Improved Selection of Candidates for Stimulation Treatment in the Wilcox Play in the South Texas/Mexico Border Area

摘要

A particular South Texas gas field has suffered severe production decline in the last two years. The wells were completed in the Wilcox foemation, which extends from the Burgos Basin in Mexico through Texas into Louisiana. The object was to identify and treat potential producing zones in all existing wells to increase production. Hydraulic fracturing is the preferred stimulation technique in these formations. Typically multiple zones are fractured in each of the wells. The stimulation treatments are designed with the aid of 3D hydraulic fracture models. Wireline logs provide the most comprehensive and continuous input parameters in such modeling for borehole stress profile, permeability index, elastic moduli, lithology, porosity and fluid saturation's. Existing open-hole wireline logging data were reprocessed using a new technique which provides all the available logging data in a format suitable for direct input in 3D hydraulic fracture models. An automatic aoning technique divides the data into consistent intervals based on stress contrast. The representative design parameters are then computed for each zone. The outputs are a blocked stress profile and a set of zone. The outputs are a blocked stress profile and a set of zoned fracture design parameters. This new technique was used to evaluate all the stimulation candidates in the field. One well was bypassed for treatment altogether, saving