A new class of viscoelastic solutions -Triphenoxmethanes (TPM)-has been under development since early 2010 and remain a fruitful yet highly challenging research topic. The TPM's are viscoelastic at low concentrations (<0.5%w/w) and show good stability in highly saline hard brines. They have been tested in hard brines up to 25% TDS with high divalent cation concentration and show increasing performance with increasing salinity. The current lead candidate "TPM", which is also being scaled up for a first field trial, displays good performance to 75°C. Adsorption/retention measurements show quite acceptable values for the harsh conditions under study. Porous media testing has shown that the TPM's have good injectivity properties and mobilize significantly more oil than brine alone. In addition, oil displacement experiments with cores at residual oil concentration (Sor) have clearly shown that TPM mobilizes residual oil (ca.7% OOIP) without significant reduction of the IFT and with less than 1 PV injected fluid.

The suitability for use in a particular reservoir is a complex interplay of the molecular structure of the TPM, temperature and brine salinity: lowering the salinity increases the application temperature. The interrelationship of the different factors is an on-going, high priority activity of the integrated R&D team. Here we report on the relevant aspects for application in harsh environments and give an outlook for field application.

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