Domestic Sweet Monitoring Program

2015 - 2019


Data Requisition Template


Additives Subcommittee

2001 - 2004, 2018 - 2019


Phase II

COQA Additives Subcommittee Survey of Industry (AUG - OCT 2018)

COQA Additives Survey Announcement
Additive Survey


Phase I

The initial purpose of the Additive Discussion Group was to provide COQA members with a forum to discuss possible difficulties they have encountered with substances added to crude oil. 

The additive Subcommittee surveyed COQA members to determine the effects of additives in refining and pipeline situations.  Click on "Additive Survey" to see those results.

Additive Survey

Additives Subcommittee Notes


Asphaltene Precipitation

2015 - 2016



Asphaltene Precipitation Subcommitee Notes
Astor Crowne Plaza, New Orleans, October 21, 2015, 2pm-3pm

The meeting was roughly divided in to three sections.

1.        Examples of impacts:  BP quickly summarized what they have experienced regarding precipitated asphaltenes in domestic sweet (see presentation from June COQA meeting in Minneapolis for details).  A Marathon rep reported they had a coker furnace fouling event that may have been due to precipitated asphaltenes in domestic sweet; asphaltene issues were found in the crude feed but other issues may have contributed to the coker problem.  Valero, P66, Shell, Coffeyville Resources voiced that they have not heard of impacts at their refineries, any other refining companies present did not comment.

2.       Test Methods:  The conversation gradually shifted to test methods, possible causes of precipitated asphaltenes, and what they scope of the COQA should be.  Potential causes such as fine solids, upstream additives, and examples of precipitation in the Upstream were raised.  There were also suggestions that the COQA should work to recommend test methods and procedures to allow midstream blenders to blend crudes without compatibility problems.  Creating a compatibility for public use was deemed outside of the scope of this project.  No new test method options were offered or discussed in this meeting. 

3.       Next steps:  Hearing that no new, public test methods were being identified, but judging that there was interest to investigate the issue further, it was decided that a sampling and testing plan would be developed for sub-committee review.  Soluble Solutions was recommended as the testing company as they have a recognized test method and consulting service.  The suggestion is that once a fit for purpose test method at Soluble Solutions is identified and priced out, a small sampling plan will be developed by member companies who will then send in samples and pay for the analysis.  Results will be compiled by the COQA Director to provide an appropriately blinded final report for COQA use.  Conference calls will be used to finalize the plan and discuss the results prior to the next COQA meeting in March, 2016.



Canadian Crude Oil

2005 - 2006


Canadian crude oil is becoming ever more prevalent in the United Sates.  This subcommittee discusses the issues that are inherent in refining and shipping these crudes.

Canadian Crude Oil Quality Subcommittee Notes


Domestic Trading Centers

2005 - 2006


Mission Statement

We believe that crude oil designated as Domestic Sweet needs a few basic parameters in addition to gravity and sulfur in order for crude to fall within this designation.  These additional parameters are necessary to better define Domestic Sweet, while at the same time reducing its variability.  This will allow refiners to better determine the actual value of Domestic Sweet to them as they can with other, well defined crude types.

Additional parameters:

Nickel and Vanadium
Microcarbon Residue
Acid Number (TAN)
High Temperature Simulated Distillation (HTSD) yields
Recommended Additional Specifications for Domestic Sweet Crude Oil at Cushing, OK

On August 10, 2010, the following letter was sent to Cushing operators, shippers, and other interested parties with the COQA recommendations for additional specifications for Domestic Sweet Crude Oil at Cushing, OK

The Crude Oil Quality Association (COQA) is a petroleum industry technical organization comprised of members representing refiners, pipeline companies, terminal operators, chemical and service companies, and commercial laboratories.  The association is dedicated to the belief that maintaining the quality and integrity of the refining characteristics of crude oil streams is of importance to all parties from production to the refinery. As such, we have been addressing crude oil specifications for more than a decade. The Refiners Crude Oil Quality Group, predecessor of the COQA, was responsible for the successful adoption of the LLS specifications over 10 years ago.

Consistent with our mission and in studies spanning more than five years, COQA has identified key parameters that more comprehensively describe Domestic Sweet crude oil delivered at Cushing, OK (NYMEX: Light Sweet Crude Oil Futures), has defined the analytical test procedures to be used in measuring these parameters, has reviewed historical and current quality data for these, and recently reached consensus on the additional specifications shown in the following table.

These additional specifications will provide greater confidence in the quality of Domestic Sweet for all who physically process this grade, as well as those who transact futures and delivery contracts.  With this more comprehensive definition of the quality of Domestic Sweet, there will be a higher level of reliability and fungibility of this very important benchmark crude oil.

As part of the detailed statistical review of the data supporting these recommended additional specifications, the COQA, to the best of its knowledge and consistent with its Antitrust Guidelines, anticipates that adoption of these additional specifications will not restrict trade nor be a barrier to free and open competition in the markets.

