Analysis of Pressure Versus Flow Regime of CO2 To Assess Matrix and Fracture Injection at In Salah, Algeria
B. Bohloli, E. Aker, F. Cuisiat, V. Oye and D. Kühn
Event name: Third EAGE CO2 Geological Storage Workshop
Session: Poster Session 2
Publication date: 27 March 2012
Info: Extended abstract, PDF ( 357.13Kb )
Price: € 20
This paper presents an analysis of CO2 injection history for three wells drilled into the water leg of the Krechba reservoir, In Salah, Algeria. The hydro-mechanical behaviour of CO2 storage is reflected in the injection history of wells. Detailed analysis of pressure versus flow rate was carried out to differentiate between periods of matrix and fracture injection and assess optimum injection pressure. The history clearly shows periods of CO2 injection into the reservoir (and possibly surrounding rocks) under fracturing conditions, thus providing the formation fracturing pressure and maximum matrix flow rate. The maximum applied pressure in all three wells has likely exceeded the fracturing pressure of the reservoir at various periods since project start-up. The findings are supported by other sets of data such as in-situ stress profile, empirically calculated fracturing pressure, FIT, LOT and microseismic events.