Since 1930, major oil companies and drilling contractors have used the M/D Totco Recorder to guide them in their efforts to drill vertical wells. During this time, the practice of controlled vertical drilling with the aid of the M/D Totco Recorder has become widespread. The art of drilling vertical wells without recourse to redrilling and the use of mechanical means of straightening to prevent or remedy deflection has become on established drilling practice. CVD reduces drilling time and brings about substantial savings in the drilling of every well. Successful application of CVD drilling methods depends on one vital factor: The driller must know accurately when any slight deviation occurs in the hole in order that he may properly adjust drilling weight and rotation speed to keep the course vertical. This necessitates a quick means of supplying the driller, at very frequent intervals, with extremely accurate and highly legible records of inclination. The M/D Totco Double Recorder gives correct information which is automatically double-checked.

SPECIFICATIONS
Environmental
+ Go-Devil: Pressure proof; for use in normal or extreme downhole temperatures up to 500 Degrees F (up to 260 degrees C).
+ Instrument: Should be stored in enclosure in Go-Devil or storage case.
Operating Temperature
+ Standard: Up to 200 degrees F (up to 93 degrees C)
+ Hot Well: Up to 500 degrees F (up to 260 degrees C)
Accuracy
+ ¼ of one degree
Sensor
+ Mechanical Timing Mechanism
Primary Power
+ Mechanical
Display
+ Two punched holes per chart
Enclosure Material
+ Standard: Stainless Steel
+ Air Unit: Aluminum
Optional
+ Angle Test Kit, Retrievable Centralizer, Overshot, Sinker Weight Unit, Baffle Plates, Special Subs

Provides two critical recordings
The heart of the Drift Indicator System is the Double Recorder which consists of two main parts: an angle indicator and a timing device. Both are sealed in a stainless steel case.

Self checking to provide accuracy
The Double Recorder checks itself so you are assured of an accurate reading. It does so by producing a permanent record of hole inclination by perforating a small circular chart close to the center of the chart if you’re drilling thru vertical; or off center in a concentric circle to show you the degree of deviation. Then it repeats this process a few seconds later. If the two perforations are the same deviation, the record is accurate. If they vary, another set of readings should be taken to insure accuracy.

Minimal equipment required for readings
Very little equipment is needed to accomplish the reading procedure: a Double Recorder; the Go-Devil assembly which protects it against shock, pressure and fluid; plus a selection of centering equipment.

Reduce time spent to perform survey measurements and improve efficiency of course corrections in holes that have become deviated. NOV M/D Totco® now offers a Multi-shot Reader and e-Totco® (150°C) tool with significant advantages over single shot tools to reduce overall surveying time and costs in drilling vertical boreholes. The e-Totco electronic survey tool improves accuracy and offers enhanced reliability and “user friendliness.” Multi-Shot Surveys, while tripping-out of hole, allows drillers to avoid expensive and unproductive time caused by stuck pipe by maintaining circulation and drilling past formations which may cause stuck pipe.

Compatible with all industry standard pressure barrels
The e-Totco tool is a “drop-in” replacement for all vertical mechanical CVD instruments. The compact, robust electronic package is designed to be used with the rig’s existing running gear including the standard NOV M/D Totco pressure barrel (Go-Devil), c pressure barrels owned by drilling contractors around the world.

Survey on Demand
Push a button and the display will lead you through the survey procedure. No more waiting for a preset clock to take survey, eliminating the timing guesswork associated with running mechanical surveys means a more efficient, cost effective, and reliable way of optimizing Controlled Vertical Drift (CVD) measurements. Multi-Shot capability allows you to select up to 64 surveys per run by just pushing a button when the Go-devil reaches desired depth. In addition, it provides a manual depth entry option, which allows correlation of survey measurement and well temperature with corresponding depth on the printed survey ticket.

Better resolution than mechanical surveys
The e-Totco instrument has an electronic sensing system that produces 0.05% repeatability of survey records and 1% reading accuracy [±0.1°].

Greater Range - Up to 20 degrees
One E-Totco instrument provides all mechanical CVD instrument ranges: (1-1/2°, 3°, 7°, 8°, 14°, 16°, and 20°).

Records Downhole Temperature
The e-Totco records the wellbore temperature at the survey depth and can be extrapolated to TD using depth gradient.

e-Totco High Temp (150°C)
+ Operating Temperature: 10° to 150° C (50° to 302°F)
+ Survival Temperature : -20° to 165°C (-4° to 329°F)

Feature	Benefits
64 Shots Per Survey Run	Multi-Shot capability saves rig time. The Multi-shot Reader provides the ability to select up to 64 surveys in one trip.
Depth to Survey Correlation	Improve your drilling efficiency.  Depth entry allows drillers to correlate survey measurements to depth and determine where a hole became highly deviated in one trip.
Data Logging	Stores crucial reporting data. Multi-Shot Reader provides printed survey records and stores up to 1600 records which can be exported to a PC for analysis and reporting.
Up to 150°C (302°F) Operation	Greater depth capability. Higher operating temperature provides continued rig time savings by no longer being forced to use a mechanical drift instrument in high temperature wells.
9 hour Survey times (adjustable 5 to 18 hours)	Extended survey measurement run time. Tool takes readings continuously every 30 seconds for up to 9 hours or adjustable up to one survey every 60 seconds for 18 hour run time.
Time Synchronization	Reduce rig time to run survey. Time synchronization of surveys eliminates timing guess work to run survey and waiting for the clock time to run down. In addition, time synchronization reduces risk of missed or moving surveys.