H2A Completes LNAPL Conceptual Site Model (LCSM) Updates for a Large-Scale Refinery
H2A’s J. Michael Hawthorne, PG, Shannon Walker, PE, and Si Xu, EIT, recently completed an extensive redesign of the LNAPL Conceptual Site Model (LCSM) for a large-scale oil refinery located in southeast Texas. The analysis included a detailed review of all gauging and well construction data, fluid physical properties, aquifer properties, multiple LNAPL recovery and recoverability analyses, and detailed stratigraphic analyses (CPT/ROST and boring log data). The data were captured in LCSM update reports that included various Diagnostic Gauge Plots, Advanced (CPT) Hydrostratigraphs, and Production Hydrostratigraphs, as well as other analyses and cross-references. An initial goal of the LCSM updates was to identify areas of confined or perched LNAPL that result in exaggerated apparent NAPL thicknesses (ANTs) in gauged wells. Once wells exhibiting confined or perched conditions were identified, the mobile LNAPL interval in the formation was determined to remove the exaggeration. Subsequent tasks are to include analytical modeling to evaluate LNAPL specific and recoverable specific volumes, calculation of LNAPL transmissivity for multiple recovery wells based on LNAPL recovery and operational data, and capture analysis modeling of the active site remediation systems.
