by rockdoc123 » Fri 08 Jul 2016, 19:16:43
Rockman I have worked for numerous companies from multi-national to small independent in size. I think your description might be true of some of the small private companies but I can tell you it would not fly in any of the companies I worked for. In most of those companies we created reserves sheets for wells and pools that highlighted what the calculated important variables in the reserve equation were...ie. thickness (measured from logs and interpolated with seismic), porosity (logs calibrated with core), area (seismic and well information), connate water saturation (log measurements) and formation volume factor (determined from PVT lab data). This data left very little room for argument and error around variables such as porosity height could always be calculated. That data is what the third party auditors saw along with the raw information which they would spot check. Before that information went to the external auditor it was signed off by the qualified internal reserve auditor. In many of the producing fields which are not subject to strong water drives material balance calculations are the gold standard, again error bars on the bottom hole static pressures can be used to narrow in the range. From your description it seems that the variability you speak of is not related to proven reserves but rather probable and possible. The SEC is generally only concerned about proven numbers and the need for companies to move probable to proven in a timely fashion. There is a recent crack down on PUDs.
$this->bbcode_second_pass_quote('', 'N')ot that's just the INTERNAL analysis. Now third party auditors: there's always a certain amount of fudging room. It's not entirely like negotiating when buying a new car. And sometimes a lot less ethical. LOL. Many years ago I presented a company's reserves to an auditor in Tulsa. That company also has an office at our home base in Houston. So why go to Tulsa? Because that office manager would be more "flexible" in their evaluation because his office was in greater need of that consulting fee.
Ever since Sarbanes Oxley external auditors have been legally responsible for their audited results. The SEC can go after them directly for false reporting. As a consequence the large reputable firms which I mentioned before will not "barter" they will listen to arguments but generally resort to definitions and guidelines as set out by the SEC and COGEH. Years ago you could get the auditors to accept your interpretations as long as they weren't wildly over the top, now these same firms are very rigid and generally err on the side of caution. Private companies as a rule do not tend to audit their reserves unless they have a plan within the next year to go public through an IPO or RTO. Public companies, on the other hand, are required each year to audit a certain amount of their reserves in rolling fashion year on year. I spent a lot of time prior to retiring reviewing the securities submissions of international independents of the intermediate to small size. Invariably all of them had submitted audited reserve reports with their 51-101 or SEC filings.
There is of course a certain amount of error with regard to reserves. This is reflected in the distribution of the reserve types. Proved producing reserves should have very little room for argument whereas the error bar around possible reserves could be significant. Whenever I calculated reserves and resources assessed to a pool or new discovery it was done with Monte Carlo which takes into account the uncertainties in the estimates. By assessing P10 to P90 distributions for each of the variables you end up with a probability distribution of reserves. On a field that has lots of wells and production history along with good data that distribution should be relatively tight about the mean. ON the other hand in a field that is a new discovery with limited data that distribution will be much broader. That distribution should be related with your more deterministic view of proven, probable and possible reserves.
The reserve issue does become more grey when addressing the unconventional shales. The accepted method is to generate a range of type curves for a particular formation that captures all information available at that point in time. The initial production decline is then matched against that range of decline curves to arrive at an EUR for the well. Each year the wells decline is checked against the range of curves to either prove or reject the initial estimate of EUR.