14.6 DTS Measurements

As mentioned previously, DTS measurements are obtained from a DTS installed system, and can contain both the ‘raw’ measurement and the interpreted temperature log curves (Figure 14.6-1). Both types are actually optional, depending on the situation and the requirements for that particular installation. DTS Measurement is another top-level object.

Every DTS Measurement object contains a mandatory header section that contains metadata about the measurement sets contained. Metadata includes elements such as:

• Timestamp, indicating when the measurement began.
• Timestamp, indicating when the measurement finished.
• Different flags and tag entries.
• Pointers to other measurements that may be related, e.g., to the parent measurement data for interpreted data.

Figure 14.6-1 Relationship between the Measured Trace Set (blue) and the Interpreted Log (red).

The actual data (index of distance/length and the different measured or derived channels) are stored in WITSML objects called ChannelSets. For more information, refer to the WITSML_Tech_USAGE_Guide_v2.0_DoPRODML_c_v1.0.pdf document which can be found in the WITSML download in folder energyml\data\witsml\v2.0\doc, and see 2.4 PRODML Use of Other Energistics Domain Standards . The WITSML resources can be obtained by following the links at http://www.energistics.org/drilling-completions-interventions/witsml-standards/current-standards.

Examples of WITSML ChannelSets are shown in the next chapter, as part of the worked examples.

There are two types of DTS measurement data:

• Measured Traces: the “raw” measurement, indexed along the optical path distance, and as measured by the instrument box.

• Interpreted Logs: the “adjusted” (i.e., calibrated, re-sampled, smoothed, etc.) temperature indexed against the facility length of the physical facility (well, pipe, etc.) being measured. This may be considered the “product” of DTS measurement plus analysis/processing.

The mnemonics which are expected to be used for these two types of DTS measurements are as here:

Note that the index is mandatory for these types of data, but the other channels are not. In particular, the measurement trace set of mnemonics are suitable for either Raman- or Brillouin-type DTS systems, and any one system will certainly not generate all the measurement traces.

BUSINESS RULE: These mnemonics must be observed but are not enforced in the schemas.