No abstract

This study was carried out by using well logs to evaluate the depositional environments and hydrocarbon reservoirs in the Otuma oil field, Niger Delta basin. The gamma motif/model within- study interval in the drilled well shows blocky, symmetrical, and serrated shapes which suggest a deltaic front with mouth bar to a regressive - transgressive shoreface delta respectively. A correlation was done on the well logs across the wells and the ten well logs were used to evaluate the petrophysical characteristics of the reservoirs. The reservoirs showed highly porous and permeable channels where the wells were used for the characterization. The ten reservoirs were mapped at a depth range of 2395 m to 2919 m with thicknesses varying from 4m to 135m. The petrophysical results of the field showed that the porosity of the reservoirs ranges between 0.10 to 0.30, and permeability from 48 md to 290 md; the water saturation ranges from 0.39 to 0.52, and hydrocarbon saturation from the field 0.48 to 0.61. The By-passed hydrocarbons identified in low resistivity pay sands D4 and D3 at depth 2649 m to 2919 m, respectively were also evaluated and will be put to production in the field.

The Southern Bida basin consists of the Lokoja, Patti, and Agbaja formations. This study focuses on the Lokoja formation and samples gotten were used for petrography and heavy mineral analysis. Results of all analytical techniques employed in the study are presented here. A critical assessment of each set of results and their integration aided the proper interpretation and useful discussion. This study focuses on the Southern Bida Basin, specifically the Lokoja Formation because the exposures of Patti are poorly exposed. Outcrop samples were obtained from the exposed sections of the study area in Kabawa and Robinson street respectively. Different features were observed, such as the thickness of the exposure, the nature of the lithology, color, and sedimentary structures. The dominant lithologies in the area include sandstone and ironstone. The sandy facies are generally arkosic characterized by poorly sorted very fine to conglomeratic sandstone sequence. Laboratory investigations of samples included petrography and heavy mineral analysis. Sandstone samples were collected from the study area. Each sample was divided into two parts: the first part for petrographic studies and the second part for heavy mineral analysis.

The research area Jos Plateau is located in Nigeria's north-central region. Because of the presence of hills and mountains, it is a typical Basement Complex topography, making access to potable water difficult. Data Collection was carried out in two stages namely: Desk Study and Field Geophysical Surveys. The desk study involved a review of published work on the area as well as sourcing of maps. An effort was put in place for a geotechnical procedure using both geophysical and geological approaches. With the help of previous works of literature about the area, background information was obtained. This was followed by a reconnaissance survey. The topographical map (NARAGUTA SHEET 168NE) was obtained. The drainage pattern was observed and traced. The boundary of the research work was delineated between latitudes 90 30ʹ 00ʺ N to 100 00ʹ00ʺ N and longitudes 80 30 ʹ 00 ʺ E to 90 00 ʹ E. The map was partitioned into grids for the purpose of locating VES locations (Vertical Electrical Sounding). To obtain the underlying information needed for this research, resistivity sounding was used to collect data throughout such river channels. The sounding and data were collected using the Nile Drill tech terameter. A lineament map was created using satellite images, and a hydro geophysical survey was conducted along these drainage patterns. The structural expressions were compared to the characteristics revealed by the geophysical survey. Due to the changes that occur between beds of dry, water-bearing, sediment, different lithology, and weathering rocks, vertical profiles and their characteristics were determined. The data were analyzed, processed, plotted, and interpreted. Various cross-sections were drowned and correlated. Despite the fact that the sounding was carried along river channels, it revealed generally that the whole study area can be said to be of low groundwater potential.

The “Assessment of the southwestern of the Cauto Basin and its oil and Gas possibilities in Cuba” was carried out with the objective of evaluating the southwestern part of the Cauto Basin in Cuba from the geological and geophysical point of view, with the southwestern of the Basin as a foundation of the petroleum system models. The method of investigation employed included interpretation of the seismic lines, the surface geology, the well logging data, gravimetric and magnetometrics data. The research was developed in three fundamental stages: I) Preliminary stage, II) Data processing and III) Interpretation of results/conclusions and recommendations. The characterization of sedimentary structures was assessed, and the evolution of the studied basin was also realized. Based on the result of this study, the origin of Cauto Basin can be linked to the geological event that occurred in the area towards the end of the Cretaceous era which involves complex sedimentary processes with associated collusions and extension of tectonic transcurrente. This leads to formation of Delta zones and important fans, which were the product of rapid sedimentation and slow subsidence. Furthermore, the result reveals that the studied interval can be described as a potential reservoir for being part of the fan and deltaic zone. There is evidence of the presence of hydrocarbon within the studied interval, but probing further depth has the potential of more discovery within the source rock since only the Tertiary reservoirs were evaluated.