Use of Sedimentological and Geochemical Parameters to Evaluate the Lithologies and Geochemical (Na/Zn and K/Mn) Ratios of OGE-1 Well, Niger Delta Basin

This work focuses on subjecting ninety (90) sidewall core well samples to sedimentological and geochemical parameters to determine the lithologies and the geochemical ratios of the OGE-1 Well in the Niger Delta Basin. The sedimentological analysis with sample description yielded lithologies that are sand, shaly sand, sandy shale and shale. The sand lithologies ranged from fine to coarse grained, well sorted to poor sorted at different depths, while the shale lithologies ranged from light to dark coloured shales which is controlled by the organic matter content in the shale. This finally produced a lithologic frame work of the well. The result of the geochemical analysis led to the creation of the geochemical ratio of Na/Zn (0.739 \u2013 5.610) and K/Mn (21.170 \u2013 69.37) for 90 side wall core samples. Na and K had variations in their graphs showing intermittent alternating abundance downhole. Na and K being components of the weathering of feldspars are indicative of abundance of clay minerals. The variation of the Na/Zn and K/Mn profile indicates the alternate deposition of clay and sand size deposits giving the environment of deposition to be paralic

Comparative Assessment of the Geotechnical Properties of Residual Soils in Parts of Awka and Abuja Areas of Nigeria

Residual soil samples from the zone of accumulation were collected from road-cut exposures in Awka (Aks), and Abuja (Abs) within the Nigerian sedimentary and Basement terrains respectively. The soil samples were tested for their geotechnical properties with a view to ascertaining their index and engineering properties in order to determine their suitability for use as construction materials. The liquidity and consistency indices are -0.09 &-0.49, and 1.09 & 1.49 for Abs and Aks respectively. B Aks and Abs have shear strength (84.84 & 88.91) KN/m2, frictional angle; (44 & 33)0 , cohesion; (0.1 & 31.65) KN/m2, unconfined compressive strength; (85.89 & 97.49) KN/m2, B maximum dry density; (18.54 &15.35)KN/m3 with optimum moisture content of (14.2 & 22.5)% and group indices of (0.022 & 9.54) respectively. Overall, with adequate drainages, Abs will make a better subgrade in flexible pavement design whereas Aks will be better suited for use in slopes and embankments.http://dx.doi.org/10.4314/njt.v33i4.2

A study on the interpretation of spontaneous potential and resistivity logs in layered aquifer sequence of Pondicherry Region, South India

Geophysical logs provide a strong mechanism for interpretation and determination of the depositional environments, facies and also help in interpretations of hydrogeologic units. Spontaneous potential (SP) and resistivity logs can be used as an indicator of textural parameters. Pondicherry region has a complicated geology and with formation of different ages. The boreholes (BH) of this region are examined for litholog, SP and resistivity from four different BH locations, viz, Ariyankuppam, Chinnaverampattinam, Thavalakuppam and Nallavadu. These locations were studied and interpreted by using the shapes of the curves to identify the depositional environments, and this was later compared with the vertical litholog profile. Comparing the variation of these logs, the lateral variation of sedimentary facies was also attempted. The average resistivity values of Ariyankuppam, Chinnaverampattinam, Thavalakuppam and Nallavadu are 42.4, 30.4, 50.4 and 28.3 Ωm, respectively. Majority of the resistivity values corresponds from fine- to medium-grained sand, clayey pebbles, fine to very coarse sand and clayey sand with lignite. Frequency of resistivity values in each BH were identified for determining the dominant representative grain size. The study has pointed out the lithological variation of the system laterally and vertically using geophysical well logs