The IADC-RIM Downhole Telemetry Subcommittee is composed of members representing eight major oil companies, nine service companies, and one drilling contractor. The group has been meeting since January, 1985, in an attempt to bring a degree of standardization to the Measurement While Drilling industry in the areas of log format, correction charts, definitions of pertinent terms, and to present interim standards for specifying MWD - Communication - Channel - Performance as affected by variables such as depth, temperature, mud properties, noise, etc. The final objective is to provide information to the end users (drilling engineers, geologist, petrophysicists, etc.) that will enhance an objective understanding of MWD performance for evaluation and comparison of the products offered by the various MWD companies. The Subcommittee is presently divided into four groups:
Log Presentation Standards,
Drilling Parameter Influences on MWD Tools,) Standardized Tool Reliability Statistics, and) Specifications of Telemetry Systems.
This paper is presented in four segments that reflect the findings and/or the recommendation of the four work groups, respectively.
The MWD log format subcommittee has developed a tentative format for presenting MWD log measurements, surface derived drilling parameters, and directional survey data. The log for-mat has been divided into seven basic parts: Header, Run Data, Remarks/Disclaimer, Logged Data and Scales, Calibration Record, Bottom Hole Assembly Record, and Log Tail. While the sections of the log generally conform with the standard wireline format prescribed by API, SPWLA, etc., special consideration has been given to the nature and unique requirements of MWD, and surface derived data. The results of this project have been aimed at establishing an industry standard to facilitate the use of this information in comparing one log to another.
Several companies currently provide MWD services to the oil industry; at this time, no two of these MWD companies display their measured data or computed parameters in the same format. In fact, the formats employed vary from region to region, and even from well to well.
Of the several projects being pursued by IADC-RIM subcommittees, one specific goal assigned was to devise a reasonable standard to serve as a basis for future data presentation; the following material represents, we believe, a rational approach to standardization, which is based on no one company's current for-mat, yet is based on the most appealing aspects of each, and on the necessity of handling some rather unique data sets.
The criteria purused in designing the format presented below are:
The MWD format should emulate wireline data displays, whenever possible as outlined in API recommended standards RP31 (API 1967), PP33 (API 1974) and SPWLA Hydrocarbon Well Logging Practices.
These standards and recommendations should be adhered to as reasonably as possible with regards to for-mat content, size, scales, etc.