| name | neqsim-surf-field-layout-design |
| calculation_basis | screening |
| version | 0.1.0 |
| description | Design a screening subsea (SURF) field layout and place the host from open map, bathymetry and licence-block data: group wells into drill centres, place Xmas trees, templates, manifolds, PLEMs and riser bases, position an FPSO or fixed host, route and size every production, injection, service, umbilical and riser line, and export the result as georeferenced GeoJSON and a map. USE WHEN: a task needs a field layout designed rather than an existing one screened - deciding how many drill centres and templates are needed, where the host should sit, which flowline architecture to use (loop, single line or daisy chain), what size the flowlines and risers should be, how long the umbilicals are, or a georeferenced layout to hand to flow assurance, cost estimation or a NeqSim production-network model. |
| last_verified | 2026-08-12 |
| requires | {"python_packages":[],"java_packages":[],"env":[],"network":[]} |
SURF Field Layout Design
Use this skill to turn a well count, a reservoir footprint and a water depth into
a placed and routed subsea layout: drill centres, wells, Xmas trees, templates
and manifolds, PLEMs, riser bases, the host, and every flowline, riser and
umbilical between them — each line sized on velocity and each item carrying a
latitude and longitude so the result drops straight into a map or a GIS.
It is the design counterpart to neqsim-subsea-layout-geometry, which screens a
layout that already exists. Use this skill first to create the layout, then that
skill to screen step-outs, and neqsim-pipe-route-profile to put the routes on a
real seabed profile.
When to Use
- A concept study needs a subsea architecture before any layout drawing exists.
- The number of drill centres, templates and Xmas trees must follow from the
well count and the slots per template.
- The host has to be placed relative to the field, and the riser base with it.
- A flowline architecture must be chosen: a round-trip-piggable dual loop, one
dedicated line per drill centre, or a daisy chain.
- Flowline, riser and injection-line sizes are needed at a screening level.
- Total flowline, riser and umbilical lengths are needed for a SURF cost
estimate.
- The layout must be georeferenced — on a licence block, on a map, as GeoJSON.
- A production-network or flow-assurance model needs node positions and segment
lengths.
Do not use it for detailed routing, crossing design, on-bottom stability,
free-span, expansion, installation or mooring analysis.
Inputs
| Group | Fields |
|---|
| Identity and position | field_name, centre_latitude_deg, centre_longitude_deg, water_depth_m |
| Wells | producers, water_injectors, gas_injectors, slots_per_template, slot_spacing_m |
| Footprint | reservoir_length_km, reservoir_width_km, field_axis_bearing_deg, injector_offset_km, seabed_slope_deg |
| Host | host_type, host_offset_km, host_bearing_deg, riser_base_offset_m |
| Architecture | production_architecture (dual_loop, single_line, daisy_chain) |
| Sizing | design_liquid_rate_m3_per_s, design_water_injection_rate_m3_per_s, design_gas_injection_rate_am3_per_s, densities, target velocities |
Rates are actual volumetric rates at the flowing condition, not standard
volumes. Convert a standard rate with the formation volume factor before passing
it in, or the sizing is wrong by that factor.
Outputs
nodes — wells, Xmas trees, templates/manifolds, PLEMs, riser base and host,
each with a tag, local east/north, latitude, longitude and water depth.lines — every flowline, injection line, umbilical and riser, with its
service, type, endpoints, length and selected size.summary — drill-centre and tree counts, architecture, maximum step-out, and
total flowline, umbilical and riser lengths.to_geojson() — a WGS84 FeatureCollection of points, lines and the reservoir
outline, ready for any map or GIS.warnings and assumptions — what was assumed and what a reviewer must check.
Open Map and Sea Data
geodata registers openly licensed sources and plans read-only requests. It
never opens a connection of its own: execute returns the plan as a manifest
unless the caller supplies its own fetch adapter, so the same code runs in a
sandbox and on a connected workstation.
| Source | Use | Licence |
|---|
| EMODnet Bathymetry | seabed depth over the field, European seas | CC BY 4.0 |
| GEBCO grid | global bathymetry fallback | free, attribution required |
| NOAA ETOPO | global relief fallback | public domain |
| Sodir FactMaps | quadrants, blocks, wellbores, discoveries, fields, facilities, pipelines | NLOD |
| Sodir FactPages | wellbore coordinates and field records as tables | NLOD |
| Natural Earth | coastline for a locator map | public domain |
| Copernicus Marine, MET Norway NORA3 | wave, wind and current statistics for the host heading | CC BY 4.0 / open |
from surf_field_layout_design import plan_layout_data_package, execute, attribution_block
plan = plan_layout_data_package(west=24.0, south=73.0, east=26.0, north=74.0)
manifest = execute(plan)
manifest = execute(plan, fetch=my_read_only_get)
print(attribution_block(["emodnet_bathymetry", "sodir_factmaps"]))
Reproduce the attribution lines on any map you publish.
Norwegian blocks
quadrant_bounds("7324") returns the quadrant box, which is exact north of
62 degN: the label is the latitude of the southern edge and the longitude of the
western edge, spanning one degree by two. block_bounds("7324/8") divides that
into twelve 15-by-40-arc-minute blocks — but the numbering direction is a
documented assumption, not a calculation, and the returned dictionary says so.
Take the real position from the open Sodir wellbore layer and use the block box
only for orientation.
