# DrillX

> DrillX is drilling operations software for drilling contractors, oilfield service companies and operators, published by Culturetek PTE LTD (Singapore). It is in final testing; subscriptions open soon. Contact info@drillx.app for a demo or early access. Available in English and Arabic.

## Features
- Daily drilling reports: IADC-style time logs. DrillX checks each report as you type, flags lost time and catches errors such as depth at 24:00 shallower than at 00:00, or footage with no drilling time logged.
- Rig fleet view: The live position of every rig from its latest daily report, with numbers for the last 7 days.
- NPT insights: Where rig time is being lost and which problems keep coming back: non-productive time by cause over the last 30 days, and recurring problems flagged.
- Engineering calculators: Standard oilfield formulas in field units, updating as you type, including a Driller's and Wait & Weight kill sheet.

## Engineering calculators
- Hydrostatic pressure
- Equivalent circulating density (ECD)
- Annular pressure loss
- MAASP from leak-off test
- Triplex pump output and volumetric efficiency
- Annular capacity and velocity
- Buoyancy and string weight
- Well control kill sheet: Driller's and Wait & Weight methods, initial and final circulating pressure

Calculators are advisory only; always follow approved well-control procedures and the rig's kill sheet.

## Guides
- [Hydrostatic pressure formula in drilling](https://drillx.app/hydrostatic-pressure-formula/): the formula in field and metric units (psi = 0.052 × mud weight in ppg × TVD in ft; kPa = 0.00981 × kg/m³ × TVD in m), where the constant 0.052 comes from, a gradient table by mud weight, and worked examples for deviated wells and mixed fluid columns.
- [Kill sheet calculations, step by step](https://drillx.app/kill-sheet-calculations/): kill mud weight, ICP, FCP, step-down schedule and MAASP in field units, with a worked example and the Driller's vs Wait & Weight methods compared.
- [Equivalent circulating density (ECD), explained](https://drillx.app/equivalent-circulating-density/): the ECD formula in field units (ECD = MW + annular pressure loss ÷ (0.052 × TVD)), a worked example at the bit and at the casing shoe, what raises ECD and how to lower it.
- [MAASP and leak-off test calculations](https://drillx.app/maasp-leak-off-test/): the MAASP formula in field units (MAASP = (LOT EMW − mud weight) × 0.052 × shoe TVD), how to turn a leak-off test into an equivalent mud weight, a worked example, a table of MAASP by mud weight, LOT vs FIT and the limits of MAASP.
- [Annular velocity and annular capacity formulas](https://drillx.app/annular-velocity-formula/): the formulas in field and metric units (annular velocity in ft/min = 24.5 × flow rate in gpm ÷ (Dh² − Dp²); annular capacity in bbl/ft = (Dh² − Dp²) ÷ 1029.4), where 1029.4 and 24.5 come from, worked examples for velocity around drill pipe and collars, annular volume and bottoms-up strokes, and common mistakes.
- [Triplex pump output formula and volumetric efficiency](https://drillx.app/triplex-pump-output-formula/): the formula in field units (bbl/stk = 0.000243 × liner ID² in inches × stroke length in inches × efficiency), where 0.000243 comes from, a table by liner size, how to measure volumetric efficiency, duplex and quintuplex formulas, and converting output to gpm, strokes and minutes.
- [Buoyancy factor formula and buoyed string weight](https://drillx.app/buoyancy-factor-formula/): the formula in field and metric units (BF = 1 − mud weight in ppg ÷ 65.5; BF = 1 − SG ÷ 7.85), where 65.5 comes from, buoyed weight of drill pipe and collars with a worked example, a table by mud weight, the general formula for different fluids inside and outside the pipe, and how buoyed BHA weight sets weight on bit and the neutral point.
- [Ton-mile calculation for drilling line](https://drillx.app/ton-mile-calculation/): round-trip ton-miles Tr = [D × (Ls + D) × Wm + 4 × D × (M + ½C)] ÷ 10,560,000, drilling (3 × (T2 − T1)), coring (2 × (T4 − T3)), short-trip and casing ton-miles, a worked example, and how ton-miles drive the slip-and-cut program under API RP 9B.
- [Annular pressure loss formula](https://drillx.app/annular-pressure-loss-formula/): Bingham plastic annular pressure loss in field units (laminar: psi/ft = PV × V ÷ (1000 × (Dh − Dp)²) + YP ÷ (200 × (Dh − Dp)), V in ft/s; turbulent: MW^0.75 × V^1.75 × PV^0.25 ÷ (1396 × (Dh − Dp)^1.25)), critical velocity to pick the flow regime, a two-section worked example (drill pipe and collars) carried through to ECD, what raises APL and the limits of quick formulas.
- [Drill pipe capacity and displacement](https://drillx.app/drill-pipe-capacity-displacement/): capacity (bbl/ft = ID² ÷ 1029.4), open-ended displacement ((OD² − ID²) ÷ 1029.4) and closed-end displacement (OD² ÷ 1029.4), a table for common API drill pipe sizes and drill collars, tool-joint allowance (adjusted weight ÷ 2,747), string volume and trip tank worked examples, level drop and hydrostatic loss pulling dry or wet, and common mistakes.
