Barium Sulphate Inhibition in Subsea Systems - The Impact of Cold Seabed Temperatures on the Performance of Generically Different Scale Inhibitor Species

2003 ◽  
Author(s):  
N. Laing ◽  
G.M. Graham ◽  
S.J. Dyer
Keyword(s):  
Barium Sulphate ◽  
Scale Inhibitor ◽  
The Impact

The Influence of Turbulence (or Hydrodynamic Effects) on Strontium Sulphate Scale Formation and Inhibitor Performance

2014 ◽  
Author(s):  
Clare Johnston ◽  
Louise Sutherland
Keyword(s):  
Barium Sulphate ◽  
Test Methods ◽  
Standard Test ◽  
Field Application ◽  
Scale Formation ◽  
Test Method ◽  
Scale Inhibitor ◽  
Modified Method ◽  
Bottle Test ◽  
The Impact

Abstract Inorganic scale (carbonate, sulphate and sulphides) formation can be predicted from thermodynamic models and over recent years better kinetic data has improved the prediction of such scales in field conditions. However these models have not been able to predict the observed deposition where flow disturbances occur, such as at chokes, tubing joints, gas lift valves and safety valves. This can lead to unexpected failures of critical equipment such as downhole safety valves (DHSV’s), and operational issues such as failure to access the well for coiled tubing operations due to tubing restrictions. In recent years it has been recognised that the turbulence found at these locations increases the likelihood of scale formation and experiments have been able to demonstrate that increased turbulence also impacts the minimum scale inhibitor concentration required to prevent scale. One of the industry standard test methods used to screen inhibitors for sulphate scale inhibition is the static bottle test. In this paper the ‘static’ bottle test method is modified to investigate the effects of increasing levels of turbulence on the formation of strontium sulphate scale at a fixed brine composition. Using this modified method it has been possible to demonstrate the impact of varying turbulence on the performance of two common generic types of scale inhibitor (phosphonate and vinyl sulphonate co-polymer). Data on the mass of scale formed, scale morphology using SEM imaging and inhibitor efficiency will be linked to degree of turbulence and scale inhibitor functionality (nucleation inhibition vs. crystal growth retardation). This study builds on the previously published10 findings for barium sulphate which showed phosphonates were less affected by turbulent conditions by carrying out similar tests on strontium sulphate. A clear mechanistic conclusion can now be drawn for sulphate scale formation and inhibition under increasingly turbulent conditions. The findings from this study have a significant impact on the methods of screening scale inhibitors for field application that should be utilised and development of suitable inhibitors that perform better under higher shear conditions.

Pre-Production Deployed Scale Inhibition Treatments in Deep-Water, West Africa

2014 ◽  
Author(s):  
D.. Patterson ◽  
W.. Williams ◽  
M.. Jordan ◽  
R.. Douglas
Keyword(s):  
West Africa ◽  
Deep Water ◽  
Best Practice ◽  
Barium Sulphate ◽  
Scale Inhibitor ◽  
Monitoring Methods ◽  
Initial Water ◽  
Scale Inhibition ◽  
Production Wells ◽  
Scale Control

Abstract The injection of seawater into oil-bearing reservoirs in order to maintain reservoir pressure and improve secondary recovery is a well-established, mature operation. Moreover, the degree of risk posed by deposition of mineral scales (carbonate/sulphate) to the injection and production wells during such operations has been much studied. The current deep-water subsea developments offshore West Africa and Brazil have brought into sharp focus the need to manage scale in an effective way. In a deepwater West African field the relatively small number of high-cost, highly productive wells, coupled with a high barium sulphate scaling tendency upon breakthrough of injection seawater meant not only was effective scale management critical to achieve high hydrocarbon recovery, but even wells at low water cuts have proven to be at sufficient risk to require early squeeze application. To provide effective scale control in these wells at low water cuts, phosphonate-based inhibitors were applied as part of the acid perforation wash and overflush stages prior to frac packing operations. The deployment of this inhibitor proved effective in controlling barium sulphate scale formation during initial water production eliminating the need to scale squeeze the wells at low water cuts (<10% BS&W). To increase the volumes of scale inhibitor being deployed in the pre-production treatments and so extend the treatment lifetimes scale inhibitor was also added to the frac gel used to carry the frac sand. This paper outlines the selection methods for the inhibitor chemical for application in frac fluids in terms of rheology, retention/release, formation damage and presents the chemical returns profile from the 5 wells treated (some treatments lasting > 300 days) along with monitoring methods utilized to confirm scale control in the wells treated. Many similar fields are currently being developed in the Campos basin, Gulf of Mexico, and West Africa, and this paper is a good example of best-practice sharing from another oil basin.

