Well Construction
A well is a pressure vessel you build blind.
Everything we do between spud and rig release exists to hand over a wellbore that holds pressure for thirty years and takes a completion string without an argument.
Sequence
How a well gets built
Site & conductor
Pad civils, cellar, conductor driven or drilled to competent ground. On multi-well pads we set every conductor before the rig arrives so the rig walks straight into the next slot.
Surface hole
Large-diameter hole through the fresh water intervals, cased and cemented to surface. This is the string that protects the aquifer, and it is the one we never take a shortcut on.
Intermediate
Through the transition and any lost-circulation or over-pressured intervals. Where the margin is narrow we drill it with managed pressure and frequently save a string.
Curve
Build section on a rotary steerable, typically 8–12° per hundred feet, landing within a few feet of target true vertical depth.
Lateral
Geosteered against gamma and resistivity to keep the wellbore in the target window. Our twelve-month average is 94.6% of lateral footage in zone.
Production string
Casing or liner run, cemented and pressure tested. Cement bond logged and the result handed over whether or not it flatters us.
Completion interface
Wellhead dressed, BOP nippled down, tree installed and the well handed to the completions contractor on a documented interface with a joint walkdown.
Rig release
Location restored to the agreed condition, all data uploaded, and the rig moved. Release time is logged to the minute because it is the number everybody is paid against.
End of well report
Full construction record: every survey, every cement job, every deviation, every hour of non-productive time and what caused it. Issued within ten working days.
Typical design
Permian lateral — representative casing programme
| String | Hole size | Casing OD | Weight | Grade | Shoe MD | Cement |
|---|---|---|---|---|---|---|
| Conductor | 26" | 20" | 94 lb/ft | H-40 | 120 ft | Driven |
| Surface | 17½" | 13⅜" | 61 lb/ft | J-55 | 3,180 ft | To surface |
| Intermediate | 12¼" | 9⅝" | 47 lb/ft | P-110 | 11,640 ft | 1,500 ft above shoe |
| Production | 8½" | 5½" liner | 20 lb/ft | P-110 | 20,400 ft | Full lateral |
Representative only. Every well is designed against the operator's own pore pressure and fracture gradient data.
Cementing & integrity
The job nobody sees and everybody depends on.
A bad primary cement job is the most expensive mistake available on a drilling rig, and it is invisible until it is not. We treat it as an engineered operation rather than a pumping service: centraliser placement modelled, hole cleaned to a measured standard before the job, returns monitored volumetrically, and a bond log run on every production string.
Where the bond is marginal we say so and we squeeze it. We have never handed over a well with a bond log we would not put our own name against.
- Centraliser standoff modelled to a 70% minimum
- Hole cleaned to a measured cuttings-return standard before cementing
- Volumetric returns monitoring throughout the job
- Cement bond log run and issued on every production string
- Annular pressure monitored through the completion handover
Performance
Well construction, since start-up
How we take work.
Xtragate does not tender publicly and does not accept unsolicited enquiries. Programmes come to us through operators we already work for.