Abstract:

Partition coefficients between oil and saltwater of water soluble oil constituents (such as BTEX and phenols) were measured at high pressure (up to 15.5MPa) and low temperature (4C). Parameters, such as pressure, temperature and salinity were varied to determine result sensitivity and to mimic conditions varying from seafloor to the surface at the MC252 spill site. Sensitivity to ‘live’ oil characteristics were investigated by charging the oil sample with methane at varying pressures.

Suggested Citation:

Thomas Oldenburg, Ryan Snowden. 2015. Water/oil partitioning of water soluble oil constituents at diverse temperature and pressure conditions. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7D21VK5

Purpose:

Experimentally determined equilibrium concentrations of water soluble components of oil allows increased accuracy in simulation of mass balance and toxic effects of those components.

Data Parameters and Units:

The following is a list of data parameters and units of measurement for each sheet in the Physical Property Summary dataset. Density Viscosity Sheet – Viscosity and density of several containers of each sample measured at 1 atm and 20°C. Densities are also extrapolated to other temperatures: Sample ID [Source Oil A (SOA), Source Oil B (SOB), Surrogate], Measured Oil Viscosity at 20°C (cP), Measured Temp (C), Oil Density (g/cm3), API Gravity; Settling Times Sheet – Oil and deionized water at various proportions were mixed and then allowed to settle. The percentage of water that was separated (not in an emulsion) was measured over several hours at different temperatures: Water/Oil Ratio [(50/50, 60/40, 90/10) measured at (6°C, 12°C, 25°C, 35°C)], Time (min), Surrogate Oil (%), Standard Oil B (%); Volatile Mass Sheet – Three samples of each oil type were placed in open shallow containers at 22C and 10% relative humidity. The loss of mass due to volatile evaporation was then measured over several days. Average mass and standard deviation of each set are given: Sample (SOA, SOB, Surrogate), Mean Time Elapsed (h, Standard Deviation), Mean Mass (g, Standard Deviation), Mean Loss (%, Standard Deviation); Water Content Sheet – Karl Fisher titration (ASTM D1744) was used to find the percentage of water in each sample: Sample ID (SOA, SOB, Surrogate), Percentage of water in each sample (wt/wt%), Mean wt/wt% (per sample type), Standard Deviation (per sample type), N (per sample type); The following is a list of data parameters and units of measurement for each sheet in the Oil Volatility Experiments dataset. Recalculated Sheet – Contents of this sheet are the data used to generate the results for the Volatile Mass sheet in the Physical Property Summary dataset: Date (DD-Month-YY), Sample (START, SOA, SOB, Surrogate), PRG 3 (12678, 12721, 12733), Time (hh:mm), Time Elapsed (hhh:mm), h, m, Total (h), Replicate (1, 2, 3), Mass (g), Mean Time Elapsed (h, Standard Deviation), Mean Time Elapsed (d, Standard Deviation), Mean Mass (g, Standard Deviation), Mean Loss (%, Standard Deviation); Environmental Data Sheet – Contents of this sheet contain the environmental data collected while the oil volatility experiments were being conducted: EasyLog (Log Sequece), USB (Date in DD-Month-YY format), Time (hh:mm), Time Elapsed (h), h, m, Total (h), Total (d), Celsius(ｰC), Humidity(%rh), Dew Point(ｰC);

Methods:

The following are descriptions about the oils used in the analyses. Source Oil A (SOA): Collected from MC252 by the vessel Enterprise Discoverer on May 20th 2010 via riser insertion tube. Stored in 1L bottles while onboard, then refrigerated on shore; Source Oil B (SOB): Collected from MC252 by Enterprise Discoverer May 22nd and 23rd 2010 via riser insertion tube. Stored in 4L bottles and 55 gallon drums onboard, then refrigerated on shore; Surrogate: Louisiana Light Sweet Crude Oil; A high pressure partitioning device has been constructed to mix and separate oil and water under a range of precisely controlled pressures and temperatures. Once separated, both portions are analyzed with GC-MS and GC-FID to determine the concentrations of oil components in both fractions.

Instruments:

Custom built high pressure partitioning device using two HPLC pumps, recirculating chiller and a high pressure hydro-pneumatic accumulator GC-MS and GC-FID: Agilent GC 6890N with 7683B Autosampler, Agilent MS 5973B inert.

Error Analysis:

All samples will be analyzed multiple times at each parameter set to estimate precision.

Individual Files: