An operator in Eastern Europe faced the challenge of testing a heavy oil well in a high H2S environment situated at a UNESCO World Heritage site. The operator needed to find a solution that would ensure the goal of ultimately producing commercial, export-ready crude.
Because of the well’s close proximity to a communal area and its concentrations of 6% H2S and 2% CO2, operations were subject to strict emission limits. A proper solution held significant value for the operator as the results would determine the viability of its future operations in the country.
To fast-track the job, SLB deployed its Production ExPRESS™ rapid production response solutions, including an express EPF engineered with standard well test equipment, an emulsion treatment system, and a customized solids management system. The addition of Vx™ multiphase well testing technology enabled monitoring of the fluid H2S content in real time. After a three-phase separator was used to process the components, the gas was routed through a knockout drum and flared using a customized 60-m stack manufactured specifically for the purpose. The 60-m height enabled the EEPF to flare the gas without exceeding local regulations for SO2 dispersion, while reducing the impact on nearby communities.
Three vertical surge tanks were used as a second-stage separation process for the remaining oil and water. During the cleanup phase, scavenger was added, along with defoamers and demulsifiers, to reduce the H2S concentration. Afterward, during the extended well test phase, the contents were circulated through four horizontal tanks and passed through a nitrogen stripping column owned by the operator, to further reduce the H2S content through mass transfer.
Upon exiting the nitrogen stripping column, oil with <10 ppm of H2S and <10 psi Reid vapor pressure (RVP) was considered ready for truck transport to the crude terminal. The water was also trucked to a water treatment facility.
The use of an express EPF enabled production of more than 70,000 bbl of commercial crude oil export, yielding early cash flow. During the project, the solution handled nearly 4,000 bbl of water and 250 MMcf of gas while H2S levels were decreased to less than 15 ppm without HSE incidents. As a result, the project was a success and the data collected by Production ExPRESS solutions enabled the operator to continue its operations. It also helped to derisk the large upfront capital investment for the operator.
