Ionic Modeling of Field Conditions: Improvements over Traditional Laboratory Approaches

Characterizing environmentally assisted cracking, including SSC, SCC, carbonate cracking, HIC etc., presents an ongoing challenge to the oil and gas industry. This presentation will review theoretical modeling and experimental methods to examine in-service performance windows, translation of in-service conditions to laboratory conditions and practical challenges for cracking specimens in the laboratory.

Traditional experimental setups have relied on rules of thumb and past experience to achieve certain target conditions in the lab that may or may not accurately represent the field conditions. Ionic modeling of solutions provides an accurate path to attain the target conditions needed by modeling the correct amounts of species. The differences between the traditional laboratory approaches and the implementation of lab tests based on an ionic modeling tool will be presented. In addition such modeling tools also provide a basis to accurately understand down-hole conditions in terms of in-situ pH and acid gas solubility based on surface or “open-cup” measurements. Another important application of ionic modeling tools lies in the characterization of operating conditions where known service conditions for cracking have been documented and defining these operating conditions based on the important variables for cracking.