The battery powered rate gyroscopic surveyor (RGS-BT) is a major advancement in operational versatility, and it offers significant cost-savings by eliminating electric wireline.
With the introduction of RGS-BT in 1994, a rate-gyro survey for the first time could be run inside drillpipe while tripping out of the hole, just like a magnetic tool.
However, due to its sensitivity to shock, the tool could not be dropped like a magnetic tool. It had to be lowered on slick line and released. This involved extra time and expense to rig and run the line, and the pipe could not be rotated with the line in the hole.
Drop Gyro System
Using a proprietary high shock rated gyroscopic sensor (the X-4™), the drop battery system (RGS-DP) can be dropped and pumped down to bottom in drillpipe at speeds of up to 1000ft/min without the requirement for slick or braided line. If due to unforeseen circumstances hole conditions deteriorate while tripping out and back reaming is required, the sensor is capable of withstanding the increased levels of shock and vibration normally seen during this kind of operation.
Considering the cost of today’s operations, reducing rigtime by 5-10 or more hours and eliminating electric wireline and other associated costs can easily add up to significant savings.
- Saves rigtime by running during the trip out of the hole in drillpipe, compared to a normal gyro run on electric line in casing.
- Eliminates rig-up time, run time and crew costs for slick or braided line in drillpipe run.
- Allows pumping and rotating while being dropped to prevent stuck pipe.
- Virtually no depth limitation with up to 32 hours of run power and storage for 8,190 survey readings.
- No wait at a connection during the trip out to take survey information.
- Provides rate-gyroscopic survey accuracy in drillpipe prior to running casing, and also surveys upper casing strings during the run in drillpipe.
The drop system is connected to the surface computer to check system functionality. The tool is then rigged up and pumped downhole during circulation prior to tripping. Although the pipe can be rotated, backreaming is not recommended. Survey data is collected at each connection while tripping out and depth is entered versus time. Upon retrieval of the tool at surface, survey data downloads immediately to the laptop computer.
|Type||RGS Drop System (RGS-DP)|
|Sensor performance||±0.05° Inclination, ±0.1° Azimuth, ±0.05° Tool face (1 sigma)|
|System performance||SPE WPTS approved models|
|Delay settings||1-255 minutes|
|Survey station interval||15-30 seconds|
|Battery operating time||8-32 hours|
|Memory storage||over 8,190 survey readings|