Engineering Method
Drill centres. Wells of each service are grouped into templates of
slots_per_template slots, and the resulting drill centres are spaced evenly
over 70 % of the reservoir length along the field axis. Water injectors are
offset down one flank and gas injectors up the other by injector_offset_km.
This is geometry, not a sweep study.
Host and riser base. The host sits host_offset_km from the field centre on
host_bearing_deg; the riser base PLEM sits riser_base_offset_m short of it on
the reverse bearing. Riser length is the straight riser-base-to-host distance
with a 25 % lazy-wave allowance.
Architecture. dual_loop runs two legs through the production drill centres
in opposite order, giving a round-trip pigging loop. single_line gives one
dedicated line per drill centre. daisy_chain runs one line through them all and
is flagged as not round-trip piggable.
Line sizing. The smallest standard nominal size whose velocity stays under
both the target velocity and the API RP 14E erosional velocity,
$$
v_e = \frac{1.22,c}{\sqrt{\rho}}
$$
with $v_e$ in m/s, $\rho$ in kg/m³ and $c = 100$ for continuous service. Inner
diameter follows a fixed diameter-to-wall ratio of 20; that is a screening
geometry, not a pressure-containment design.
Python Usage Pattern
from surf_field_layout_design import design_surf_layout, plot_layout_map
layout = design_surf_layout(
field_name="Example field",
centre_latitude_deg=73.375,
centre_longitude_deg=25.0,
water_depth_m=400.0,
producers=8,
water_injectors=6,
gas_injectors=2,
slots_per_template=4,
reservoir_length_km=6.0,
reservoir_width_km=3.1,
field_axis_bearing_deg=30.0,
host_offset_km=2.5,
host_bearing_deg=270.0,
production_architecture="dual_loop",
design_liquid_rate_m3_per_s=28500.0 / 86400.0,
design_water_injection_rate_m3_per_s=20000.0 / 86400.0,
design_gas_injection_rate_am3_per_s=0.63e6 * 0.012 / 86400.0,
)
print(layout.summary["drill_centres"], layout.summary["flowline_length_km"], "km")
plot_layout_map(layout, "layout_map.png")
open("layout.geojson", "w").write(json.dumps(layout.to_geojson()))
Handing the layout on
- Flow assurance and hydraulics. Each
Line gives the endpoints, length and
inner diameter that neqsim.process.equipment.pipeline.PipeBeggsAndBrills
needs; take the elevation profile from neqsim-pipe-route-profile or an open
bathymetry grid rather than the flat default.
- Production network. Drill centres map to a
Mixer manifold and wells to
WellFlow inflow, as in neqsim-production-network-routing.
- Cost.
flowline_length_km, umbilical_length_km, riser_length_km and
the tree, template and PLEM counts are the quantity take-off a SURF cost
estimate needs.
- Screening. Feed the node list to
neqsim-subsea-layout-geometry for
step-out and tie-back distance checks.
Validation Checklist
Common Mistakes
| Symptom | Cause | Fix |
|---|
| Flowlines come out far too small | Standard rates passed where actual rates are expected | Multiply by the formation volume factor first |
| Only one drill centre for many wells | slots_per_template left at a large value | Set the real slot count per template |
| The reservoir outline does not line up with the drill centres | field_axis_bearing_deg changed but the footprint not re-checked | The outline follows the same axis; check the footprint dimensions |
| Riser length equals the water depth | Riser configuration allowance ignored | The skill adds 25 % for a lazy wave; replace with a real riser analysis |
| Umbilical length looks short | Umbilicals are routed host-to-drill-centre in a straight line | Add a routing allowance, or route via the real corridor |
| The block box does not match the operator's map | The block numbering assumption | Take the position from the Sodir wellbore layer |
Limitations
- Screening geometry only: straight-line routes, no obstacle avoidance, no
crossings, no corridor or approach design.
- Drill-centre placement is geometric spacing, not a well-placement or sweep
optimisation.
- No on-bottom stability, free-span, expansion, buckling, installation, mooring
or riser-response analysis.
- Wall thickness follows a fixed D/t ratio and is not a pressure design.
- Line sizing is a velocity check only; no pressure-drop, slugging, erosion-rate
or thermal calculation.
- Met-ocean sources are registered but the host heading is not calculated.
- No proprietary or confidential data is used.
Related NeqSim Functionality
neqsim.process.equipment.pipeline.PipeBeggsAndBrills — flowline and riser
hydraulics on the routed segments.neqsim.process.equipment.reservoir.WellFlow — well inflow at each tree.neqsim.process.equipment.subsea.SubseaWell, SubseaTree — subsea equipment.neqsim.process.mechanicaldesign.subsea — SURF mechanical design and cost.- The NeqSim MCP
runPipeline and runFieldEconomics tools.
Related Skills
neqsim-subsea-layout-geometry — screens step-outs and tie-back distances for
the layout produced here.neqsim-pipe-route-profile — turns the routes here into an elevation profile.neqsim-bathymetry-profile-screening — processes the open bathymetry grid
this skill plans the request for.neqsim-production-network-routing — takes the drill centres and wells through
manifolds and flowlines to an arrival pressure.neqsim-step-out-screening — checks the tie-back distance and arrival pressure.neqsim-reservoir-model-builder — supplies the well count and the plateau rate.neqsim-capex-opex-screening — turns the quantity take-off into a cost.
References
