National Instrument 51-101 (NI 51-101) Reserves Reconciliation-Part 2, A Review of Technical Revisions In Annual Information Form Filings For End 2003
Authors: Robinson J. Glenn , Elliott David 
Published: March 2010

Introduction
One of the requirements of National Instrument 51–101, Standards of Disclosure for Oil and Gas Activities, is the submission of Form 51–101F1, Statement of Reserves Data and Other Oil and Gas Information, at a date that coincides with the end of a company's financial year. For the majority of companies, this is December 31. Part 4 of Form 51-101F1 is the requirement for a reconciliation of reserves between reporting periods. This was described and discussed in Part 1 of this paper, in the November 2004 issue of the JCPT. One of the most important elements of this reconciliation is the technical revisions. This paper continues the discussion of technical revisions and reports on the analysis of the technical revisions reported in filings at the year-end of 2003.
Technical revisions are changes in reserves for properties contained in the opening balance and which are still owned at the end of the reconciliation period. The revisions occur mainly as the result of poor evaluation practices and of new technical information that was not known at the start of the reconciliation period. 238 companies submitted National Instrument 51–101 F1 Statements with reconciliation tables containing technical revisions for the period December 31, 2002 to December 31, 2003. 216 companies were in the database at the time of the analysis here, although not all companies had reserves for all product groups. This data is available on the SEDAR Web site (www.sedar.com).
Technical revisions are intended to be "pure" revisions to volumes in the opening balance. However, due to a misunderstanding of the requirements in this first year for NI 51–101, some filers included infill drilling and technical revisions for acquisitions made during the year. The data discussed here contains some corrections for these items.
A number of companies have been excluded from the analysis. These were:14 companies that have exemptions that allow them to report using SEC/FASB requirements. The "Changes in the Net Quantities of an Enterprise's Proved Reserves of Oil and Gas During the Year, Revisions of Previous Estimates," of the SEC/FASB system is not a "pure" technical revision since it contains other factors, such as development drilling and economic factors, and cannot be used for the type of analysis carried out here;A small number of companies that had not filed at the time of the analysis or had unresolved questions in their reserves numbers. Their omission has no significant effect on the general results; and,23% of the companies in the analysis had no reserves at December 31, 2002, and hence no technical revisions.
Although the authors are employees of the ASC, the views expressed in this series of articles do not necessarily represent those of the ASC, CSA, SPEE, or the Petroleum Society.

The Analysis of Technical Revisions
The discussion contained in Part 1 of this paper on criteria for technical revisions is continued here. All of the data analyzed is for reported reserves, which must satisfy the following criteria: