On a new project the hard part is the input data, not the calculation: you do not know yet what the trajectory will be, which friction factors to use, which mud, which bit. In aide.lite a well design is put together in eleven steps, and each step builds on what the earlier ones produced. At every step the app proposes a draft solution from the data known at that point. The engineer reviews it, corrects it where needed and accepts it with Apply. After every change, torque and drag, hydraulics, surge and swab, hole cleaning, ROP and the cost recalculate on their own.
1Project
Three groups of data:
the region, the pressure-window source and the temperature gradient, for the mud selection and the cementing; the region also sets the regional price adjustments;
a price book: rig, directional drilling, bits, muds, casing, cement;
Prices and times come filled in with default values. The well’s time and cost are built from them.
2Geomechanics & lithology
Load the mud window over depth (pore pressure and fracture gradient) and the lithology map: rocks, flags and complications by layer. Both tables are by true vertical depth subsea (TVDSS). This data is critical for choosing the casing shoe depths, screening the drilling fluid, and selecting the bit and the cementing class.
3Rig
A rig from the catalog of land rigs, or one entered by hand, sets the limits — hookload, torque, pump pressure and flow rate, tripping speed — and the day rate.
4Targets & trajectory
Every other calculation needs the trajectory. A known trajectory can be loaded; a new one can be designed automatically from the drilling targets and the constraints you set: kick-off point, angles, DLS. The result comes with a check of every constraint.
5Casing scheme
The casing scheme is built on a graph of standard hole–casing combinations. You usually start from the size the production requirements set, and the graph lights up the sizes allowed above and below it; the lower strings can be made liners. This gives a quick prototype of the well design.
6Section intervals
Next come the section depths. For a clear picture, the interval chart is drawn over the mud window and the lithology along the hole. This step is probably the most critical: the mud, bit and cementing programs, the drilling complications and the well’s cost all depend on it. For each section the app works out the dominant rock, the geological flags and the possible complications, and checks that the mud weight sits inside the interval’s mud window.
7Bit & ROP
This step runs mostly on its own: from the rock, the hole size and the pressures in the section, the app selects a PDC bit design, the weight on bit and the HSI, and estimates the torque on bit and the rate of penetration. They are needed later to optimize the drilling program and the well’s cost.
8Drilling fluid
The mud selector checks how well each of twelve fluid systems suits the section — by the mud window, the rocks and complications, the region and the price — and proposes up to three candidates per section. For each it selects the mud weight and the rheology for hole cleaning, and estimates the price per cubic metre.
9Drilling program
Now, for each section, the app selects:
the drill string;
the RPM and the flow rate, within the rig’s limits;
the directional drilling tier;
the friction factors, from statistical data.
From here on, torque and drag, hydraulics, surge and swab and hole cleaning are calculated for every section.
10Casing running program
The casing strings and the running parameters are refined. The friction factors, as in the drilling program, come from statistical data; torque and drag and surge and swab while running the casing are calculated with them.
11Cementing
For each section the app proposes a cementing scheme and a price class for every interval, depending on the geology and the conditions in the section. The rig time, waiting on cement included, is estimated separately. This gives the cost and the time of the cementing.
Result
From a minimum of input data you get a draft well design: the trajectory, the casing scheme, bits, muds, drill strings, casing strings, cement, the calculations for every run, the time and the cost, and a report in HTML or PDF. The draft is then refined section by section, in each section’s drilling and casing runs, and the calculations follow every edit.
The first 80% of a well design — in minutes, not weeks.
