Chemostatistic allocation of shale oil production using acidic NOS compounds determined by negative-ion electrospray Fourier transform ion cyclotron resonance mass spectrometry
Nitrogen-, oxygen-, and sulfur-containing (NOS) heterocompounds have differing mobility to migration. Neither the ratio nor concentration of heterocompounds can be readily used to quantify the extent to which the oils have been commingled. In this paper, we introduce a new allocation technique for optimizing the development of unconventional shale reservoirs using heterocompounds determined by electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). A total of 2 oils and 5 mixtures prepared in laboratory, 4 oils and 2 bitumens extracted from the Vaca Muerta shale oil play, 5 oils and 15 bitumens extracted from the Niobrara shale oil play were used to test and illustrate if and how the newly developed chemostatistic allocation technique works. The results of chemostatistic devolution show good match to those of geochemical observations. In particular, fractionation effects were shown extensive and widespread with heterocompounds in the Niobrara shale oil play. Nevertheless, the chemostatistic allocation method still determined that oils were mainly produced from the previously suggested reservoirs (i.e., A- & B- chalks) based on SARA fractions, n-alkanes, C27-28-29 diasteranes, pristane and phytane. The chemostatistic method is capable to de-convolute fractionated oils directly from residual bitumens. We are unaware of any previous research has achieved that. This newly developed allocation technique can assist to determine a rapid developing of multiple-stacked shale oil reservoirs. Allocating the commingled oil production from a conventional well is another potential application.
AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019