Saturday, August 28, 2010

NEW INNOVATIVE TECHNIQUE FOR ACCELERATED CORROSION MEASUREMENT & AUTOMATIC INHIBITOR CHEMICAL OPTOMIZATION



Traditional HPHT Autoclave designs have been enhanced by the introduction of real-time corrosion measurement instruments and probes, to accurately reproduce the multiphase flowing field conditions of operating pipelines and industrial environments.


Corrosion Measurement - Early Practices

Shear Stress Measurement- Effect of Velocity on Corrosion- Laminar Flow Studies

Corrosion Modeling- Multiphase Studies Accelerated Pipeline Integrity

Automated Inhibitor Injection (A.I.I.)- “Feedback” Chemical Pump Control

Corrosion Measurement

For many decades’ production and pipeline operators used simple corrosion coupons as an intermittent corrosion weight loss measurement. NACE, ASTM and others made exhaustive attempts to upgrade the method, Conducting Corrosion Coupon Tests in Plant Equipment, ASTM G4-84 originating (A224-39) in 1939.

Additional test methods were developed by NACE and others, as example TM01-77-96, Laboratory Testing of Metals for Resistance to Sulfide Stress Corrosion Cracking in H2S Environments. The standard addressed “the testing of metals for resistance to cracking failure under combined action of tensile stress and corrosion in aqueous environments containing Hydrogen Sulfide (H2S)”.

Shear Stress Measurement

The 1995 NACE Publication 5A195 State Of-The-Art on Controlled Flow Laboratory Corrosion Tests was a “compilation of experimental techniques intended to provide the most up to date information available at the time on evaluating the effect of velocity on corrosion”, called Shear Stress. Included in NACE #5A195 (but not limited to) were the contents:

  • Interpretation of Lab Measurements

  • Philosophy Behind Experimental Design

  • Experimental Systems

  • References

  • Appendix B Governing Equations:

  • Rotating Disk

  • Rotating Cylinder

  • Impingement Jet

  • Flow-Loop System

In 1996 NACE Publication #1D196 Laboratory Test Methods for Evaluating Oilfield Corrosion Inhibitors, coupled the above NACE #5A195 with the effects of chemical inhibitor applications under multiphase flow controlled test equipment for lab simulations.

During recent decades, ER/LPR became viable techniques adapted from lab studies and applied in the form of probes and instruments developed for long-term field studies.

Modern electronic components and high speed data acquisition evolution allowed a more rapid response corrosion rate measurement to be made in real time. The new probe/instrument system could be used to make measurements not only in electrolytic, but in non-conductive gas environments as well. The rapid response Systems have been readily accepted by the corrosion community as touted in NACE Papers 1997 #288 A Critical Comparison of Corrosion Monitoring Techniques in Industrial Applications, and later in NACE 2000 #00090 Field Trial Results of a New Rapid Corrosion Monitoring System

Automated Inhibitor Injection

Complimenting the high shear and impingement measurements, new Automated Inhibitor Injection (A.I.I.) systems are in operation since 1998 using the rapid response corrosion rate output signal to determine and control the optimum inhibitor chemical dose rate using variable flow rate inhibitor chemical injection pumps.

CONCLUSION

Cost of corrosion and its associated long terms costs can be significantly reduced with properly configured laboratory HPHT simulation systems, in combination with the newest state-of-the-art A.I.I. skid installations. The initial cost of these systems is quite small compared to the potential savings in material assets, non-productive downtime, the global environment and personnel safety.

