Texas Instruments TI-58 IMCO Drilmod

Date of introduction:  1979 Display technology:  LED-stick
New price:   Display size:  10 (8 + 2)
Size:  6.4" x 3.2" x 1.5"
 162 x 81 x 37 mm3
Weight:  8.5 ounces, 240 grams Serial No:  
Batteries:  BP1A Date of manufacture:  
AC-Adapter:  AC9131 Origin of manufacture:  
Precision:  13 Integrated circuits:  TMC0540 (ZA5511)
Memories:  0-60    
Program steps:  480-0 Courtesy of:  Joerg Woerner

The innovative TI-59 was the perfect base for a lot of customized calculators. The idea behind these products was the novelty of the Solid State Software Modules™ with up to 5000 program steps.

The IMCO DrilMod application was developed in 1979 by IMCO Services, a division of Halliburton Co., Houston for both the TI-58 and TI-59. The module contains applications in the areas of well control, annular and bit hydraulics, directional design, d-exponents, cost/ft, and drilling mud, a total of 16 programs in all:

Kick. Two separate programs: one to calculate kill mud weight and a standpipe pressure schedule fir circulating out invading fluid. And another kick program designed especially for directional wells and wells with tapered drill strings.
Well geometry. Processes hole drill string data into annular sections and stores results for use by other programs.
Hydraulics: Calculates bit pressure loss, hydraulic hp, impact force, jet velocity, and annular velocity.
OP hydraul. Makes nozzle size determinations.
ECD-S/S. Computes equivalent mud weight under circulating or tripping conditions.
Build and hold. Calculates final angle information and measured depth in design of “build and hold” directional wells.
d-exponent. Calculates d- and dc-exponents.
Cost/ft. Makes cost/ft calculations.
Rheology. Computes n- and k-values and calculates shear stresses at various shear rates.
Spot. Makes basic calculations needed for spotting around drill collars.
Mud report. Makes calculations required for completing the top of the API drilling mud report.
Solids (unweighted muds). Calculates solids content of unweighted muds and D/B-ratio.
Slip velocity. Calculates cuttings slip velocities.
Solids (weighted muds). Analyzes solids content of weighted muds.
Critical velocity. Calculates critical velocities in the annulus.

IMCO Services. Published in May 28, 1979 edition of Oil Gas Journal. © 1979 by PennWell Publishing Company.

Don't miss the Optimum Mud Hydraulics application, developed later in 1979 by Magnet Cove Barium Corporation - better known as Magcobar. IMCO released a second module (“BossMod” for well-control operations) before anybody else and later developed a third module (“MudMod”) for internally use only.

We know five different approaches of the module expansion:

bulletStandard modules like the Master Library use only the small sticker above
the A,B,C,D, and E keys.
bulletOther modules like this Optimum Mud Hydraulics developed by Magnet 
Cove Barium Corporation
make use of a colorful keyboard mask.
bulletCustomized calculators like the USMC AV-8C calculator or insurance calculators
sold by Allianz and others use special keyboard arrangements.
bulletThe CAL-Q-TAX calculator uses an extender instead the usual drop-in modules.
bulletThe Kodak Q-700 Program Adapter makes use of a snap-on cover with an
individualized printing. 

Information about the DrilMod, BossMod and MudMod applications provided by Mario Zamora. Thanks!

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© Joerg Woerner, August 8, 2009. No reprints without written permission.