Development of a Barium Sulphate Scale Inhibitor for Chalk Solid Loaded Conditions

2019 ◽  
Author(s):  
Erin Temple ◽  
Myles Jordan ◽  
Helen Williams ◽  
Sigrid Kjelstrup ◽  
Marija Kilibarda ◽  
...  
Keyword(s):  
Barium Sulphate ◽  
Scale Inhibitor

Correlation of Shear and Turbulence on Scale Formation and Inhibition

2014 ◽  
Author(s):  
Gordon M. Graham ◽  
Hunter Thomson ◽  
Deborah Bowering ◽  
Robert Stalker
Keyword(s):  
Jet Impingement ◽  
Flow Regimes ◽  
Test Methods ◽  
Bulk Liquid ◽  
Shear Stresses ◽  
Scale Inhibitor ◽  
Static Tests ◽  
Brine Chemistry ◽  
The Impact ◽  
Production Conditions

Abstract Current scale risk analysis focuses on thermodynamic calculations to determine the risk of scale, ignoring system kinetics and the impact of flow regimes on scale precipitation from mildly oversaturated systems. It is however recognised that flow regimes affect scale precipitation. Surface growth is influenced by mass transport and diffusion which are susceptible to shear stress and turbulence. Little work has been reported which examine these factors under conditions that can be readily tuned to match field production conditions. Scale inhibitor evaluation exercises therefore often rely on conventional low shear/static or laminar flow conditions which have been demonstrated in many papers to be largely inadequate for mildly oversaturated systems. This work addresses this concept and focuses on scale deposition and growth at metal surfaces as well as bulk (liquid phase) nucleation and growth in mildly oversaturated brines as a function of increasing shear. A series of controlled experiments have been conducted under “mildly oversaturated” conditions to examine the effect of; no shear conventional “static” tests, moderate shear mixed statics and much higher shear regimes including rotating cage and jet impingement approaches with calculated shear stresses up to 500 Pa and higher. This builds on previous work published by the authors in this area1 and further illustrates the importance of conducting tests at field representative shear conditions. Since shear and turbulence have a governing effect on the critical scaling tendency (the level of oversaturation below which brines remain stable under normal production conditions) the ability to correlate between shear and the propensity for scaling in mildly oversaturated systems is critically important in determining the risk of scale at different locations in the production stream. New test methods have been validated which allow the impact of shear and turbulence to be observed under conditions more representative of production conditions. These methodologies lead to scaling in mildly oversaturated brine systems without having to adjust brine chemistry or otherwise increase the scaling regime, i.e. by adjusting the flow regime to reproduce the shear expected at critical locations in the production system. Improved methodologies are therefore presented which allow more appropriate scale inhibitor qualification, taking into account the impact of shear and turbulence under field representative conditions. The work shows that this is critically important for mildly oversaturated conditions.

The Impact of Pre-flush Additives on Scale Squeeze Treatments - Application of Modelling and New Test Methodologies to Understand Mechanisms of Retention and Optimise Field Treatment Designs

2014 ◽  
Author(s):  
O.. Vazquez ◽  
T.. Chen ◽  
L.. Crombie ◽  
P.. Chen ◽  
S.. Heath ◽  
...  
Keyword(s):  
Computer Modelling ◽  
Scale Inhibitor ◽  
Retention Mechanisms ◽  
Test Methodology ◽  
Production Stages ◽  
Modelling Techniques ◽  
Treatment Designs ◽  
The Impact ◽  
Scale Deposition ◽  
Modelling Data

Abstract One of the most common methods to prevent scale deposition in the near wellbore area is through the application of squeeze treatments which conventionally consist of pre-flush, main treatment, overflush, shut-in and back production stages. The use of additives such as polyamino acids and polyquaternary amines has often been successfully applied as part of the pre-flush stage of squeeze treatments to improve treatment lifetimes (Chen et al., 2006, Vazquez et al., 2011, Heat et al., 2012). However, although this technology has been successful applied in the field, there is still a lack of understanding of the prevalent retention mechanisms with different scale inhibitors and also a suitable test methodology and modelling techniques to optimize field treatment designs and lifetimes. A new sand pack methodology which provides a better simulation of field squeeze treatments than traditional corefloods has been designed to provide a better understanding of the scale inhibitor retention mechanisms when polyquaternary amines are applied in pre-flush treatments. This has enabled improved treatment modelling and the impact of these additives to be understood in field treatments. The performance of the polyquaternary amine is dependent upon scale inhibitor chemistry and the mechanisms of retention are addressed for both polymeric and phosphonate scale inhibitors. The adsorption isotherms were derived and compared in the absence/presence of the polyquaternary amine using specialized software, and applied to predict squeeze lifetime in field scenarios. This paper provides an understanding on the effects of polyquaternary amines on squeeze lifetime for both phosphonate and polymeric scale inhibitors supported by the application of a newly developed test methodology and computer modelling techniques. In addition, the combination of laboratory and computer modelling data coupled with field experience and a better understanding of the retention mechanisms involved now provides the ability to improve and optimize field squeeze treatment designs with polyquaternary amine pre-flush additives.

Laboratory Evaluation and Mechanistic Understanding of the Impact of Ferric Species on Oilfield Scale Inhibitor Performance

2018 ◽  
Vol 32 (8) ◽  
pp. 8348-8357 ◽  
Author(s):  
Zhang Zhang ◽  
Ping Zhang ◽  
Zhejun Li ◽  
Amy T. Kan ◽  
Mason B. Tomson
Keyword(s):  
Laboratory Evaluation ◽  
Scale Inhibitor ◽  
Mechanistic Understanding ◽  
The Impact

The Impact of EOR Polymers on Scale Inhibitor Adsorption

2020 ◽  
Author(s):  
Alan Beteta ◽  
Katherine McIver ◽  
Oscar Vazquez ◽  
Lorraine Boak ◽  
Myles Jordan ◽  
...  
Keyword(s):  
Scale Inhibitor ◽  
The Impact
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