Marginal field development: the nigerian experience


SOURCE ROCKS AND MATURITY



Download 3.35 Mb.
Page7/8
Date11.02.2018
Size3.35 Mb.
#41105
1   2   3   4   5   6   7   8

SOURCE ROCKS AND MATURITY
The source rock in the JDZ is considered to be the Akata shale. Additional source rock potential exists in lacustrine deposits of the pre-delta rift sequences. Thermal modeling indicates that sediments situated in the northern sector of the JDZ are within the maturity window.


RESERVOIRS
Reservoir rocks in the area are sourced from clastic input from the Niger Delta. These are essentially deep sea turbidites consisting of channel sands and basin floor fans. Porosities in these reservoir can be as high as 20% and permeabilities are generally good.


TRAPPING
Possible hydrocarbon accumulations in the JDZ are essentially structural in nature. However, there is significant potential for stratigraphic traps, especially in the zone of minor structuration. Two distinct domains have been identified in the toe thrust zone. These are:

i) The simple thrust domain


ii) The imbricate domain made up of

a. A proximal imbricate sub-domain


b. A distal imbricate sub-domain







The structures within the thrust domain are compressional in origin and consist of simple thrust sheets. The average width of the individual thrust sheets is of the order of 5 km. This domain presents large structural closures which are likely to be less fractured due to exposure to lesser compressional forces.
The proximal imbricate sub-domain is situated to the southeast of the simple thrust domain. Structural dips in this area are high and the average width of the individual thrust sheets are of the order of 1 to 2 km. The distal imbricate zone is situated to the southwest of the of the simple thrust domain with individual thrust sheets of the order of 2 to 3 km.


PROSPECTIVITY
Approximately 30 leads and prospects, essentially structural in nature have currently been identified in the in the JDZ. Seismic sections show excellent reflection amplitudes with several prospects presenting stacked objectives. Flat spots indicative of fluid contacts have been identified on several of the prospects.






http://www.aapg.org/datashare/data_020/Figure16_poster_size.pdf



Download 3.35 Mb.

Share with your friends:
1   2   3   4   5   6   7   8




The database is protected by copyright ©ininet.org 2024
send message

    Main page