Presentation on Reservoir Souring at ADIPEC

We are happy to announce that we will be presenting a paper on Reservoir Souring at ADIPEC next week.

SPE-197616-MS Paper

Title: A Novel Quantitative and Predictive Reservoir-Souring Approach to Assess Reservoir Souring During Planned-Waterflood Development Plan

Authors: H. Salimi, M. Namdar Zanganeh, S. McCarthy, L. Pirlea, PanTerra Geoconsultants BV; H. Balushi, M. Lawati, M.K. Yarabi, Petroleum Development Oman

Scheduled for Tuesday 12 November, at 10:30 in Capital Suite 2 (HSE: Innovation in HSE Management)

Souring potentials of fields during planned-waterflood development need to be investigated to enable the selection of the injection-water source and facility-design options. This paper presents the application of a novel reservoir-souring approach to assess the souring potential of a Middle-East field that is associated with three potential injection-water sources in terms of souring, to recommend ways to prevent or reduce H2S production, and to determine the optimum solution for injection water.

The novel approach includes:

  • fluid sampling and analysis,
  • a desktop study,
  • a dynamic-reservoir simulation, and a surface-facility evaluation.

 

In the desktop study, a qualitative assessment of souring associated with the three potential injection-water sources (shallow-aquifer water, produced water, and mixtures of produced and shallow water) and mitigation strategies to limit future H2S concentrations were carried out.

Subsequently, a compositional non-isothermal dynamic model that includes 3 phases, 18 components, and 18 reactions was developed to quantitatively predict the most-likely and the worst-case H2S levels over the field’s life. Several sensitivity runs were performed to assess the impact of the key uncertain parameters on the H2S level.

The results indicate that re-injection of produced water (deep aquifer) with a salinity of 173,000 mg/l not only has a very low souring risk, but also offers the most manageable conditions in terms of scaling and corrosion control for both the reservoir and the facilities. For this water, the simulated earliest H2S-breakthrough time is year 2038 and the H2S concentration in the gas phase will not exceed 1000 ppmv until 2074.

On the other hand, injection of the shallow-aquifer water with a salinity of 11,000 mg/l has a high risk of souring. The simulated earliest H2S-breakthrough time is 2025 and after breakthrough within one year the gas-phase H2S concentration reaches 1,500 ppmv at ambient conditions.