Automated RGH Operational Sequence

1. Automated RGH Operational Sequence • Potential Gas in riser, Driller actuates MPO RGH system • RGH automated sequence is initiated by Driller (pre or post well control operations depending upon TOI and Chevron policy); • SCADA system automatically interrogates line up to ensure all required RGH flow spool and surface Buffer and RGH Manifold valves are correctly lined up to UMGS • Flow spool dual flow outlet valves open to dual return flow hoses and Buffer Manifold • PCVs on RGH Manifold full open • Upon confirmation the system is lined up correctly, the QCA closes in <3secs • Driller maintains circulation using riser booster pump injecting into LMRP, above closed SS BOP • RGH PCVs start to close/control to maintain 300psi ASBP on RGH Manifold while riser booster pump pressure stabilises. • Once riser booster pump pressure is stable, the RGH SCADA system starts to control the PCVs to maintain constant riser booster pump pressure • Gas is circulated out of the riser to the UMGS with the RGH system maintaining constant riser booster pump pressure • Riser is circulated to clear any gas • Riser secure