Aligns with United Nations Sustainable Development Goal 13
Reduced 14,000 metric tons of CO2e by eliminating flaring
An operator in Western Kazakhstan manages a giant onshore carbonate gas condensate field that is known for fluids with high H2S content. Reservoir pressure declined over the life of the field, with high water content suppressing the natural flow and pipeline backpressure adding to production loss. This combination of factors posed increasing challenges for the operator when starting up wells after shutdown.
The candidate wells were naturally flowing wells, but due to high backpressure from the production line and the hydrostatic pressure created by settled water, the wells were unable to start up after shutdowns. Also, the presence of a gas cap in the well columns was challenging because of the undesirable effects of gas slugs.
Historically, the operator’s wells were started up using CT and nitrogen. However, this method had several drawbacks, including limits on the volume of nitrogen available at the wellsite. Due to the corrosive nature of the H2S-laden fluids, CT intervention required the use of anticorrosion inhibitors and chemical scavengers. Because these chemicals were not accepted by the local processing plants, the operator needed a solution that could be applied without negative effects in the processing stream.
To address these challenges, SLB worked closely with the operator's operations team to determine the best solution. After due consultation, SLB proposed a surface pressure boosting and well unloading solution, a key part of its Production Express™ rapid production response solutions portfolio. The surface pressure boosting package can achieve well unloading objectives without flaring of oil or gas, providing an ecologically sound solution.
The proposed solution consisted of surface well testing equipment and a Reda Multiphase HPS™ horizontal multistage surface pump. The presence of a gas cap in the well column had to be considered in the design phase to mitigate the undesirable effects of gas slugs. High gas volume fraction (GVF) was also considered to make sure there was enough capacity to boost the fluids and overcome production line backpressure. GVF was an important parameter to be monitored during the process, so the setup was equipped with a Vx Spectra™ surface multiphase flowmeter to precisely measure the GVF and well flow rates in real time to ensure the pump remained within the operational envelope.
The operator successfully started several wells using the well unloading package and saved from flaring a cumulative total of 57 MMcf of gas and 17,000 bbl of oil. Once a stable flow rate was achieved at the surface, the well unloading package was bypassed and the well continued producing through its own natural flow. At that point, the well unloading package was demobilized and used again at other wells.
Within weeks of first deployment, the successful application of the surface multiphase boosting solution helped KPO to quickly bring wells back into production without causing issues for the processing facilities. Based on the success of the pilot study and the outstanding collaboration by both teams, the operator will continue using Production Express solutions to start up its remaining idle wells.