G. W. Mazurk Sr. Vice President Cortest, Inc.

www. cortest.com


Thursday, August 26, 2010

Autoclave HPHT Cotest Kulim Kht RESEARCH-GRADE DUAL AUTOCLAVE SYSTEM



RESEARCH-GRADE DUAL AUTOCLAVE SYSTEM
Research Project:
Physical and corrosion properties of pipeline, downhole and refinery steels and alloys
Optimization of anti-corrosion chemicals inhibitor formulations and dosage rates
Cost Savings Relation of Laboratory Test Results to Field Operations:
Materials of Construction
Material’s selection decision can be greatly improved by evaluating the material’s performance at high temperature and high pressure in a laboratory autoclave. These systems are very versatile, permitting short term tests for inhibitor screening, medium term electrochemical evaluations, and very long-term exposures. From these results, informed decisions can be made to optimize cost vs. performance of materials used in pipelines, valves, fittings, pumps, pressure vessels, and heat exchangers.
Corrosion Inhibitors
Inhibitor performance can be evaluated using multiple techniques in autoclave systems. Shear stress measurements using jet impingement or rotating cylinder tests can accurately define inhibitor performance, permitting selection of proper formulations.
PURPOSE OF RESEARCH
This dual autoclave system is necessary to accelerate tests screening results and support the I0 Dynamic Multiphase Test Loop according to ASTM G170-01a, Paragraph 4, Summary of Guide, attached.
In accordance with ASTM and NACE Test Method Standards; accurately simulate the physical field operating conditions and easily screen material samples fitting NACE and ISO recommended practices.
a) Study corrosion behavior and effects of field operations and oil/gas chemicals from down hole to refinery, including seawater, oxygen, CO2/H2S (and other gases) and effect of flow on the surfaces of subject screening material’s test specimen.
b) Characterize the corrosion product films that adhere on materials.
c) Study the effectiveness of the anti-corrosion inhibitor chemicals for all environments, from down hole to pipelines, to storage and refinery field applications.
d) Understand and apply the test results of the measured corrosion behavior and corrosion resistance.
LITERATURE REVIEW
Lab test equipments will fully conform to ASTM G170-01a Standard Guide for Evaluating & Qualifying Oilfield& Refinery Inhibitors in the Laboratory
www.cortest.com


Surface Plasmon Resonance (2 Channels/exchangeable cuvette)


Surface Plasmon Resonance has been established as a powerful method to monitor label-free biomolecular interactions in liquids. However, today SPR can deliver well beyond kinetics and equilibrium constants: you can expect more from SPR with SPR Navi 200.

SPR

SPR Navi 200, the versatile SPR system for surface science. Surface molecular interactions Nanoscale film properties, Langmuir-Blodgett films.
Self-assembled monolayers, Spin and dip-coated layers, Non-dielectric films
Application notes are provided at our web site: www.bionavis.com
SPR and Nanoscale films. Physics and material sciences Bio-material films SwellingAdsorption/absorption- Membrane properties, Gas sensors

Surface Plasmon Resonance has been established as a powerful method to monitor label-free biomolecular interactions in liquids. However, today SPR can deliver well beyond kinetics and equilibrium constants: you can expect more from SPR with SPR Navi 200.With SPR Navi 200 – an incident beam of p-polarized light strikes an electrically conducting gold layer at the interface of a glass sensor (high Refractive Index) and an external medium with low RI (gas or liquid).At a given angle, due to a resonance phenomenon, light is exciting surface plasmons at the interface – resulting in a reduced intensity of the reflected light.A slight change at the interface (e.g. a change in refractive index or nanoscale film thickness) will lead to a change in SPR signal – allowing precise measurements of nanoscale film properties as well as surface molecular interactions.

BioNavis’ SPR Navi 200 System uses an increased angular scan range that produces a complete SPR curve. This increased angular range allows you to simultaneously characterize surfaces in gas and/or liquid. This also allows you to check the quality of user-defined surfaces before sample injection. This broadens the scope of your measurements.In addition to traditional biophysical interaction phenomena, you can characterize optical constants and thicknesses of nanoscale structures.

You can measure:
Surface-molecular interactions, Nanoscale film properties :
Langmuir-Blodgett films Self-assembled monolayers
Spin-and dip-coated layers Non-dielectric films
Physics and material sciences- Bio-material films:
Swelling Adsorption/absorption Membrane properties
Gas sensors:


BioNavis Ltd was established to develop, manufacture, supply and support Surface Plasmon Resonance (SPR) based instruments and sensors for research and diagnos-tics. The Company was founded in 2006 by private inves-tors and professionals with several decades experience in scientific instrumentation, to take over and further advance the SPR technology primarily developed at VTT - Technical Research Centre of Finland. Counting the previous devel-opment at VTT, there are more than 15 years of accumu-lated development history in the BioNavis SPR technology. BioNavis holds several international patents related to the SPR techniques and its applications.The mission of BioNavis is to respond customer needs by developing sensors, methods and research instruments which have clearly better features and performance as compared to competitors, but with affordable price.

