Terralog provided Cuttings Re-Injection (CRI) support services to AKROS for the offshore Prirazlomnaya oilfield in the Pechora Sea. The CRI process was used to dispose of various E&P waste streams such as drilling mud, drill cuttings, other drilling wastes, cement returns, displacement fluid, waste water, and produced water. The subsurface technical engineering support for this project included the following services:
- Process control for CRI operations
- Maintaining formation injectivity
- Ensuring waste material containment in the disposal zone
- Ensuring well integrity
- Maximizing formation storage capacity
- Injection strategy design and evaluation
- Analyses of injection data to optimize injection strategy and CRI well performance
- Daily, weekly, and monthly reports, including operational recommendations
In addition, Terralog also developed an innovative Discrete Element Method (DEM) numerical modelling approach to simulate complex deep well disposal operations for this project. The model can be calibrated to field data (from injection operations) and used as a diagnostic tool to assess formation and overburden response to long-term, sustained, large volume, cyclic deep well disposal operations. The objectives of this DEM work can be summarized as follows:
- Characterize formation fluid flow systems and fabric heterogeneities
- Determine the development of stress, pressure, and displacement gradients
- Assess hydro-mechanical coupling behavior of the formation and overburden
- Determine the size/geometry of the stimulated zone and how far the fracture events will propagate under different injection conditions
- Assess fluid flow direction and inflow/outflow rates in different flow systems
- Assess and optimize slurry design and optimization of multiple injection cycles and batch sizes
The DEM approach provided a significantly improved ability to assess and characterize formation response to sophisticated deep well disposal processes.