P&ID extraction for geothermal.
A geothermal plant is a wellfield, a brine-handling system and a power block, and each is drawn by a different discipline. The wellheads and gathering lines read like upstream oil and gas, the separators and reinjection pumps like a gas plant, and the flash or binary power block like any steam or organic Rankine cycle unit. Non-condensable gas, hydrogen sulfide and scaling drive most of the instrumentation that a conventional power plant does not carry.
What geothermal drawings carry.
- Wellhead sheets carry pressure and temperature on each production and injection well, downhole gauge telemetry, and the master and wing valves that read like an upstream wellhead schematic
- Flash plants separate steam from brine in one or two stages; the separators, scrubbers and demisters carry level and pressure control that sets the turbine inlet conditions
- Binary plants run an organic working fluid in a closed loop. The evaporator, preheater, turbine, condenser and feed pump are a small chemical-plant P&ID with hydrocarbon-service instrumentation
- Non-condensable gas removal, steam-jet ejectors or vacuum pumps, carries its own instruments and the hydrogen sulfide abatement scope downstream of it
- Hydrogen sulfide detection at the wellfield, the power block and the cooling tower is the plant's main gas-detection scope and often the only SIS-classified service
- Scaling and corrosion drive the material spec on brine lines and the inhibitor dosing instrumentation on the gathering system
- Enhanced and closed-loop geothermal projects add drilling-phase instrumentation and a longer commissioning period during which the drawing set is revised repeatedly
- Tag conventions follow the region: KKS on European and some Asian plants, ISA 5.1 in North America, the developer's house rule on district-heating projects
What the extraction delivers.
- I/O list per area: wellfield and gathering, separation and brine handling, power block, reinjection and cooling
- Instrument index across the wellhead, process and turbine drawing sets
- Equipment list covering wellheads, separators, scrubbers, ORC evaporators and turbines, condensers, reinjection pumps and cooling towers
- Line list with two-phase, brine and working-fluid service and the material spec for corrosive geothermal fluid
- Valve list for wellhead master and wing valves, flash-vessel level control and reinjection isolation
- Gas detection and ventilation subset for hydrogen sulfide
- Revision comparison across make-up well additions and plant expansions
Instrument tags on a geothermal drawing.
- PT-WH-P03Wellhead pressure on production well 3
- LT-SEP-1101First-stage separator brine level
- PT-NCG-1305Non-condensable gas suction pressure at the ejector
- AT-H2S-2201Hydrogen sulfide detector at the cooling tower basin
- TT-ORC-EV-3102Working-fluid temperature at the evaporator outlet
- FT-RI-4201Reinjection flow to injection well 2
Regulatory context.
- API 6A applies to wellhead equipment; geothermal wellheads are frequently specified against it
- ASME B31.1 and B31.3 govern the power and process piping respectively
- IEC 61511 applies to any SIS scope, typically hydrogen sulfide detection and turbine trips
- Occupational exposure limits for hydrogen sulfide set the gas-detection coverage on the wellfield and the power block
- Local geothermal resource and injection permits name the wellhead and reinjection monitoring the operator has to report
Which discipline reads it.
Process EngineersFlash separation, brine handling, non-condensable gas removal and the working-fluid loop.Controls EngineersWellhead telemetry, separator level control, turbine inlet conditions and reinjection flow.Mechanical EngineersCorrosive-service piping, reinjection pumps, ORC turbine and condenser scope.Commissioning and Startup EngineersWell-by-well tie-in verification, plant expansion change reports, gas-detection coverage checks.
Common questions
Do wellhead schematics read the same way as plant P&IDs?
Yes. A wellhead sheet carries the same tag balloons and line numbers as any process drawing, so the master valve, wing valve, wellhead pressure and downhole gauge come into the same register as the separator and turbine instruments.
Which register does the hydrogen sulfide detection land in?
The instrument index, filtered by service. Where the detection is SIS-classified the SIS subset carries it, so the functional-safety file and the plant I/O list are built from the same rows.
Can a flash plant and a binary bottoming cycle share one workspace?
Yes. One workspace per plant, segmented by drawing area, so the flash separators and the ORC loop are areas of one register.
Our plant is tagged in KKS. Does that change anything?
No. The tag is read as printed. KKS function and equipment codes come through unchanged and the register keeps the sheet reference for each.
Does the equipment list distinguish the cooling tower and reinjection scope?
The equipment list carries each item with its area and sheet, so the reinjection pumps and the cooling tower cells are separated by area rather than mixed into one list.
Run it on your geothermal drawings.
Upload a P&ID set and see the instruments, equipment, and lines it reads before committing to a plan.