The OilUmixer software is a sophisticated tool to use oil geochemistry to determine the contribution of individual production streams to a commingled production stream.

At OilTracers®, we allocate production from multiple zones (2-8 zones) by processing geochemical data using OilUnmixer™, a proprietary Weatherford Laboratories software package. OilUnmixer™ is part of the Weatherford ChromEdge Suite software package.

In brief, production allocation is achieved by identifying chemical differences between "end-member" oils (samples of oil from each of the zones or production streams being commingled). Parameters reflecting these compositional differences are then measured in the end-member oils and in the commingled oil. The data are then used to mathematically express the composition of the commingled oil in terms of contributions from the respective end-member oils.


Our software package (OilUnmixer™ v 4.0) is more sophisticated than the McCaffrey et al. (1996, 2011) approach in that our current software package utilizes more advanced methods for:

  1. dealing with analytical uncertainty,
  1. assessing the validity of end member (zone specific) calibration samples,
  1. finding and mathematically removing contamination in the end members or commingled oils, and
  1. "testing" the validity of the allocation results (in a graphical, easy to understand form).

The mathematics of  production allocation involves the simultaneous solution of hundreds of linear mixing equations (based on the abundances hundreds of compounds in the commingled oils and end member oils). Therefore, software is the ideal tool to perform these calculations, and we have created the OilUnmixer™, part of the Weatherford ChromEdge Suite, to automate that task.

OilUnmixer™ is a software package developed by OilTracers® to geochemically allocate commingled oil production from 2-8 commingled pay zones.

OilUnmixer™ software for allocation of commingled production has been subjected to numerous blind tests by numerous petroleum companies. A blind test is when an outside laboratory prepares artificial mixes of multiple oils, and then OilUnmixer™ software is used by OilTracers® to determine the contribution of each oil to the mixes (with OilTracers® having no advance knowledge of what the "answer" is). Numerous blind tests have shown that OilUnmixer™ typically yields allocation results that are within 1-5% of the actual result, even when the oils being commingled are extremely similar in composition (McCaffrey et a., 2011, 2012).  Learn more about the science of Production Allocation here.


McCaffrey, M. A., D. K. Baskin, B. A. Patterson, D. H. Ohms., C. Stone, D. Reisdorf (2012) Oil fingerprinting dramatically reduces production allocation costs. World Oil, March 2012, p 55-59.
McCaffrey, M. A., D. H. Ohms., M. Werner, C. Stone, D. K. Baskin, and B. A. Patterson (2011) Geochemical allocation of commingled oil production or commingled gas production. Society of Petroleum Engineers Paper Number 144618. p 1-19.
McCaffrey M. A., Legarre H. A. and Johnson S. J. (1996). Using biomarkers to improve heavy oil reservoir management: An example from the Cymric field, Kern County, California. American Association of Petroleum Geologists Bulletin 80(6), 904-919.

Geochemical techniques for allocating commingled production from multiple zones in a single well typically result in a >95% cost savings relative to production logging, making this software a very cost effective tool in the production realm.