The SPR instruments are mainly targeted to research of molecu-lar interactions, and are used by researchers in physical chemistry, biochemistry, pharmaceutics, biotechnology, and medical diagnostics.SPR Navi 200 has been developed in collaboration with Dr. Janusz Sadowski who has been the main driver in the research of SPR technique at VTT for over 20 years, and Dr. Ulf Jönsson, the founder and former CEO of Biacore, the company that pioneered the use of SPR spectroscopy for protein interaction analysis.BioNavis Ltd is based in Tampere – Finland – and provides worldwide distribution and local customer support via its fully trained and capable global network of distribution partners.

Application notes are provided at our web site: www.bionavis.com

Wednesday, August 25, 2010

Biophysical Characterisation


Introduction to Biophysical Characterisation
using Dual Polarisation Interferometry
Dual Polarisation Interferometry (DPI) is a highly versatile, powerful analytical technique for
biophysical characterisation of proteins and other biomolecules. It extends the typical dynamic
measurements of conventional biosensors by including an additional quantitative, sub molecular,
conformational measurement.

DPI delivers a unique perspective on biochemistry, linking conformational changes to biochemical activity at a resolution normally associated with ‘big physics’.
DPI is an interferometric technique to derive dynamic information concerning the thickness,
density and mass of the molecular layer. As well as mass-based affinity and kinetic
determinations possible with other label-free optical and acoustic biosensor technologies, DPI
additionally provides real-time data on the orientation of the surface immobilised layer and
any conformational changes involved upon binding.

Two polarisations of light are passed through the sensor which consists of an upper ‘sensing’ layer and an embedded ‘reference’ layer. The output from each of the layers then combine producing two interference patterns which are detected by a camera. As molecules bind (or change shape) on the surface of the ‘sensing’ layer, they are probed by the evanescent field from the ‘sensing’ surface. This, in turn, changes both interference patterns. As material binds, the interference pattern shifts one way.
As material is removed from the surface, the interference pattern returns.

The AnaLight® Resolver software automatically analyses both sets of data and outputs the real time changes in the thickness, density and mass of the molecular layer. All of the calculations are based on classical optics theory and have been independently validated by, amongst others, the National Physics Laboratory (NPL) in the UK.

Tuesday, August 10, 2010

Potentiostat with autoclave




The potentiostatic test is usually performed to determine resistance to pit initiation at a given potential and to simulate galvanic situations using any of Gill AC 8 12 Field Machine and manual potentiostat set to a stable potential whilst recording the current. In the study of pitting the cyclic sweep method can have problems related to sweep rate and too much pitting propagation before sweep reversal. The use of individual samples held at potentials around the suspected pitting potential will allow the correct determination of the pitting potential.

Tuesday, August 3, 2010

CONTACT ANGLE MEASUREMENT





Contact Angle: Theory
The following is a short introduction to the concepts involved in the measurement of contact angles. Included is an introduction to the techniques involved and some practical advise. For those interested in further information a list of references appears at the end of this chapter.
What is contact angle?
Contact angle ,q, is a quantitative measure of the wetting of a solid by a liquid. It is defined geometrically as the angle formed by a liquid at the three phase boundary where a liquid, gas and solid intersect

It can be seen from this figure that low values of q indicate that the liquid spreads, or wets well , while high values indicate poor wetting. If the angle
q is less than 90 the liquid is said to wet the solid. If it is greater than 90 it
is said to be non-wetting. A zero contact angle represents complete wetting.


Hysteresis: For any given solid / liquid interaction there exists a range of contact angles which may be found. The measurement of a single static contact angle to characterize the interaction is no longer thought to be adequate. The value of static contact angles are found to depend on the
recent history of the interaction. When the drop has recently expanded the angle is said to represent the ‘advanced’ contact angle. When the drop has recently contracted the angle is said to represent the ‘receded’ contact angle. These angles fall within a range with advanced angles approaching a maximum value and receded angles approaching a minimum value.
The difference between the maximum(advanced) and minimum(receded) contact angle values is called the contact angle Hysteresis. A great deal of research has gone into analysis of the significance of hysteresis. It has been used to help characterize surface heterogeneity, roughness and mobility. You are recommended to the papers listed in the reference of this section for details on experiments regarding hysteresis.
Contact angle can also be considered in terms of the thermodynamics of the materials involved. This analysis involves the interfacial free energies between the three phases and is given by:
glv cos q = gsv - gsl
where glv ,gsv and gsl refer to the interfacial energies of the liquid/vapor, solid/vapor and solid/liquid interfaces.