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Product

instrumentation cable series7-Conductor Heptacable3/8" · 27/64" · 15/32"Up to +260 °C & 98 kN

7Q38 / 7H42 / 7J46 Seven-Conductor Armoured Wireline LoggingAPI RP 9B 7-conductor double-armoured open-hole wireline logging cable

7Q38 (.390" / 9.91 mm), 7H42 (.422" / 10.72 mm) and 7J46 (.464" / 11.79 mm) Seven-Conductor Double-Armoured Wireline Logging Cable with 1+6 tinned/nickel copper conductors, ETFE/FEP/PFA insulation, void-filler matrix and.

Torque-Balanced 2-Layer
Drilling Mud & Gas Immune
175 MPa Hydrostatic
API RP 9B
Order designation
7Q38 (.390" ETFE)
Nominal outer Ø
9.91 mm
Weight in air
372 kg/km
Breaking strength
64.5 kN
Conductor DC R
33.5 Ω/km
All sizes (4)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Construction
7C (1 + 6 core)
6 outer around 1 centre
Standard ODs
.390"/.422"/.464
9.91 / 10.72 / 11.79 mm
Breaking load
64.5 to 97.9 kN
14,500 to 22,000 lbf
Temperature
+165 to +260 °C
ETFE (Q) / FEP (H) / PFA (J)
Voltage rating
1,000 to 1,500 V
High-power tool telemetry
Telemetry modes
7 orthogonal mod
Up to 2–4 Mbps open-hole

Typical values for this cable type, based on API RP 9B / ASTM A475 / NACE MR0175 — confirmed in the datasheet and quotation for your order.

Application fit

Is 7Q38 / 7H42 / 7J46 right for your machine?

Industry-standard 7-conductor ('heptacable') open-hole wireline for multi-sensor formation evaluation, NMR, borehole seismic, micro-resistivity imaging and rotary sidewall coring.

Drilling jumbo & rotary mast feed

Suitable

Powers high-wattage open-hole imaging, acoustic, nuclear and formation-testing strings over 7,500+ m.

Vertical / spreader reel

Suitable

Pre-stressed contra-helical double steel wire armour keeps zero-torque balance and < 1.2 m/km/5 kN stretch.

Immersion & wet locations

Suitable

Elastomeric/fluoropolymer void-filler matrix resists gas invasion and decompression up to 175 MPa.

Energy chain / drag chain

Not suitable

High-tension downhole wireline logging cable; not for factory cable drag chains.

Use PUR-HF Drag-Chain Cable
Typical machinesOpen-Hole Formation Evaluation (Triple/Quad Combo)NMR, Borehole Acoustic & Micro-Imager LoggingFormation Fluid Sampling & Sidewall CoringVSP Borehole Seismic & Deep Geothermal WellsSour Gas (MP35N / Alloy 27-7MO) Open-Hole Logging

Construction

Layer by layer

7Q38 / 7H42 / 7J46 heptacable showing 1 central + 6 helical tinned/nickel copper conductors, ETFE/FEP/PFA primary insulation, high-temperature void-free bedding matrix, and inner + outer contra-helical GIPS/UHS steel wire armour.

1234
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
17 × stranded tinned/nickel copper conductors (1+6)1 central + 6 helically stranded 19-wire compacted tinned or nickel-plated copper conductors (22–20 AWG)Symmetrical heptacable geometry enables 7 orthogonal telemetry modes
2Code Q / H / J fluoropolymer core insulationCross-linked ETFE ('Q', +165 °C), FEP/Copolymer ('H', +205 °C), or PFA ('J', +260 °C) high-dielectric insulationWithstands 1,000–1,500 V AC/DC tool power
3Void-free elastomeric/fluoropolymer interstitial fillerExtruded high-temperature fluoroelastomer filler & binder tape sealing all core valleysPrevents downhole gas migration and armour key-seating into cores
4Inner & outer contra-helical steel wire armour2 layers (typically 18 inner + 24 outer wires) of GIPS, UHS/EHS, Nitronic 50 or MP35N sour-service alloyPre-formed and hot-stretched for depth accuracy

7Q38 (.390 in · 9.91 mm ETFE)

3/8" high-speed open-hole heptacable rated +165 °C and 64.5 kN (14,500 lbf) breaking load

7H42 (.422 in · 10.72 mm HT)

27/64" high-temperature (+205 °C) heptacable rated 77.8 kN (17,500 lbf) breaking load

7J46 (.464 in · 11.79 mm PFA)

15/32" heavy-duty deep hot-hole (+260 °C PFA) heptacable rated 93.4 kN (21,000 lbf)

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on API RP 9B / ASTM A475 / NACE MR0175. Values for your order are confirmed in the datasheet and quotation.

