Identification of Gas Sand Horizons of the Rashidpur Structure, Surma Basin, Bangladesh, Using 2D Seismic Interpretation

Abstract

A total of 13 seismic sections were used for 2D seismic interpretation in order to assess the subsurface geometry of gas sand horizons and hydrocarbon prospect of the Rashidpur structure, Surma Basin, Bangladesh. Out of five reflectors, two selected reflectors were mapped for the study. The top of the Upper Gas Sand (R3) reflector was elongated in N-S with the axis swinging slightly to the east on the northern plunge. North-South trending thrust fault was identified in the eastern part which is parallel to the axial line of the structure. The reflection patterns of the gas sand horizons were parallel to each other and similar in nature. The reflection coefficients were positive at the base and negative at the top of the each gas sand horizons. Velocity dropped from 2562 m/s to 2177 m/s in the Upper Gas Sand (R3) and 4320 m/s to 3413 m/s in the Lower Gas Sand (R5) reflector. Bright spot and amplitude anomalies were identified on the top of the both gas sand horizons. The result depicts that the shape of the gas sand horizons is asymmetric anticline. The structure is compressed and elongated NNW-SSE trending anticline. The study reveals hydrocarbon potentiality of the structure.

Geometry of the Décollement Below Eastern Bangladesh and Implications for Seismic Hazard

“…The labels denote the source of each data set, where labels that begin with "W" or "S" indicate velocity data derived from well or seismic reflection data, respectively. Data sources are: Islam and Habib (2015) (W2), Najman et al (2016) (equation fitting sonic log data, E1, more information in supporting information Appendix 1.3), Sikder and Alam (2003) (L11), Zahid and Uddin (2005) (W3, W4, and W5), and this study (W1, W6, W7, L12, L15, L19, and L20). The "a" and "s" adjacent to L19 and L20 denote velocities sampled from anticlines and synclines within each profile, respectively.…”

“…Data sources are: Abdullah et al. (2015) (L24), Islam and Habib (2015) (L7, W2), Imam and Hussain (2002) (L6), Kabir and Hossain (2009) (L8), Lohmann (1995) (L5, L9), Maurin and Rangin (2009) (L25, L27), Murphy (1988) (L2, L4), Najman et al. (2012) (L1, L16, L17, L18, L22, L26, and L28), Najman et al.…”

Suitability Analysis of the Potential Gas Fields of Bangladesh for Carbon Dioxide Sequestration and A Simulation Approach for Titas Gas Field

“…So shallow distance short flow system exists here. The Rashidpur gas field has a depth of 1380-2787 m. The volumes of shale values were low within the hydrocarbon-bearing zones of Rashidpur gas field [15] and also the major fault is of narrower width but there are numerous other small faults running N-S trend on the eastern flank of the structure [16]. So the field is classified as "extensively faulted and fractured".It contains significant water bearing zones show in the table 1 for well-4 analysis.…”