Inorganic Scale

Our expert senior consultants can support your business with assessing the scale risk in your production system by working with you to review your field data, conduct scale prediction modelling and provide recommendations on strategies to mitigate and resolve potential risks.

Where scale inhibition via chemical deployment is desirable, we can propose appropriate test programs to determine the best chemistries for your system including best in class chemical qualifications. We provide scale formation, inhibition and dissolution studies for conventional and exotic scale species under field representative conditions. Quality results are produced and reported through our decades of experience, expertise and in our state of the art facilities.

Tests are supported by in-house analytical services to qualitatively and quantitatively characterise deposited solids. Following selection of the best performing chemicals, our laboratories offer extended services that can then ensure that the chemicals are suitable for the designed method of deployment. Effectiveness of squeeze treatments are assessed via core flood testing, downhole continuous injection application testing (DHCI), gas lift application testing and material compatibility testing.

Solutions to help you understand, mitigate and resolve scaling risks

Scale testing protocols have been established together with custom-designed equipment. This allows chemicals performance testing under field representative field application conditions, critical for today’s challenging production environments.  This includes a variety of equipment that can test a range of conditions, from simple ambient pressure type test conditions (bottle type tests), up to higher temperatures and pressures, e.g. Ultra High Pressure High Temperature (UHPHT) up to 250°C & 19,000psi. Testing of varying shear; stagnant to high shear conditions, and at a range of flow volumes (millilitres to 10’s litres per minute).

Types of scales investigated include:

  • Conventional scales (CaCO3, BaSO4, SrSO4, CaSO4, Mg(OH)2 etc)
  • Iron scales (e.g. sulfate, carbonate & sulphides)
  • Sulfide scales (e.g. zinc sulfide, lead sulfide and iron sulfide)
  • Silicates (e.g. calcium silicate, magnesium silicate and iron silicate)
  • Halites

Scaling formation and inhibition as a consequence of:

  • Self-scaling conditions
  • Mixing of incompatible waters
  • Changes in production conditions
  • (e.g. pressure drop across choke, loss of CO2 (pH increase) etc.)
  • Enhanced Oil Recovery (EOR) operations
  • H2S scavenger addition
  • Stimulations – spent acid production
  • Evaporative processes

Other:

  • Sulphate removal limits required to prevent scale

Facilities:

  • Expert consultancy
    • Field review
    • Scale prediction modelling
    • Scale risk assessment
    • Scale mitigation strategy recommendations
    • Test program and condition recommendations

Specialist high temperature visibility cells

    • Brine compatibility
    • Fluids compatibility
    • Chemical/ chemical compatibilities
    • Thermal stability testing
  • Static bottle tests
    • Conventional ambient pressure static tests
    • NACE TM0197, NACE TM0374 and bespoke field conditions
    • Available for all scales
    • Representative for longer residence time & or stagnant conditions
    • Chemical mechanism investigation – scale inhibition vs. dispersion
    • Static scale inhibitor adsorption test
    • Static scale dissolver tests
  • Dynamic tube blocking
    • Field representative high temperature and high pressure using dynamic flowing conditions testing
    • Capabilities up to 250°C and 19,000 psig
    • NACE 31105 procedures
    • Rate of scale formation can be measured by monitoring the blockage of scale form by restriction of microbore coils.
    • Scale formation and inhibition investigation to determine minimum effective dose for inhibitor qualification studies
    • Recommended for all scales
    • Chemical mechanism investigation – inhibition vs. dispersion
    • Scale inhibitor/ “other” chemical compatibility performance testing

Jet impingement

    • Highest shear/ kinetic energy type tests
    • Useful for mild scaling regimes (metastable scales)
    • Useful where low masses expected to form in laboratory timescale
    • Bulk vs deposition precipitation
    • Kinetic Studies (low SR)
    • Recommended for all scales

High pressure high temperature autoclaves

  • Up to 10,000 psig and 300°C field representative test conditions
  • Scale formation, inhibition and dissolution testing at field representative conditions
  • Static tests (Scale formation and dissolution)
  • Rotating cage tests
  • Jet impingement/ shear flowing tests
  • HT Thermal Ageing

Large Flow Pilot Rig

    • Field flow conditions and shears (up to 16 litres per minute flow)
    • Can replicate flow through field jewellery of interest
    • Testing complimented by scale prediction modelling and computational fluid dynamics
    • In house ion, residual inhibitor and ESEM/ EDX analyses

Evaporative Halite testing

In dynamic halite tests the system needs to account for the presence of water in the gas phase and the water composition. This requires knowledge of the formation water composition, the reservoir and production conditions. Then scale prediction software can be used to identify the highest risk conditions and associated water vapour pressures and used to design an analogue synthetic brine and the injection rate for the brine and deionised water to mimic the field conditions of interest.

The test starts at under saturated conditions with respect to halite and then are slowly modified become oversaturated.

Such tests demonstrate a co-relation between the in situ SR and the observation of halite deposition. This approach can then be used to validate scale prediction calculations and be used to assess the effectiveness of inhibitor chemicals under the most field realistic conditions achievable in a laboratory experiment.