Seismic interpretation and petrophysical analysis for hydrocarbon resource evaluation of ‘Pennay’ field, Niger Delta

Abstract

Seismic interpretation and petrophysical assessment of borehole logs from seven wells were integrated with the aim of establishing the hydrocarbon reserves prior to field development which will involve huge monetary obligation. Four hydrocarbonbearing sands, namely Pennay 1, 2, 3 and 4 were delineated from borehole log data. Four horizons corresponding to near top of mapped hydrocarbon-bearing sands were used to produce time maps and then depth structural maps using checkshot data. Three major structure-building faults (F2, F3 and F5 which are normal, listric concave in nature) and two antithetic (F1 and F4) were identified. Structural closures identified as rollover anticlines and displayed on the time/depth structure maps suggest probable hydrocarbon accumulation at the upthrown side of the fault F4. Petrophysical analysis of the mapped reservoirs showed that the reservoirs are of good quality and are characterized with hydrocarbon saturation ranging from 56 to 72%, volume of shale between 7 and 20% and porosity between 25 and 31%. Pennay 2 and 3 have a better relative petrophysical ranking compared to other mapped reservoirs in the study area. Dissimilarity in the petrophysical parameters and the uncertainty in the reservoir properties of the four reservoirs were considered in calculating range of values of gross rock volume (GRV) and oil in place volume. This research study revealed that the discovered hydrocarbon reserve resource accumulations in the Pennay field for the four-mapped reservoir sand bodies have a total proven (1P) reserve resource estimate of 53.005MMBO at P90, 59.013MMBO at 2P/P50 and 65.898MMBO at 3P/P10. Reservoir C, the only interval with a gas cap, has a volume of 7737MMscf of free gas at 1P, 8893.2MMscf at 2P and 10185.2MMscf at 3P. These oil and gas volumetric values yield at 1P/ P90 total of 137.30MMBOE, 154.9MMBOE at 2P and 171.515MMBOE at 3P. Reservoirs B and D have the highest recoverable oil at 1P, 2P, and 3P values of 5.265MMBO and 10.70MMBO, 12.053MMBO and 5.783MMBO, 13.557MMBO and 6.244MMBO, respectively.

Reservoir Evaluation and Volumetric Analysis of Rancho Field, Niger Delta, Using Well Log and 3D Seismic Data

“…Shale volume (Vsh) was estimated, using the [7] formula in Equation ( 1), which uses values from the gamma ray (GR) [8] in Equation ( 2).…”

Seismic Data Interpretation and Petrophysical Analysis of Kabirwala Area Tola (01) Well, Central Indus Basin, Pakistan

“…As shown in Figure 1b, Sargodha high is at the north of the CIB, Indian Shield is at the east, an axial belt is at the west, and finally Sukker Rift is located at the south [10]. The Punjab platform was the least affected during Himalayan orogeny; therefore, it possesses non-tectonic origin structures [11]. It also has no exposure to bedrocks.…”

Reservoir characterization and identification of new prospect in Srikail gas field using wireline and seismic data

“…To minimize drilling risk and maximize well and reservoir productivity, adequate analyses of seismic and petrophysical data are very important (Ameloko et al 2019). Many researchers conclude that integration of seismic and well log data plays an important role in determining the structural framework and reserves of a field (Fajana et al 2019;Owolabi et al 2019;Oyeyemi et al 2018Oyeyemi et al , 2019Sanuade et al 2018). In fact, the combination of structural interpretation, seismic stratigraphy, core data and logging, geological knowledge of depositional facies and modeling are crucial elements in building reservoir geological model and characterization (Norden and Frykman 2013;Edigbue et al 2015;Jegede et al 2015;Akm et al 2016;Al-Fatlawi 2018;Eahsanul Haque et al 2018;Kalu et al 2019).…”