Multifaceted Solution of Analytical Challenges in Complex Oilfield Materials With Synchrotron Techniques

Abstract

Summary The versatility of synchrotron techniques for the solution of oilfield questions is illustrated by the application of powder X-ray diffraction (PXRD) and X-ray absorption near-edge structure (XANES) spectroscopy to a toluene-insoluble oilfield-residue sample from an alkaline/surfactant/polymer (ASP) -flood site in Taber, Alberta, Canada. The primary questions regarding the sample were the sources of the barium and nitrogen (both at levels of approximately 0.8 wt%). Synchrotron PXRD provided better signal–noise and detection limits than previously obtained laboratory PXRD data, enabling the identification of four additional crystalline minerals including heulandite, (Ba, Ca, Sr, K, Na)5 Al9 Si27 O72 (H2O)22, a tecto-silicate zeolite known for accommodation of a wide variety of cations. Heulandite provides a plausible location for barium (and strontium) observed with chemical analysis. Synchrotron XANES spectra at the nitrogen K-edge suggested that the source of the nitrogen content was a corrosion inhibitor, rather than a polyacrylamide (PAM) -based compound, as originally assumed.