Choosing a system by well condition
Temperature, data rate and vibration tolerance are asked for very differently from one well type to the next. Find your well here first, then we can talk about which tools to run.
HPHT deep wells
In a hot well the electronics, seals, batteries and greases each have their own failure temperature, and most of them fail progressively: the readings drift first, the function is lost later. What has to be established for the job is this — after twenty hours close to its 175 °C rating, is the tool still measuring within spec?
Routine operationsOnshore directional & horizontal wells
Sliding is steered on toolface, so a long update interval eats straight into drilling time. What these wells really care about is not peak data rate but the toolface update interval and how quickly a downlink is answered.
Long lateralsShale gas & tight oil
Down a long lateral the mud pulse attenuates, the pulse shape spreads, and noise from the pumps and from drillstring vibration rises at the same time. Most lost data is not a tool failure; it is the decoder failing to keep up with a changing channel.
Heat · corrosionGeothermal wells
On top of sustained heat, geothermal wells often carry corrosive fluids, and the circulating medium is not necessarily a conductive mud. We state our limits for these wells item by item, and say plainly when a job falls outside them.
Slim hole · cost-drivenCBM & shallow wells
CBM and shallow wells mostly run slim tools and are often drilled on air or foam. Mud pulse will not work in those conditions, so electromagnetic telemetry is used instead.