Compositional Variations between Precipitated and Organic Solid Deposition Control (OSDC) Asphaltenes and the Effect of Inhibitors on Deposition by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry

Abstract

Organic solid deposition control (OSDC) is a live oil test capable of simulating the production conditions of oil streams and can generate asphaltene deposits under production system conditions. OSDC can also simulate gas lift conditions because the producers are looking for artificial lift methods to produce oil from low-energy reservoirs. In this paper, we present the first compositional study on the OSDC deposits under gas lift conditions and compare it to C7 asphaltenes from the same crude oil precipitated in the laboratory, by use of ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry. Furthermore, deposits collected from chemically treated fluids were also studied. The negative-ion mass spectra of OSDC deposits from untreated crude oil and asphaltene inhibitor (AI)-treated crude oil are richer in acidic species, such as the O x and S x O y polar classes, relative to the parent crude oil. The molecular-weight differences for treated deposits relative to the untreated sample may help explain the deposition tendency in the tests. We infer that a correlation of field asphaltene deposition tendency with laboratory screening tests is essential for the advancement of asphaltene research.

Review of the Current Laboratory Methods To Select Asphaltene Inhibitors

“…In other studies, it was shown that the addition of asphaltene inhibitors did not necessarily prevent or reduce the deposition. However, in some cases, it worsened the problem. ,,− …”

“…Although dispersion tests have been widely used as fast screening methods for asphaltene inhibitors, there is no proven correlation between the dispersive efficiency and the prevention of asphaltene deposition on metallic surfaces. ,,, According to Vargas et al, the aggregation and deposition of particles to the surface are two competing phenomena. Thus, reducing the aggregation of asphaltene particles might facilitate the deposition process under certain conditions.…”

“…96 The OSDC test could also be used to evaluate the effectiveness of asphaltene inhibitors in reducing the deposition in live oil conditions. For example, in the study by Juyal et al, 56 two commercial asphaltene inhibitors were assessed using an OSDC setup. Interestingly, both inhibitors increased the deposition by 17 and 99%, with respect to the blank test.…”

“…Interestingly, both inhibitors increased the deposition by 17 and 99%, with respect to the blank test. 56 Akbarzadeh et al 97 reported a limited amount of asphaltene deposition from batch OSDC experiments, leading to high uncertainty in the measured data. In the batch tests, the number of available asphaltene particles for deposition decreases over time.…”

Developments in FT‐ICR MS instrumentation, ionization techniques, and data interpretation methods for petroleomics

“…Liu et al () oxidized sulfides in petroleum and identified them using (+)‐ESI FT‐ICR MS (Liu et al, ). ESI is one of the major ionization techniques used to study crude oils and there have been a number of publications using this technique for oil analyses (Zhan & Fenn, ; Hughey et al, ; Qian et al, 2001a,b; Hughey, Rodgers, & Marshall, ; Barrow et al, 2003, 2009; Hemmingsen et al, ; Klein et al, ; Mullins et al, ; Stanford et al, 2006, 2007a,b; Teräväinen et al, ; Headley et al, ; Panda et al, ; Schaub et al, ; Mapolelo et al, ; Miyabayashi et al, ; Smith et al, 2008a,b; Da Campo et al, ; Juyal et al, 2009, 2010; Shi et al, 2009, 2010a,b; Liu et al, ; Zhang et al, 2010, 2011; Zhu et al, ; Li et al, ; Chen et al, ; Gaspar et al, ; Jin, Kim, & Birdwell, ).…”