Abstract

In 2006 and 2007, MPI acquired over 100,000 acres of land in Howard and Glasscock Counties on which to develop prospects for re-entry or new drilling for hydrocarbons. The main focus of the prospects was the “Wolfberry play”, which is the combination of the Spraberry and Wolfcamp formations. In order to exploit the acreage position, a log analysis template was needed to: 1) evaluate the open-hole logs available on the existing wells for possible re-entry, and 2) provide a guideline that could be applied in evaluating new drill areas. The data base of existing wire line logs ranged from open hole vintage logs to modern products that included triple combos, array sonic, spectral gamma, and micro-imaging logs. Therefore, a log analysis template needed to be sufficiently flexible to accommodate the wide range of wireline log suites but provide one common platform that would allow comparable evaluation of the results. That is to say, we needed to be confident that the “pay zones” identified from a vintage logging suite from the 1950s’ would be as credible as the results derived from a modern day logging suite. In addition to the variations in logging suites, each of the formations encountered in the wellbore have rock properties that are unique to analyze for hydrocarbons. To accommodate the various types of logs and formation parameters, a log analysis template was designed using commercial log analysis software. The template utilizes the standard Archie calculations combined with techniques to identify the presence of fractures, organic-rich shales, and porosity/resistivity anomalies that indicate the presence of hydrocarbons. Thus, the log presentation becomes the definitive product for evaluating the well data. The “pay zones” identified by this template have provided a means to the successful exploitation of properties acquired by MPI.