Electrical

Voltage rating
1,000 V rms (7Q38) · 1,200 V rms (7H42) · 1,500 V rms (7J46)
Conductor DC R @ 20 °C
33.5 Ω/km (7Q38) · 29.8 Ω/km (7H42) · 24.6 Ω/km (7J46)
Armour return resistance
3.8 Ω/km (7Q38) · 3.2 Ω/km (7H42) · 2.6 Ω/km (7J46)
Insulation resistance
≥ 15,000 MΩ·km @ 500 V DC (20 °C)

Thermal

7Q38 continuous rating
-40 °C to +165 °C (+330 °F) — Cross-linked ETFE
7H42 continuous rating
-40 °C to +205 °C (+400 °F) — Fluoropolymer HT
7J46 continuous rating
-40 °C to +260 °C (+500 °F) — PFA Ultra-HT

Mechanical

Min. breaking strength
64.5 kN (7Q38) · 77.8 kN (7H42) · 93.4 kN (7J46)
Stretch coefficient
0.95 to 1.25 m / km / 5 kN (factory hot pre-stretched)
Min. sheave diameter
560 mm / 22" (7Q38) · 610 mm / 24" (7H42) · 660 mm / 26" (7J46)

Resistance

Hydrostatic well pressure
Up to 175 MPa (25,000 psi)
Sour well H₂S option
Available with Nitronic 50 or MP35N armour per NACE MR0175
Gas decompression
Void-filled core bedding prevents gas pocket blowouts

Reference standards

Wireline standard
API RP 9B (Application, Care & Use of Wire Rope)
Sour service standard
NACE MR0175 / ISO 15156 (alloy armour variants)
RoHS & REACH
2011/65/EU & EC 1907/2006 compliant

Identification

Core identification
Centre #7 Black; outer ring #1–#6 clockwise numbered/coloured
Customs tariff (HS)
8544.4993
Reel documentation
API RP 9B pull-break certificate, stretch chart & OTDR/TDR log

Sizes

4 standard 7-conductor wireline logging configurations

Nominal diameter, weight in air, breaking strength and conductor DC resistance.

Dimensions, weight & breaking load
Order designationNominal size & insulationNominal Ø
mm		Weight in air
kg/km		Break load
kN		Cond. DC R
Ω/km		Enquiry
7-Conductor Double-Armoured Wireline Logging Cables
7Q38 (.390" ETFE)3/8" (.390") · +165 °C ETFE · GIPS9.9137264.533.5
7Q38-UHS (.390" High-Strength)3/8" (.390") · +165 °C ETFE · UHS9.9137875.633.5
7H42 (.422" HT)27/64" (.422") · +205 °C FEP · GIPS10.7243877.829.8
7J46 (.464" PFA Ultra-HT)15/32" (.464") · +260 °C PFA · UHS11.7953693.424.6
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • Supplied pre-seasoned and hot-stretched in continuous lengths up to 9,150 m (30,000 ft) on steel logging drums.

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

  1. ConductorClass 5 stranding
  2. Spark test100 % in-line
  3. Lay-upCores, earth, fillers
  4. SheathingInner, braid / screen, outer
  5. Electrical testsAC voltage, resistance
  6. DimensionsOD, wall thickness
  7. Inspection documents & dispatchDrum & dispatch
Testing & inspectionTest value / referenceFrequency
Routine tests
100 % 3.5 kV AC dielectric, IR, TDR impedance & laser OD profileZero breakdown, IR ≥ 15 GΩ·km and OD within +0.10 / -0.05 mmEvery manufactured logging length
Sample tests
Full-scale tensile break & torque-rotation balance testMeets ≥ 64.5–93.4 kN break load with < 15°/m free-end rotationPer production lot
Hot-stretch seasoning & thermal-pressure cyclingEliminates permanent constructional stretch prior to field deploymentEvery logging reel

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

API RP 9B Wireline CompliantASTM A475 / UHS Armour GradeNACE MR0175 (MP35N Option)

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

Stamped metal reel tag: TEBAOFLEX 7Q38 / 7H42 / 7J46 HEPTACABLE
Delivery form
Fumigated wooden drums, steel reels or precision spools
Standard lengths
500 m · 1000 m (or custom cut/spooled lengths)
MOQ
100 m (standard) · 500 m (custom)
Lead time
2–4 weeks ex-works
Incoterms
EXW, FOB, CIF, DAP

Technical documents

Downloads

PDF7Q38 / 7H42 / 7J46 Seven-Conductor Armoured Wireline Logging – technical datasheet4 sizes · construction, technical data, approvalsXLSX7Q38 / 7H42 / 7J46 spec data (Excel)All 4 sizes with dimensions and data, for your BOM or quotation
Revision
2026-10-20
Updated
2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

How do the 7Q38, 7H42 and 7J46 designations decode in oilfield wireline nomenclature?
The leading '7' indicates 7 insulated conductors (1 central + 6 outer). The middle letter indicates the fluoropolymer insulation temperature rating ('Q' = Cross-linked ETFE +165 °C; 'H' = High-temp fluoropolymer +205 °C; 'J' = PFA +260 °C). The two digits indicate the nominal diameter in 64ths of an inch or hundredths ('38' ≈ 25/64" or 0.390" / 9.91 mm; '42' = 27/64" or 0.422" / 10.72 mm; '46' = 30/64" or 0.464" / 11.79 mm).
How does a 7-conductor heptacable achieve multi-megabit telemetry rates over 7,500 m?
Because six identical outer conductors are arranged symmetrically around one central conductor inside a conductive steel armour shield, surface telemetry modems excite up to 7 orthogonal propagation modes (such as opposite-pair differential modes for high-frequency data and phantom/centre modes for high-wattage downhole tool power) with minimal modal crosstalk.
Why is factory hot-stretching (seasoning) important for open-hole logging cables?
Open-hole depth logs must correlate within centimetres across multiple runs. Hot-stretching the finished wireline under tension and temperature seats the contra-helical armour wires into the elastomeric bedding, removing permanent constructional elongation.
Can 7Q38 / 7H42 / 7J46 be supplied with optical fibres in the centre?
Yes. Hybrid electro-optical heptacables replacing the central copper conductor with a hermetically sealed 316L stainless-steel tube (FIMT) containing 2 to 4 single-mode or multimode fibres are available on request.

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