STRUCTURES AND HYDROCARBON PROSPECTS IN EMI FIELD, OFFSHORE NIGER DELTA

Abstract

The Niger Delta is ranked among the world’s major hprovinces in the world. Oil and gas in t he Niger Delta are mainly trapped in sandstones and unconsolidated sands in t he Agbada formation and the structural traps are no t easy to map precisely because they are very slight, not obvious and very complicated. The main aim was to determine the stru ctures and hydrocarbon prospects in Emi-field, off shore Niger Delta using seismic data integrated with well logs. Four (4) h orizons namely L1, L2, L3 and L4 were selected and structural maps drawn for each of the horizons. Fault closures of high quality hydro carbon prospects were identified and delineated. The integration of seism ic data with well logs greatly improved the extent of accuracy and exactness of structural maps in hydrocarbon prospects and its de velopment in Emi Field. --------------------------------------------------- --------------------***---------------------------- The Niger Delta is ranked among the world’s major hydrocarbon provinces in the world. It is the most important in the West African continental margin. Oil and gas in the Niger Delta are primarily produced from sandstones and unconsolidated sands mainly in the Agbada formation. The goal of oil and gas exploration is to identify and delineate structural traps suitable for profitably exploitabl e accumulations and delineate the extent of discoveri es in field appraisals and development. These traps are very sl ight, not obvious and very complicated and are therefore not easy to map precisely. Major improvements in seismic and well logs have made it possible to map such structural arrang ements with high degree of accuracy and exactness. Seismic profiles provide almost a continuous latera l view of the subsurface by defining its geometry and providi ng an estimate of the acoustic impedance which is related to the formation densities and velocities. However, vertical details are limited due to length y duration of the individual seismic wavelets and the occurren ce of overlapping wavelets from closely spaced reflectors . Well logs are limited in their definition of lateral variatio n of subsurface parameters. Thus, the extent of accuracy in mapping complicated structural plays would be improved greatly by combining seismic data with well logs ([1]; [2]; [3 ]). In addition, the risk associated with finding oil and gas in very slight, not obvious and complicated structural plac es will be reduced tremendously since such integration will he lp to discern differences between poor and rich reservoir s and also greatly improve the extent of accuracy and exactnes s of the structural maps in hydrocarbon prospects and its de velopment. In this research, 3-D seismic reflection data were integrated with well logs so as to characterize the subsurface geometry and also determine the structures and hydrocarbon p rospects of the field. 1.1 Location and Geological Setting of the Field