Anatomy of a Well / interactive
A conduit between reservoir and surface

Build a well, one barrier at a time.

A production well is a drilled, cased and cemented path from a reservoir 1–5 km down to a valve at surface — engineered to hold pressure for 20 to 40 years. Scroll through its life and watch the schematic assemble itself: rock, steel, cement, completion, flow.

Design & construct Complete Service Abandon
Start with an empty hole — scroll to drill it

01 — Shapes & roles

The path follows the reservoir

Before any steel goes in the ground, the trajectory is chosen to expose the most pay for the fewest wells. Switch the path and see how the target changes.

Vertical

Straight down to the target. The simplest and cheapest well to drill — used where the reservoir sits directly below the location.

Producers — bring oil & gas up
Injectors — put water or gas back in to hold pressure
RESERVOIR SURFACE
02 — Design, construct & complete

Designed bottom-up, drilled top-down

The reservoir sets the target; every string above it is sized to reach it safely. Scroll each stage on the right — the schematic on the left assembles in step. Then use the controls to explore.

Well schematic — cross-section TD 3,500 m
0 m 500 1000 2000 3000 TD Freshwater aquifer High-pressure zone PAY ZONE cement top ▲ over shoe bare wellbore DHSV packer tree control line Z1Z2Z3 primary barrier plug across the reservoir secondary barrier plug independent, above reservoir surface plug shallow environmental barrier casing cut · wellhead / tree recovered wireline tool coiled tubing BOP derrick to facility wireline unit lubricator injector head reel high-pressure pumping pump trucks sea surface mudline / seabed semisub marine riser subsea BOP host FPSO jumper manifold flowline umbilical subsea tree (XT) ROV LWI vessel workover riser
Environment
Barrier envelope
Reservoir connection
Service the well
Downhole control
End of life
Casing programme4 strings
Each string is set deeper and narrower, then cemented in place. Tap a casing name in the steps to inspect it, or use the controls above.
AInputs → design

Start at the reservoir

From depth, pressure and fluid to a casing design

  • Know the target: reservoir depth, pressure, temperature and fluid type.
  • Map the hazards: unstable shales, freshwater aquifers, loss zones and sour gas.
  • Set the outputs: trajectory, total depth, and how many casing strings it takes to get there safely.
↑ The schematic shows the rock column and the pay zone at the bottom — the hole is still empty.
⇄ Switch Environment to Subsea at any point — the tree moves to the seabed and the well ties back through a jumper, manifold, flowline and riser to a host.
BCasing programme

Telescoping steel to the pay

Each string set deeper and narrower than the last

  • Conductor — supports the wellhead, stops shallow washout. Tap to inspect →
  • Surface — isolates and protects freshwater aquifers.
  • Intermediate — seals off unstable or high-pressure formations.
  • Production — confines reservoir fluids to the flow path.
↑ Tap any string to read its size, setting depth and job.
CConstruct

Drill, case, cement — repeat

Bonded to the rock, section by section, top-down

  • Drill a section: the bit cuts while mud cools it, lifts cuttings and holds back formation pressure.
  • Case & cement: run the string and pump cement into the annulus to bond steel to rock.
  • Install the BOP, then drill the next, narrower section and repeat to total depth.
Detail worth seeing Surface cement runs all the way up; the intermediate cement top is lapped above the previous shoe, not carried to surface — watch where the sage annuli start on the schematic.
↑ At surface, the derrick and BOP stack sit over the well while it's drilled and cased — they come off once the tree goes on.
DWell integrity

Two barriers, always

Nothing reaches the environment without passing two independent seals

  • Primary envelope: production tubing, packer, downhole safety valve, and the production casing & cement below the packer.
  • Secondary envelope: casing & cement above the packer, the wellhead, tubing hanger and christmas tree.
  • Both are tested at installation and monitored for the life of the well.
Try it Hit Primary then Secondary in the controls. Note the downhole safety valve lights up with the primary envelope — it isolates the tubing, the primary conduit.
EComplete

Connect the reservoir

Open or cased — two ways to let the rock flow

  • Cased & perforated: casing run and cemented across the pay, then perforated. Best for layered or weak formations needing selective control.
  • Open hole: reservoir left uncased, fluids enter directly. Fast and cheap in competent rock and horizontal wells — but little control over what flows.

Cased hole

  • Selective, zone-by-zone control
  • Works in weak, layered rock
  • More time, cost & kit

Open hole

  • Low cost, fast
  • Great in competent / horizontal rock
  • Less control over water & zones
↑ Toggle Cased & perforated / Open hole to swap the reservoir connection.
FSmart completion

Control the well without a rig

Split the reservoir and manage each zone from surface

  • Zonal isolation: packers divide the reservoir into separate compartments.
  • Flow-control valves (ICVs): each zone is opened, choked or shut from surface.
  • Sensors & control lines: pressure, temperature and flow measured in real time over hydraulic and fibre-optic lines.
Try it Switch Downhole control to Smart, then open, choke or shut each zone — the inflow arrows respond. You manage water or gas breakthrough with no rig visit; the trade-off is higher cost and downhole complexity.
GService through life

Wells are never left alone

Measure, maintain, improve — through a live well

  • Wireline — a thin cable carrying tools and data: logging, perforating, setting plugs, valve changes. Fast, but light tools only.
  • Coiled tubing — continuous pipe pushed in by an injector head. It brings force and can pump fluid while it moves: cleanouts, milling, acid washes.
  • Stimulation — matrix acidising below frac pressure to dissolve damage, or hydraulic fracturing above it with proppant to crack the rock open.
↑ Run each intervention with the Service the well controls — the spread swaps too: wireline unit, injector head & reel, or pump trucks on a surface tree; an LWI vessel & workover riser onto the XT in subsea.
HPlug & abandon

Give it back, permanently

Two verified barriers restore the seal — for good

  • Primary barrier plug across the reservoir — cement placed rock-to-rock so nothing can leave the pay zone.
  • Secondary barrier plug higher up: an independent backup that reseals the full cross-section.
  • Surface plug as a shallow environmental barrier, then the casing is cut and the wellhead or tree recovered.
Try it Switch End of life to Plug & abandon. The completion is pulled and cement plugs take over — the same two-barrier logic as production, only now permanent. It's the last, and least reversible, decision in the well's life.
↓ Works in both environments — subsea wells are cut below the mudline and the seabed is cleared.

03 — On the rig

Running the completion, day by day

A typical two-to-four-week programme between the last casing string and first production. Step through it.

1–3

Circulate clean & log the casing

Displace the drilling mud to a solids-free completion brine, then run logs to confirm casing and cement quality across the reservoir before anything is perforated.


04 — What to carry forward

One asset, from first hole to abandonment

Four ideas hold the whole life cycle together.

Principle

Barriers govern everything

Every phase is defined by two independent barriers and by pressure control. Lose that frame and nothing else matters.

Principle

Early choices last decades

Trajectory, casing sizes and completion type set the cost and the access you'll live with for the well's whole life.

Principle

Design for intervention

Subsea and surface equipment must support servicing, not just production — the well and its access are one design problem, not two.

Principle

Plan the ending

Abandonment is part of the design: cement plugs restore permanent isolation and the site is returned. Barriers, first hole to last.

01

Construction

Drill and case the hole, section by section.

02

Completion

Connect the reservoir and install the flow path.

03

Service

Intervene through life to keep it producing.

04

Abandonment

Plug with cement and restore the site.