- [IADC daily drilling report codes, explained](https://drillx.app/iadc-ddr-codes/): the IADC DDR Plus (March 2019, 34 main codes, activity and equipment sub-codes, WITSML-based schema); each main code (2 drilling, 6 trips, 7 service rig, 8 repair rig, 12 casing and cement, 13 WOC, 19 fishing, 33 operating status, 34 safety, 35 well control) with start/stop rules; how NPT and invisible lost time are recorded; common DDR errors. Not the same as IADC bit codes.
- [NPT in drilling: nonproductive time, explained](https://drillx.app/npt-drilling/): what counts as nonproductive time (repair, fishing, well control, losses, stuck pipe, waiting); NPT % = NPT hours / total rig hours x 100; NPT cost = NPT hours / 24 x spread rate; worked example (86.4 h of 720 h = 12%, $216,000 at an illustrative $60,000/day); main causes by group and IADC code; invisible lost time (1 extra minute per connection over a 10,000-ft section = 100 minutes); how to reduce NPT; sources Drilling Contractor 2010 and 2013, IADC DDR Plus.
- [Kill mud weight and kick tolerance, calculated](https://drillx.app/kill-mud-weight-kick-tolerance/): kill mud weight formula in field units (KMW = OMW + SIDPP / (0.052 x TVD), or OMW + SIDPP x 19.23 / TVD), ICP = SCR + SIDPP, FCP = SCR x KMW / OMW, barite weight-up (sx/100 bbl = 1,470 x (KMW - OMW) / (35 - KMW)); deviated-well worked example (450 psi SIDPP, 11,800 ft TVD, 11.2 ppg -> 12.0 ppg; ICP 1,200 psi, FCP ~804 psi); KMW lookup table by SIDPP and TVD; kick tolerance definition (NORSOK D-010 via IADC Lexicon) and single-bubble volume method (Hmax = (MAASP - SIDPP) / (Gm - Gi), V1 via Boyle's law, V2 around the BHA, KT = smaller) with a worked example (~70 bbl at 0.5 ppg); sources Drilling Contractor 2010, SPE Petroleum Engineering Handbook, Bourgoyne, Lapeyrouse.
- [Stuck pipe: differential vs mechanical, and the free point formula](https://drillx.app/stuck-pipe-free-point/): stuck pipe mechanisms (differential sticking, pack-off and bridging, wellbore geometry, junk and cement); diagnosis table by pipe motion, rotation and circulation; differential sticking force F = f x dP x Ac (f < 0.04 oil-based to 0.35 weighted water-based mud, PetroWiki) with a worked example (983 psi, 720 sq in, ~142,000 lb at f = 0.2); free point from stretch, L (ft) = e (in) x As x 2,500,000 / pull (lb), free point constant = As x 2,500, weight form 735,294 x e x Wpe / pull; worked example for 5 in 19.50 lb/ft pipe (24 in stretch at 40,000 lb = ~7,910 ft; nominal weight overstates by ~9%); overpull limit; first actions by mechanism. DrillX has no free point calculator.
- [Swab and surge pressure, and the trip margin formula](https://drillx.app/swab-surge-pressure-trip-margin/): what surge (running in, raises bottomhole pressure, losses risk) and swab (pulling out, lowers it, kick risk) are and what makes them worse; quick steady-state Bingham estimate for closed-end pipe (Va = Vp x Dp^2 / (Dh^2 - Dp^2), effective V = Va + 0.45 x Vp with Burkhardt clinging constant, psi/ft = PV x V / (1000 x (Dh - Dp)^2) + YP / (200 x (Dh - Dp)), max pipe speed = 1.5 x average); worked example (5 in pipe, 8.5 in hole, 10,000 ft, 12.0 ppg, PV 25, YP 15, 93 ft stand in 60 s = ~261 psi = ~0.50 ppg); maximum tripping speed for an allowed surge (0.6 ppg -> stand no faster than ~29 s); trip margin TM = YP / (11.7 x (Dh - Dp)) (11.7 = 225 x 0.052; example 0.37 ppg); trip sheet signs of swabbing and flow checks; ways to reduce surge and swab; limits of the Bingham model (API RP 13D, dynamic models). DrillX has no surge-swab simulator.
- [Bit hydraulics: nozzle TFA, jet velocity and HSI](https://drillx.app/bit-hydraulics-nozzle-tfa-hsi/): total flow area TFA = sum of 0.7854 x (n/32)^2 per nozzle with a TFA table (8/32 to 20/32, 1 and 3-6 nozzles); jet velocity Vn = 0.3208 x Q / TFA; bit pressure drop = MW x Q^2 / (10,858 x TFA^2) (Cd 0.95); bit hydraulic horsepower = dP x Q / 1714; HSI = 1.27 x HHPb / D^2; impact force = MW x Vn x Q / 1930; worked example (12-1/4 in bit, 3 x 14/32, 650 gpm, 10.5 ppg: TFA 0.451 in2, ~462 ft/s, ~2,010 psi = 63% of 3,200 psi, ~762 hhp, HSI ~6.4, ~1,635 lbf); nozzle selection from a target pressure drop (about 65% of pump pressure for maximum bit hydraulic horsepower, about 48% for maximum impact force, Bourgoyne ADE ch. 4); checks before changing nozzles. DrillX has no nozzle calculator.

## Full content
- [llms-full.txt](https://drillx.app/llms-full.txt): plain-text copy of every guide

## Questions
- What is DrillX? DrillX is drilling operations software for drilling contractors, service companies and operators: daily drilling reports, a rig fleet view, non-productive time (NPT) insights and engineering calculators, in English and Arabic.
- When will DrillX open? DrillX is in final testing while payment setup is completed. Subscriptions open soon; email info@drillx.app for a demo or early access.
- Does DrillX replace well-control procedures? No. The calculators are advisory only. Always follow your approved well-control procedures and the rig's kill sheet.
- Who publishes DrillX? DrillX is published by Culturetek PTE LTD, Singapore.
- Which languages does DrillX support? English and Arabic.