OICC Press Iranian Journal of Earth Sciences 2228-785X 17 1 2025 01 10 Reservoir characterization and hydrocarbon volume estimation of “Lamba” reservoir in Central Swamp depobelt, Niger Delta, Nigeria 1 11 10.57647/j.ijes.2025.1701.02 EN Ngwaka Chibuzor Alexis Department of Geology, University of Nigeria, Nsukka, Enugu State Nigeria https://orcid.org/0009-0000-9602-7467 Anyiam Okwudiri Aloysius Department of Geology, University of Nigeria, Nsukka, Enugu State Nigeria https://orcid.org/0000-0001-5133-5087 Okeugo Gabriel Chukwudike Department of Geology, University of Nigeria, Nsukka, Enugu State Nigeria https://orcid.org/0000-0002-2611-110X Okeugo Gabriel Chukwudike Department of Geology, University of Nigeria, Nsukka, Enugu State Nigeria https://orcid.org/0000-0002-2611-110X Ibemesi Onyedikachi Peter Department of Geology, University of Nigeria, Nsukka, Enugu State Nigeria https://orcid.org/0009-0009-2790-6973 Journal Article 2025 01 10 The reservoir quality assessment and the associated risks of the “Lamba” reservoir in the Central Swamp depobelt of the Niger Delta were carried out. These were achieved using integrated exploration techniques of well log sequence stratigraphic correlation, 3-D Seismic interpretation, formation evaluation, play risk assessment (PRA), volumetrics, and risk volume assessment (RVA). Sequence stratigraphic correlation along strike direction indicates a lateral continuity of the reservoir and vertical facies changes down dip. Structural interpretation reveals the presence of back-to-back structures, growth faults, synthetic and antithetic configurations, the major hydrocarbon migration pathway, and the trapping mechanism. Formation evaluation showed that the “Lamba” reservoir possess a net-to-gross value of 0.857; evidence of good sand development, average effective porosity (Øe) value of 0.134 v/v, and hydrocarbon saturation of 0.977 v/v. Analysis of play risk assessment reveals that the delineated prospect (Zircon) is located in the low-risk part of the study area. Volumetric estimation showed that hydrocarbon initial in place (HCIIP) was 6.6 Bscf of gas. Risk volume assessment showed that the reservoir has a probability of success (POS) of 0.228 and a risk volume of 1.5Bscf which suggests a decent hydrocarbon potential for the field.