Technology for Monitoring Gas and Water Breakthrough Intervals using Chromate Desorption Systems in the Development of Fields in the Caspian Sea

The paper presents a novel technology for determining the intervals of gas and water breakthrough in the development of fields on the Russian shelf of the Caspian Sea. The proposed technology is similar to traditional production logging and monitoring of horizontal wells using fiber optic systems. The technology aimed at determining the phase components is based on chromate desorption systems (CDS) with individual selective analytes used. CDS are installed on the lower well completion equipment (sand filters, inflow control devices, multistage hydraulic fracturing equipment and so on) and have a unique combination of pairs of oil-, water- and gas-soluble analytes for each interval. From the CDS, an analyte begins to release when in contact with a target fluid to surface with this fluid. At the wellhead, samples are taken according to a specific program, then laboratory analysis by chromatographic methods and mathematical interpretation of the composition of the inflow are performed. The paper presents an example of work when the intervals of gas outs were determined directly in the field using a micro-chromatograph.