The challenge

Placing a well in the right location can be the single biggest factor for a project's success or failure. We’ve all heard anecdotes of site surveys covering the wrong location, wells drilled or foundation structures installed in the wrong place. As we explore for smaller targets and positioning tolerances increase, the QA/QC of survey, navigation and positioning, plus associated geodetic controls, is becoming increasingly complex.

Positioning errors occur – and do so routinely – either as a result of incorrect co-ordinates, or more commonly, geodetic transformation and control issues.

For site investigations and surveys, the cost of repeating the acquisition of data – or returning to site to conduct infill lines – cannot be contemplated. With so much at stake, it is essential exhaustive checks are performed to assure the quality of the acquired data and mitigate any need to repeat work.

The solution

We provided a suite of innovative technologies to help our client drill a well at a site offshore West Africa. This included using our interactive Seekat® marine management platform to monitor vessel progress, providing real-time data to help make effective and timely decisions remotely.

During this particular operation, as the rig approached the drilling location, our real-time web-mapping showed that the rig was nearly 300m off the correct proposed location. The position of the rig and location target was displayed in real time from a satellite AIS feed and from our independent GPS transponder on the web map.

On review it was found that an incorrect geodetic transformation had been selected causing the positioning error.

Spotting the problem was not down to luck; the role of Inosys and the Seekat® virtual platform was pivotal. By identifying the error, we helped save significant costs and risk associated with spudding the well in the wrong location.