Depositional Cycles Within The Upper Kharaib Formation Of An Abu Dhabi Oilfield
S.N. Ehrenberg, S.W. Lokier, L. Yaxin and R. Chen
Event name: First EAGE Workshop on Evaluation and Drilling of Carbonate Reservoirs
Session: Diagenetic Controls on Carbonate Reservoirs
Publication date: 04 October 2017
Info: Extended abstract, PDF ( 820.34Kb )
Price: € 20
The fact that reservoir sub-zones (previously suggested to be fourth-order parasequence sets) are defined by dips in the porosity log profiles, reflecting increased stylolite frequency, indicates that these boundaries are diagenetic in character. Nevertheless, the correlation of these features over tens to hundreds of kilometers indicates an underlying depositional control. We suggest that the link between sea level and diagenesis is depositional clay content, which facilitates stylolitic dissolution. Profiles of bulk-rock alumina analyses in the studied cores tend to confirm higher clay contents at the sub-zone tops. Possible factors promoting clay influx onto a carbonate shelf during falls in sea level include increased stream gradients and a more humid climate, causing greater rainfall and higher weathering rate.