Structural and 3D seismic attribute analysis for reservoir characterization in pearl field, offshore Niger delta

Structural and 3D seismic attribute analyses were conducted in the Pearl field, offshore Niger Delta basin in order to enhance hydrocarbon discovery and optimize development plans. The exploration and development success in this basin hinges on the accurate identification and characterization of potential reservoirs. To achieve the goals, well log analysis, petrophysical evaluation, fault interpretation, horizon mapping, volumetric estimation and seismic attribute analysis were all employed to delineate potential hydrocarbon prospects. Five reservoirs (A–E) were identified across the wells. The reservoirs are continuous and are hydrocarbon bearing sands. The petrophysical analysis revealed average porosity (24–28%), net to gross (75–98%), net thickness (77–213 ft), water saturation (29–42%), and hydrocarbon saturation (58–71%), indicating presence of good quality sands with very good to excellent porosity and high hydrocarbon accumulations. A total of eleven normal faults were picked across the seismic sections, one regional growth fault as well as multiple synthetic and antithetic faults. These faults aided migration of hydrocarbon and traps the hydrocarbon accumulations. The top of reservoirs (B and C) which are the major reservoirs were mapped. Two fluids were identified from reservoir B. The gas has an original volume (OGIP) of 90 million cubic feet while the oil has an original volume (OOIP) of 5.48 million barrel while in reservoir C, the fluid was identified to be oil with an original volume (OOIP) of 33.16 million barrels indicating that both reservoirs are commercially viable. In addition, the seismic attributes such as Root mean square amplitude, average energy, maximum magnitude, sweetness, and envelope attribute extracted from top of reservoirs (B and C) confirmed hydrocarbon-rich zones, enabling detailed mapping of reservoir boundaries. Hence, the study has improved the understanding of reservoirs identified in Pearl Field, Niger Delta, for development plans and this could be applied in similar geological setting for future hydrocarbon exploration.