Sequence Stratigraphic Interpretation of FX-1 and FX-2 wells, Onshore Western Niger Delta, Nigeria

Abstract

The area of study is a portion of the Greater Ughelli Depobelt in Niger Delta Basin. The main aim of the paper is to interpret the sequence  stratigraphy of FX-1 and FX-2 wells by employing data sets from biostratigraphic data and well logs. Standard laboratory techniques were used for  data treatment while computer software such as Petrel and StrataBugs were used for data simulation, processing, integration and interpretation. Sedimentology, interpreted gamma ray and resistivity well logs integrated with biostratigraphic data were utilized to define the candidate maximum flooding surfaces and sequence boundaries. The wells have the following distributions of sequences: FX-1 well have five depositional sequences with eight candidate maximum flooding surfaces at depths 10011 ft., 9509 ft., 9437 ft., 6362 ft., 5752 ft., 5507 ft., 5161 ft. and 4816 ft. dated 34.0 Ma, 33.0 Ma, 31.3 Ma, 28.1 Ma, 26.2 Ma, 24.3 Ma, 23.2 Ma and 22.0 Ma and seven candidate sequence boundaries at 9616 ft., 6656 ft., 6116 ft., 5639 ft., 5424 ft., 4859 ft. and 4581 ft. dated 33.3 Ma, 29.3 Ma, 27.3 Ma, 24.9 Ma, 23.7 Ma, 22.2 Ma and 21.8 Ma, respectively. FX-2 well have four depositional sequences, five candidate MFSs were identified at 7764 ft., 7196 ft., 6721 ft., 5862 ft. and 5571 ft. dated 34.0 Ma, 33.0 Ma, 31.3 Ma, 28.1 Ma and 24.3  Ma and five candidate SBs at 6941 ft., 6029 ft., 5688 ft., 5653 ft. and 5542 ft. dated 32.4 Ma, 29.3 Ma, 27.3 Ma, 24.9 Ma and 23.7 Ma respectively. The correlation of the two wells and sequence stratigraphic interpretation is a supplementary understanding of the subsurface geology of the Onshore, western Niger Delta area of Nigeria.

Keywords: Bio-stratigraphic data, Well logs, Sequence stratigraphy, Well correlation.