High Pressure / High Temperature (HPHT)
In brief, high pressure/high temperature (HPHT) wells are defined as those where the undisturbed bottom hole temp at prospective reservoir depth or total depth is greater than 300°F or 150°C, or a well requiring pressure control equipment with a rated working pressure in excess of 10000 psi.
RCP understand that the operator needs to be able to rely on highly accurate and unambiguous information on how the well is responding, critical pressures, temperatures and flow returns are accurately monitored using a wide range of quality sensors.
Systems are generally designed starting with a BOP sensor required to measure the pressure and temperature in the blow out preventer itself, critically any HPHT systems will monitor as a minimum choke, kill and buffer tank pressures and temperatures, liquid seal integrity within the Poor Boy Degasser and mud flow return would all be utilised to offer an excellent overview of the drilling process.
Should the operator experience a kick from the well the HPHT system can automatically initiate an overboard dump sequence to divert excess fluids overboard relieving the pressure in the manifold flowlines and allowing the operator time to regain control of the well. Glycol injection may also be used in this process preventing hydrates forming, again an automatic control option if required.
Typical HPHT instrumentation provides high resolution analogue and digital indication of the following sensors:
• Mud Gas Separator (Poor boy degasser)
• U tube Pressure
• Buffer Tank Pressure
• U&L Choke Line Temperature
• BOP Temperature
• BOP Pressure
• Flowline Temperature