oa Application of Transportable Sec-UV Analytical Technique for Geochemical Fingerprinting in a Middle-East Carbonate Field

This paper discusses the deployment of a SEC-UV transportable device to provide geochemical fingerprints for oil production allocation in a mature offshore field in Middle East. The objective was to identify production contributions from different reservoirs produced commingled and to detect anomalous contributions for wells completed in a single reservoir possibly originating from completion integrity problems. Oil samples from 30+ wells were collected and tagged to the 6 different reservoirs involved. These samples were fingerprinted using SEC-UV method recorded on the transportable device and GC-FID method, widely used in the oil industry. The fingerprinting results were submitted to statistical analysis. Both chemical fingerprinting techniques were able to evidence significant chemical differences between oils from the different reservoirs, allowing them to be used for production allocation purposes. The surface production sampled were analyzed and the relative contributions from the completed reservoirs were calculated to provide data for reservoir model history match of the field. Moreover, SEC-UV and GC-FID accurately identified some wells with unexpected surface production and allowed to identify the reservoirs from which they were producing. The undoubtedly identification of the unexpected contribution and their correct re-allocation to the proper reservoir zones clearly demonstrates the significant value of these technologies.