tracer, calcium and magnesium are measured, as are the effluent pH values. This thorough set of measurements makes it possible to interpret the inhibitor/carbonate interaction mechanisms quite clearly.
Some carbonate dissolution is evident in all core floods which is quantified in our floods and, as expected, the degree of dissolution increases as pH decreases. The pH 2 core flood (C4) showed the highest carbonate dissolution to the extent that the fluid induced the formation of a worm hole through the core. Flood C3 carried out at pH 4 showed more carbonate dissolution than in floods carried out at pH 6, as well as giving high pH (~7) effluents. There is higher interaction between the injected solutions and the rock material in flood C3 (SI retention, Γ ≈ 4.5 mg/g), and an increase in permeability between the pre-treatment and post treatment stages (~13 %).
All floods were modelled using a well established methodology [1, 2]. For the high pH floods (pH 6) the SI return curves were modelled very accurately using an adsorption isotherm which appears to provide an excellent description of the SI/carbonate rock interaction. For the lower pH floods (pH 4 and 2), a reasonably good, but not perfect, match was obtained using a "pseudo-adsorption isotherm" approach. However, a more complete description of the SI /rock interaction involving the role of Ca2+ is required in order to accurately model all of the features of the phosphonate/carbonate interaction.
Understanding Inhibitor Action on Components of Erosion, Corrosion and Their Interactions in CO2-Containing Slurries
Authors: Wang C , Neville A , Ramachandran S 
Published: December 2007

Abstract
Erosion-corrosion is a complex mechanism of material degradation resulting from interactions between electrochemical and mechanical processes. The consequences of erosion-corrosion are severe with economic penalties resulting from premature failure of components, increased downtime and increased maintenance costs.
The use of carbon steel in conjunction with corrosion inhibitors in preventing erosion-corrosion has been observed as an economically viable solution for oil and gas piping systems. In order to produce highly effective corrosion inhibitors for erosion-corrosion environment, it is important to understand how inhibitors act on each of the material loss components in erosion-corrosion. Although research into corrosion inhibition has been extensively conducted, there is less published work dealing with inhibitors retarding erosion-corrosion.
This paper is to evaluate the efficiency of a corrosion inhibitor under severe liquid-solid impingement. It investigates the adsorption properties of films in addition to the inhibitor action on the components of erosion-corrosion using surface analysis techniques. The experiments have been conducted using a jet impingement rig capable of producing a jet with velocity of 20m/s in a CO2-saturated environment. An assessment of the total damage is made using gravimetric techniques and visual observation. The performance of the inhibitor in this extremely aggressive erosion-corrosion condition is discussed. This paper will identify the role that inhibitors can play in reducing damage in addition to that caused by corrosion and improving erosion-corrosion performance.
Guidelines For The Prevention, Control And Monitoring Of Preferential Weld Corrosion Of Ferritic Steels In Wet Hydrocarbon Production Systems Containing CO2
Authors: Queen David , Lee Chi-Ming , Palmer Jim , Gulbrandsen Egil 
Published: December 2007

Abstract
Preferential weldment corrosion (PWC) of carbon and low alloy steels used for pipelines and process and piping systems in CO2-containing media has been observed increasingly in recent years. In particular, PWC has been detected on weldments made by the manual metal arc (MMA) process using electrodes containing Ni or Ni plus Cu. With information available and industrial experience to 2000, the mechanisms of this corrosion phenomenon were still unclear. It was not possible to predict the preferential corrosion rate that may be experienced, the exact location of attack (i.e. weld metal or HAZ), or the effectiveness of corrosion inhibitors.
A programme of work sponsored by oil and gas operating companies, together with a UK health and safety regulator was conducted collaboratively by three international research organisations. The aim of this programme was to identify if methods of mitigation and prevention could be found in terms of a better understanding of the corrosion mechanisms, the effects of weldment microstructure and composition, including various small alloying additions, and the role of corrosion inhibitors. The results from this programme have been distilled into guidelines for the prevention or control of PWC, in carbon and low alloy steels systems transporting produced hydrocarbons with entrained water and CO2 but in the absence of H2S. The paper briefly describes the experimental approach and summarises the practical guidance derived from the project. The effects of brine conductivity, liquid film thickness, temperature, corrosion scales, and corrosion inhibition are discussed. Appropriate control of inhibition was established as the most reliable means of avoiding PWC. PWC should be considered during selection of inhibitors, since the inhibitor performance may vary between the sections of the weld, and inadequate inhibition may, in some cases, increase selective corrosion rates. Recommendations on inhibitor testing, selection and deployment to avoid PWC are given.
Comparison of Segmented Weld Corrosion Tests with Short and Long Pre-Corrosion and The Influence of Synergist in Corrosion Inhibitors
Authors: McNaughtan D. , Winning I. G. 
Published: December 2007

Abstract
A standard 1% Ni weld consumable typical of that used in the Oil industry was utilised to investigate the factors which influence the efficiency of corrosion inhibitors in preventing weld corrosion. Testing was conducted on a 5-segment weld electrode in standard brine under sweet conditions. Precorrosion times of between 2 hours to 5 days were employed to assess the affect of different levels of synergist in the inhibitor and what affect this had on corrosion inhibition. Electrochemical techniques including linear polarisation resistance, galvanic current and potential measurements were made to assess the influence of pre-corrosion time and the chemistry of the inhibitor. The results indicated that the length of pre-corrosion had a significant influence on the time required for the corrosion inhibitor to reduce corrosion. It was also concluded that the rate of inhibition could be controlled by application of the appropriate amount of synergist for a particular system.
The Impact of Inorganic Scale Deposits and Their Removal on General CO2 Corrosion Rates and Corrosion Inhibitor Performance
Authors: Stalker Robert , Graham Gordon M. , Simpson Caroline 
Published: December 2007

Abstract
The inter-relationship between scale and corrosion and their control in oil field production systems has been well documented in relation to increased localized "under deposit" corrosion and the potential for detrimental performance interferences between scale and corrosion inhibitors. The impact of various chemical interferences (impact on corrosion inhibitor performance by the presence of scale inhibitor) is routinely assessed in laboratory pre-screening tests. However, although the importance of iron carbonate scales and other passivating scales is well documented, the impact on corrosion control due to the deposition of more conventional inorganic scales and their removal is not generally assessed in detail. In addition, the presence of scaling ions in test brines can significantly impact the recorded corrosion rates in conventional electrochemical tests owing to the build up of deposits on the various electrode surfaces. Omitting the scaling ions can lead to a dramatic change in test conditions (for example much lower test pH's in CO2 saturated systems if bicarbonate ions are omitted from the test brine) therefore reducing the appropriateness of the test.
The work reported describes a range of laboratory tests conducted to assess the impact of inorganic precipitates (scales) and their removal on both inhibited and uninhibited corrosion rates. Initial work summarises the impact of the inclusion or exclusion of scaling ions from test brines on the corrosion rates recorded using conventional electrochemical laboratory techniques. Further tests are then reported which examine the impact on general corrosion rates and corrosion inhibition using partially pre-scaled samples and those in which scale deposits have been chemically removed.
In summary the presence of scale deposits can have a significant impact on the recorded corrosion rates and the performance of conventional corrosion inhibitors which may have important implications for chemical screening.