**Appendix A**

The incline was photographed under varying inlet conditions and with varying pressure difference over the incline. The photos show that a pressure difference setpoint around 2 mbar will give stable oil and water layers and a decent water buffer in the incline. The photos are shown in Figures A1–A4.


**Figure A1.** 300 L/min inlet flow and 30% water cut.



**Figure A2.** 300 L/min inlet flow and 70% water cut.



**Figure A3.** 500 L/min inlet flow and 30% water cut.


**Figure A4.** 500 L/min inlet flow and 70% water cut.
