Water Shut-off Screening on a Chip
Select the water shut-off reagent formulation and concentration on reproducible models of a specific reservoir, by lithotype and permeability.
| Model permeability | incl. 0.5–10 mD |
|---|---|
| Recommendations | per lithotype |
| Formulations | polymer gels, crosslinkable systems, RPMs, microgels |
| Micromodels | specified permeability, digital rock replicas, zones of different conductivity |
| Program | baseline flow, injection, shut-in/crosslinking, post-flush |
| Metrics | water-conductivity reduction, RRF, injectivity, selectivity, blocking depth |
| Deliverables | formulation ranking, concentration and injection regime, plots, video |
Excess water production cuts oil rates and raises lifting, treatment and disposal costs. Rheology and bottle tests do not show how deep a reagent penetrates the pore space or whether oil-bearing zones stay permeable, and the same formulation behaves differently in rocks with different permeability and mineralogy. An overly concentrated formulation can plug the inlet area before reaching the target interval.
For each lithotype a series of reproducible chips is made with specified porosity, pore-size distribution, tortuosity and permeability. Permeability and injectivity are measured first, then polymer gels, crosslinkable systems, relative permeability modifiers and microgels are compared across a range of concentrations. Pressure, flow rate, penetration depth and reagent distribution are recorded, and shut-in is carried out at set temperature and pressure.
After treatment, permeability and flow properties are measured again, and the residual resistance factor, water-conductivity reduction and injectivity change are calculated. Optics show the injection front, local reagent build-up, bypass channels and plugging zones.
The customer receives recommended formulation, concentration, volume and injection regime for each lithotype, and only formulations with the required selectivity and stability move on to core testing. In one program, the optimal formulation was selected for several lithotypes of a tight reservoir in the 0.5–10 mD range.