GyroTracer, Stockholm Precision Tools’ north-seeking gyroscopic survey tool, is finding new users in the oil and gas sector. Offshore, it has been applied in wells off Italy and in the Persian Gulf, and it will soon be in action offshore Nigeria.

The latest generation of SPT’s downhole survey tool, the GyroTracer incorporates various improvements over the previous model, according to technical sales manager Shane Rawolle. Survey time is reduced by one third; the shock rating of the gyro module are increased by 50%, making the tool more robust; and the life of the battery module is increased by 80% from five to nine hours per run.

Preparing to run SPT’s north-seeking gyroscopic survey tool, GyroTracer. The tool is gaining acceptance offshore and onshore.

The software has been upgraded also to improve data acquisition and to provide more user-friendly features, driven largely by feedback from customers. Further upgrades are in the pipeline.

The battery module comes into play when the tool is used in memory mode, storing the survey data for downloading at the surface. It also can operate in wireline mode, with real-time transmission of data to the surface. In this case, power is supplied through the wireline.

The GyroTracer directly measures the earth’s rotation, which gives it a greater accuracy than tools based on indirect measurement. It is accurate to ±1º in azimuth, and has a repeatability of 0.5 in azimuth.

Unlike some survey tools, the GyroTracer requires no on-field calibration or roll-testing – it can go straight downhole. Nor is there any need to perform site alignment to find the starting azimuth, as is the case with some tools. The SPT tool has further advantages in that it can be moved between survey points at high speed without any risk of being knocked out of calibration and does not need to stop at random depths for a drift check.

While some tools need an extra running barrel or pressure barrel, the GyroTracer is a fully integrated tool, rated for pressures up to 15,000 psi (103 MPa). Even so, it is compact, measuring 2.3 m (7.5 ft) long and 42 mm (1.65-in.) in diameter.

Users can purchase a portable calibration stand and perform recalibration of the tool themselves on site, when required. The stand also functions for quality assurance testing.

For more information contact Shane Rawolle, Stockholm Precision Tools. Tel +46 8590 733 10, fax +46 8590 731 55, shane@stockholmprecisiontools.com, www.stockholmprecisiontools.com