oa Studying oil production allocation and well integrity by fingerprinting, biomarkers and isotopic ratios and studying the deconvolution of the commingled production

Fingerprinting studies of crude oil can solve many production allocation problems and well integrity issues that the operators can face in fields with commingled production. It can also be a very effective tool to know which portion of original hydrocarbon reserves has not yet been produced without interrupting the current production. In this paper, we will see the major role of the organic geochemistry techniques in solving these production allocation issues. In the Total Research Center Qatar (TRC-Q), we are using many techniques to help solve the production allocation problems. One of the most powerful techniques for this type of studies is high performance gas chromatography fingerprinting, which can discriminate the differences between oils from different reservoirs and different layers and can also help in discovering comingled production by analyzing the oil samples and comparing the most discriminated molecular ratios among all of the analyzed samples. The interpretation of these results will provide a very clear indication of the similarities and differences associated with the samples. Besides this technology, we are performing a further step: biomarkers studies to identify the origin (geological formation) of the crude oil. This technique compares oil samples based on the mass/charge ratios. These results are then interpreted to give a clear identification of the origin of the samples. Isotopic studies are significant part of what we are performing in TRC-Q. They give the most effective and precise results for discriminating different oils and identifying any concern regarding production allocation and well integrity. A great example that demonstrates all of the above mentioned analytical techniques is a study that TRC-Q performed in collaboration with Qatar Petroleum where all of the fingerprinting techniques have been used in a blind test to identify the source and origin of five unknown oil samples.