Wettability is the central variable and the hardest to measure. A water-wet rock holds water in the small pores and against grain surfaces and allows oil to be displaced relatively efficiently. An oil-wet rock holds oil against the surfaces, and waterflooding leaves substantially more behind. Most reservoirs are somewhere between, and the low salinity mechanisms all propose to shift that balance toward water-wet. Measuring wettability requires preserved or properly restored core and careful procedure, and results are sensitive to how the core was handled between the reservoir and the laboratory.

Laboratory results are more variable than the underlying physics warrants, and much of that variability is procedural. Cores that were cleaned and not properly restored do not have representative wettability. Cores aged with the wrong crude, for insufficient time or at the wrong temperature do not develop representative surface chemistry. Sequential flooding through high then low salinity in the same core carries history effects. Published results that appear to contradict each other frequently differ in these procedural details rather than in the rock and fluid behaviour.

The carbonate case is different from the sandstone case. In sandstones the effect is generally associated with reduced total salinity and with clay surfaces, which means clay content is a screening criterion. In carbonates the effect is associated with specific potential determining ions, particularly sulphate, calcium and magnesium, and with their concentrations relative to each other rather than with total salinity. Seawater with modified sulphate content has produced responses in chalk and limestone that low salinity water alone does not.

Finally, field response has been more modest and more variable than laboratory results suggested. Some field trials have produced clear incremental recovery, others have produced responses within the noise of normal production variability, and interpreting which is which requires surveillance designed for the purpose. This does not mean the effect is absent; it means that screening, laboratory work and pilot design carry more weight here than for established methods.

By the end of this training, participants will be able to:

• Explain wettability, its measurement and its control on residual oil saturation
• Describe the proposed low salinity mechanisms and assess the evidence supporting each
• Screen sandstone reservoirs for low salinity potential against clay, brine and crude criteria
• Screen carbonate reservoirs for ion-modified water flooding
• Specify laboratory core flood protocols including restoration, ageing and flooding sequence
• Recognise the procedural factors that make core flood results unreliable
• Design ion tuning strategies for carbonate systems
• Represent wettability alteration in reservoir simulation
• Design pilots and surveillance capable of detecting a modest incremental response
• Specify water treatment infrastructure and assess project economics

The training develops wettability and the proposed mechanisms against experimental evidence, examining both supporting and contradicting studies so that participants can assess claims critically. Core flood protocols are worked through in detail with attention to the procedural factors that determine result reliability. Screening is applied to real reservoirs. Simulation representation approaches are compared. Reported field trials are examined for their design, their surveillance and whether their conclusions are supported by the data presented, including trials whose results remain contested.

Organisations sending participants to this training will:

• Screen reservoirs for low salinity potential on informed criteria rather than on general interest
• Commission laboratory programmes whose results will be reliable
• Design pilots capable of detecting the modest responses this method produces
• Avoid investment in water treatment infrastructure without adequate technical support
• Assess vendor and consultant claims about low salinity potential critically
• Understand how low salinity interacts with existing waterflood and injection water sourcing

Participants will:

• Understand wettability and its role in residual oil
• Assess the mechanism evidence rather than accepting a single explanation
• Specify laboratory work whose results can be trusted
• Screen reservoirs for sandstone and carbonate applications
• Design pilots and surveillance for a subtle response
• Evaluate a technology whose status remains genuinely unsettled

• Reservoir engineers evaluating improved recovery options
• Production chemists and laboratory specialists
• Development engineers working on mature waterflooded fields
• Simulation engineers modelling wettability effects
• Facilities engineers assessing water treatment requirements
• Technical staff evaluating low salinity proposals
• Petrophysicists working on wettability and saturation

Upon successful completion of this training course, delegates will be awarded an official Certificate of Completion issued by the Petroleum Engineers Association (PEA), an ISO 9001:2015 certified training organization. The certificate carries 10 Credits and formally records the total learning hours completed.

Each certificate is signed by the Course Facilitator and the CEO of the Petroleum Engineers Association, and serves as verifiable proof of professional training that delegates can present to employers and professional bodies worldwide.