The COQA recommends the immediate adoption of these specifications as part of the NYMEX Light Sweet Crude Oil Futures Grade and Quality Specifications (Section 200.12) (A), and in the operating procedures of the pipeline and terminal facilities at Cushing. The existing quality specifications for sulfur, gravity, viscosity, Reid vapor pressure (RVP), basic sediment and water (BS&W, S&W), and pour point as detailed in section 200.12 (A) (2-7) of the NYMEX Rulebook are to be retained.    

With our broad industry representation, experience, and expertise, the COQA is able and willing to provide support to you in the adoption of these recommended expanded specifications. The COQA remains committed to positive actions that promote and maintain the integrity of crude oil streams.  

I thank you for your consideration of these recommendations, and look forward to your response regarding when and how you plan to adopt and implement them.

Harry N. Giles
Executive Director

Recommended Additional Specification for Domestic Sweet Crude Oil at Cushing, OK:

Micro Method Carbon Residue: 2.40% or less by mass; as determined by ASTM Standard D4530-07, or its latest revision;
Total Acid Number (TAN): 0.28 mg KOH/g or less as determined by the first inflection point; using ASTM Standard D664-09a, or its latest revision;
Nickel: 8 parts per million (ppm) or less by mass; as determined by ASTM Standard D5708-05,Test Method B, or its latest revision;
Vanadium: 15 ppm or less by mass; as determined by ASTM Standard D5708-05, Test Method B, or its latest revision;
Light Ends <220°F by HTSD: Not more than 19 % by mass; as determined by ASTM Standard D7169-05, or its latest revision;
50 % Point by HTSD: 470°F- 570°F; as determined by ASTM Standard D7169-05, or its latest revision;
Vacuum Residuum >1020°F by HTSD: Not more than 16 % by mass; as determined by ASTM Standard D7169-05, or its latest revision.

Domestic Trading Centers Subcommittee Notes





The Education Forum was established to produce a training module for use by COQA members in enlightening  and updating non-quality professionals in the Petroleum industry on crude oil quality.  Three education forums will be available, one designed specifically for those in the pipeline area, one for non-technical (management and trading) personnel and one for refiners.

Pipeline Presentation

Refining Presentation

Presentation for Non-technical Professionals

The COQA is compiling a listing of Crude Oil Quality Incidents. They will be used for education and information only. Mitigation, cost, underlying causes are discussed.  The Incident Tracking Master is available to all.  

Incident Master

Our thanks to the American Petroleum Institute for granting us permission to make available the  following paper "Protecting Crude Petroleum Quality: A Report of the API Ad Hoc Crude Oil Quality Task Force".  Please do not reproduce this paper, or any part of it.

API Crude Quality TF





The Trading Sub-Committee was established as a forum for discussion on the feasibility of incorporating quality criteria in crude oil contracts.

Click on the date below to view committee notes.

Trading Subcommittee Notes


Water Measurement

2001 - 2004


The COQA established a subcommittee of members who are experts in the field of water measurement in crude oil.  The purpose of that group was to outline various methods available to measure water in crude oil and present the pros & cons of each measurement type.

The water measurement subcommittee was reconvened in May of 2001.  The new charter is to determine how the COQA can help move the industry toward "Best Practice" in water measurement.

Click on the date below to view the latest meeting notes and the Final Discussion Paper (contact the COQA Director for the Appendix).

Water Measurement Subcommittee Notes



1998 - 2002


The Mid-Continent Subcommittee was established to determine a "footprint" of quality for West Texas Sweet and West Texas Sour common stream crudes.  Much analysis has been completed and recommendations on specifications for these two crudes have been set.  The recommended specifications encompass gravity, sulfur, metals and distillation points.

Mid-Continent Subcommittee Notes


Round Robin

1998 - 2002


The COQA Crude Oil Round Robin was discontinued when the ASTM cross check program was instituted. All COQA participants were encouraged to join the ASTM program and continue their efforts in establishing quality controls for crude measurement and testing.

The COQA Round Robin ran from October, 1998 through May, 2002.  Eleven  successful rounds were completed, with 30 to 40 labs participating each time.  API gravity, vapor pressure, sulfur, salt, S&W, water by Karl Fischer, Carbon Residue, Nitrogen, Vanadium, Nickel, Pour Point and HTSD were the parameters included.  HLS, LLS, Cusiana,  Lloydminster  , Oriente and Olmeca crudes were tested.  



The Capline Subcommittee was disbanded after the implementation of Light Louisiana Sweet specifications on the Capline pipeline system. The Light Louisiana Sweet common stream on the Capline transportation system has specifications encompassing API gravity, sulfur, vanadium and nickel, microcarbon residue and distillation points. To the best of our knowledge, this is the first time common stream crude oil specifications have ever embraced parameters in addition to sulfur and gravity. An enforcement policy is in place to ensure the LLS specifications are met.