Fluid Preconditioning, Northern Iraq | SLB

Mobile well testing and nitrogen stripping solution lowered H2S by 92% while boosting production in Iraq

Middle East, Iraq, Asia, Onshore

Production ExPRESSTM rapid production response solutions produced 3,700 bbl/d of oil and >500 Mcf/d of gas during the year it was deployed. A mobile nitrogen stripping column was used as a part of standard well testing setup to bring the high H2S under control.

A Middle East operator with extensive E&P assets in northern Iraq encountered a challenge when trying to incorporate new wells into the local production stream. The wells presented obstacles because of their high H2S concentration (4% to 14%). As a result, it was necessary to treat the effluent to obtain a crude compatible with the production facility, which required an export-ready light crude with low H2S content.

To address the challenge, SLB applied its expertise in fluid preconditioning and express early production, both part of its Production ExPRESS solutions portfolio. Solving the production facility requirements was made possible by flowing oil from a nearby well pad to dilute the viscosity, as well as utilizing a nitrogen stripping column to decrease the overall H2S content of the merged flow and make it ready for export.

After passing the choke manifold, the well’s effluent was subjected to a two-stage separation process using well testing separators. Before entering the separator, the fluids were heated to increase the separation efficiency and also reduce the H2S concentration of the oil.

Once the three phases were separated, the oil stream was sent to the stripping column to decrease the H2S content using a mass-transfer process. Next, the oil was treated with H2S scavenger and stored in a set of six atmospheric 500 bbl tanks for later export to the production facility using two centrifugal pumps. Gas from the separation process flowed through knockout drums to separate any remaining liquid prior to being flared.

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This view shows several of the fluid preconditioning components installed at the Iraq wellsite, including a separator, indirect heater, knockout drum, and flare stack.

Once installed, the solution enabled production for an entire year until project completion. The express EPF produced a total 3,700 bbl/d of oil and >500 Mcf/d of gas while use of the nitrogen stripping column decreased H2S content from more than 500 ppm to ~40 ppm. The next step will be an advanced solution that adds a gas incinerator (for green completion) with the gas reinjected into the pipeline.

Products Used