Traditional proppant placement evaluation in hydraulically induced fractures utilize detection of radioactive (R/A) tracers such as iridium 192, scandium 46 and antimony 124, which are manufactured in nuclear reactors, and then shipped to the wellsite and pumped downhole with the frac slurry. Although this technique has proven useful, it involves environmental, safety, and regulatory concerns/issues. Recently a new technology has become available that offers a viable alternative to radioactive tracers. Field examples of the application of this technology and its usefulness to the operator are presented in this paper, along with a field comparison to the results from R/A tracers.
The new technology utilizes a non-radioactive ceramic proppant (CEP) that contains a high thermal neutron capture compound (HTNCC). This high thermal neutron capture compound is inseparably incorporated into each ceramic proppant grain during manufacturing in sufficiently low concentration so as not to affect proppant properties. The non-radioactive proppant is detected using standard compensated neutron and/or pulsed neutron tools, with detection based on the high thermal neutron absorptive properties of the proppant relative to downhole constituents.
Multiple zones in two wells in Wyoming were hydraulically fractured utilizing the non-radioactive detectable ceramic proppant. In addition, multiple zones in a well in Utah were fractured utilizing the non-radioactive detectable proppant and the results are compared to results from an R/A tracer utilized in another well in the same field. These field results and comparisons will aid the frac engineer in choosing appropriate proppant detection techniques.
Author(s): Abram D. Grae; Shell Western E & P., Robert J. Duenckel; Carbo Ceramics Inc., Jordan R. Nelson; El Paso Corporation, Harry D Smith; Consultant, XIaogang Han; CARBO Ceramics, Terry T Palisch; CARBO Ceramics Inc.
Paper Number: SPE 139875