Injectivity Impairment Due To Geochemical Reaction And Its Effect On Laboratory Interpretation
N.Z. Mat Razali, K.A. Mustapha, S. Gödeke, M.A. Abu Bakar, S.S. Md Shah, Z.A. Abu Bakar and S. Misnan
Event name: EAGE Conference on Reservoir Geoscience 2018
Session: Session 12: Unconventional Reservoirs
Publication date: 03 December 2018
Info: Extended abstract, PDF ( 584.75Kb )
Price: € 20
Overestimation and underestimation of injectivity impairment due to salt precipitation and mineral dissolution would risk the mathematical modelling for estimating the potential CO2 sequestration in Malaysian Limestone. In-depth knowledge to minimize the misinterpretation of laboratory data is critical to reduce the uncertainties during CO2 pilot injection. Therefore, a set of coreflooding experiment under reservoir conditions using representative native cores, supercritical CO2 and synthetic formation brine was conducted to understand the effect of induced salt precipitation towards injectivity result. Stabilization time in differential pressure (∆P), analysis of effluent collected after CO2 Water Alternating Gas (WAG) injection and pH reading are key indicators of laboratory data reliability for simulation. The experimental result demonstrated the existence of scale formation and halite precipitation after the samples were subjected to supercritical CO2 WAG for a duration of two weeks. In conclusion, proper experimental procedure and coreflood design during CO2 flooding are the main factors that would affect the reliability of injectivity data and the injection study must be conducted continuously as chemical reaction between CO2 and the fluid-rock system would impact the physical changes of the core samples.