In an industry that demands hardware in sizes and capacities that often run to the enormous —with capabilities to match — it’s nice to see a downhole tool come along that is compact, simple and performs a few simple but highly useful tasks.

From National Oilwell Varco’s Russell Subsurface Systems division comes such a tool.
The RSS Data Logger is a nifty little downhole Swiss army knife that performs a number of useful measurements. It’s a downhole vibration logger, motor-hour counter, downhole temperature logger, orientation monitor, service interval reckoner and a “spy in the string” for rental tools. It also complements other drilling data such as torque and rate of penetration in final well reports.

It’s not much bigger than a Swiss army knife, either. The instrument outside diameter is 0.75 in. (19.0 mm); length is 3.64 in. (92.75 mm). It has a pressure rating of 20,000 psi and a temperature rating of 302ºF (150ºC). The company says the tool can be fitted into a modified collar in the drill string, a pocket in the rotor, in a modified fishing neck or in the bullnose of an measurement-while-drilling string.

Integral accelerometers in the tool measure vibration exerted along two axes when a mud motor (or other equipment) is running. The tool records the average vibration at time intervals determined by the engineer and has an adjustable vibration threshold that enables the engineer to set a base level below which it will not record.

Downhole temperature can be recorded as well as vibration. Temperature data is available in the same way as the vibration data and both can be presented in a graphical format for easy interpretation. The tool can also be used as an orientation device using two accelerometers, (X, Y axes) to confirm orientation of tools in hole.

The tool can be connected to a PC via a purpose-built interface. This allows communication via a standard USB port which also serves to power the tool while it is connected to the PC. A Windows-based program provides the operator with the means to access the special functions provided by the tool.

The tool is fitted with a replaceable, long-life battery (the company says approximately two years) that powers the onboard circuitry. Battery usage is recorded in order to give the operator an indication of remaining battery life. All data is stored in non-volatile EEPROM. The tool has a battery saving mode when not immediately required for use.

The results screen displays basic information downloaded from the tool. Displayed among other data are the time duration of the last run, the number of vibration samples collected during the run (which is configurable) and the tool’s serial number. A graph presents vibration and temperature recorded during the last run. If a detailed assessment of a particular part of the run is required the graphical representation of the data can be reset to show a small part of the results. This enables engineers to determine if something in particular occurred in a drilling operation by looking at the high or low vibration measured at that time.

On another subject, those clever Scottish engineers are at it again. The case in point is something called No Waste Drilling by its developer, Seimtec Limited of Aberdeen. The company is apparently out to lay waste, so to speak, to the drilling waste management industry, which the company says prospers from this problem to the tune of US $1 billion annually.
They intend to do it with a natural aqueous erosion process soon to begin offshore trials after being proven onshore. Called InPro, it’s said to be a unique process that embeds the capability to eliminate waste directly into drilling workflow.

The modular system integrates into the drilling process as an enhancement of the solids control system. The result is a solids control system where reconditioned mud and recovered oil are either returned to the active mud system or stored for reuse. The cleaned cuttings can then be safely returned (within legislative limits).

The company says other advantages over drilling waste management systems include no need for a dedicated energy supply or excessive deck space, quick rig-up, quiet running, no excessive vibration and no heat during operation, all of which contribute to onboard safety. The process doesn’t change the physical properties or the nature of materials, so it protects recovered muds and base oils, according to the company. The system’s energy efficiency also gives it a small carbon footprint and low environmental impact.

The system’s throughput will keep pace with drilling up to 17.5-in. holes without the need for buffer storage, controlled drilling or unscheduled wiper trips, although backup buffer storage may be required.

It’s no surprise that this is yet another product of Scotland, a magical land where engineering feats seem to emanate far out of proportion to the population. One of these days, someone is going to discover the connection between engineering proclivity and golf and why the world’s most fiendishly difficult game could only have been invented there.