ASSESSMENT OF NATURAL GAS SOURCE ROCK POTENTIAL IN USISYA- MBAMBA BASIN IN LAKE MALAWI

An essential first stage in the exploration and exploitation of hydrocarbons is the assessment of natural gas source rock, which provides insight into the origins and methods of hydrocarbon discovery. The evaluation of Malawi's Usisya-Mbamba basin's source rock potential for natural gas is discussed in this article.
The geochemical investigation of the basin was carried out by the study using secondary geochemical data, including rock eval pyrolysis analysis, vitrinite reflectance, literature review, and TOC. Additionally, geochemical parameters like PI, TOC, S2, R0, and Tmax were used in the study.
Using scatter plots of TOC versus S2, Tmax versus PI, R0 versus depth, and table reference, respectively, the study determined the organic matter content, thermal maturity, and vitrinite reflectance of the source rock.
Ultimately, the data showed that the organic richness of the source rock in the basin ranged from fair to good, with the maximum TOC being 3.51 weight percent. Low vitrinite reflectance and immaturity characterize the source rock. This implies that natural gas production in the Usisya-Mbamba basin is possible, but more maturation of the organic matter is required. As the basin shrinks and the organic debris is buried deeper, this could eventually occur. On the other hand, igneous intrusions or strong geothermal gradients may quicken maturation. To validate this potential and determine whether producing gas from the basin is economically feasible, more research is necessary.

An essential first stage in the exploration and exploitation of hydrocarbons is the assessment of natural gas source rock, which provides insight into the origins and methods of hydrocarbon discovery. The geochemical investigation of the basin was carried out by the study using secondary geochemical data, including rock eval pyrolysis analysis, vitrinite reflectance, literature review, and TOC. Using scatter plots of TOC versus S2, Tmax versus PI, R0 versus depth, and table reference, respectively, the study determined the organic matter content, thermal maturity, and vitrinite reflectance of the source rock. Ultimately, the data showed that the organic richness of the source rock in the basin ranged from fair to good, with the maximum TOC being 3.51 weight percent.

Situated in the northern part of Lake Malawi, the Usisya-Mbamba basin is a sedimentary basin in a modern lakebed deposition context (Ellis et al., 2015). This basin, which is about 30 kilometers wide and 100 kilometers long, is distinguished by a significant buildup of sedimentary rock layers that include limestones, sandstones, and shales (Robertson, 2020). This basin was chosen because it is thought to be situated along the deepest part of the lake, which may provide the perfect conditions for retaining sediments and encouraging the production of source rocks.

Traditional authority: Lake Malawi

District: NkhataBay

Coordinates: -11.59605, 34.4874