Stacked pay in unconventional plays has emerged as the primary focus for a majority of operators in North America. The number of completion targets range from two zones in the Bakken to more than ten zones in areas of the Permian Basin. Proper development of multi-zone reservoirs will yield the greatest recovery factor for the unit and minimize the drilling hazards and completion challenges related to depletion. Proper development maximizes the propped height while minimizing propped fracture overlap; this combination improves recovery without overcapitalizing the completion.
This paper will review existing and emerging diagnostic tools deployed in the STACK (Sooner Trend Anadarko Canadian and Kingfisher counties) to identify the number of landing intervals required to effectively drain the Meramec formation. The Meramec formation has produced a number of prolific wells from several benches contained within several hundred feet of reservoir.
The diagnostic tools that will be reviewed in this paper include electromagnetic (EM) proppant detection, radioactive (RA) proppant tracer surveys and offset pressure responses. The EM proppant and RA proppant surveys were used in a vertical well to measure the propped fracture height. The presence of the RA tracer is detected using a spectral gamma ray log; the EM proppant is mapped using a surface array of electric- and magnetic-field receivers. Downhole gauges in a vertical well measured the pressure responses generated during the treatment of an offsetting horizontal well to evaluate the effects of fluid viscosity on fracture height. Results from the diagnostic tools have been integrated into the well spacing strategy for upcoming development units.