STRUCTURAL PATTERNS AND LITHO-STRATIGARPHY OF ‘DIOK’ FIELD, EAST NIGER DELTA, NIGERIA AND ITS IMPLICATION FOR HYDROCARBON GENERATION

Abstract

Integration of 3D seismic data with well log information has been employed in determining the stratigraphy and structures within ‘Diok’ field, a Niger Delta hydrocarbon-bearing field. Four distinct seismic facies are recognized in the study area. They are seismic facies 1, which consists of transparent facies that are characterized by lack of acoustic impedance contrasts, it is interpreted to be the continental lithofacies of the Benin Formation. Seismic facies 2, which comprises discontinuous and occasionally inclined internal reflectors, they are found between 0.6 and 1.3s on the seismic sections of the study field, it mimics the transition between the continental and paralic lithofacies. High frequently occurring and continuous parallel reflections characterise seismic facies 3, which is between 1.3 and 3.0s on the seismic sections. They are interpreted to be the well-defined paralic lithofacies of the Agbada Formation. Seismic facies 4 are chaotic reflections found below 3.2s on the seismic sections and they represent thick shales of the Akata Formation. Structurally the field is interpreted to be a faulted anticline within a structural complex that involves series of basinward dipping normal faults. Two main fault blocks (A & B) that are further compartmentalized to smaller blocks at deeper levels and separated by series of small synthetic faults are observed in the field. Consistent and reliable fault interpretation was achieved in the study area through the use of seismic attributes and the pattern of faulting in the field indicates high degree of inter-block communications.