Unlocking the Potential of Croatia’s Panonian Basin Reservoirs with Nuclear Magnetic Resonance
M. Kozlowski, D. Parlov and Z. Čogelja
Event name: 80th EAGE Conference and Exhibition 2018
Session: Petrophysics I
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 810.13Kb )
Price: € 20
Intensive oil and gas production in Croatia from shallow Pliocene sandstone reservoirs began during the early 1950s. Currently, operators are targeting deeper sandstone reservoirs where conventional formation evaluation techniques are often inadequate. Clay volume, water saturation, and reservoir quality are highly variable and unpredictable based on only conventional logs. Complex mineralogy with high potassium feldspar and mica mineral content affects natural gamma ray measurements and influences density, neutron, and acoustic responses. A strategic forward plan was designed to help overcome these challenges and successfully address formation evaluation challenges as part of these new reservoir targets. Nuclear magnetic resonance (NMR) was added to the formation evaluation program to help address such challenges. This technology was integrated with conventional formation evaluation measurements primarily to reveal the total and effective porosity distribution and to estimate clay volume and permeability. Direct fluid typing was also applied to provide native oil viscosity and calibrated permeability. This paper discusses NMR-based methodology for direct clay volume estimation in a complex reservoir of the Pannonian Basin.