http://hdl.handle.net/123456789/10352 2026-11-08T20:36:09Z 2026-11-08T20:36:09Z Ammad Ali Tariq http://hdl.handle.net/123456789/19033 2025-02-07T10:54:48Z 2907-01-01T00:00:00Z

2-D Seismic Data Interpretation of Qadirpur Area, Pakistan Ammad Ali Tariq Aim of the study is to interpret 2D-Seismic Reflection time section of the Qadirpur Area (Sindh Province) Pakistan. This seismic section is a Pre-stacked time migrated section and was provided by the Department of Earth Sciences, Bahria University Islamabad and this line bears the title 985-QPR-03 It is about 40 Kms in length and is oriented in SW-NE direction. OGDC acquired data in October 1998 and processed it in January 1999. The velocity information is in the form of RMS. DIX interval and DIX average at different times is given, and is provided at selected S.P. RMS velocity varies from 1500 m/s to 5000 m/s Interpreted part of this line from S.P. # 460 to S.P # 720, with CDPs from 920 to 1440 Length of this part of seismic section is 13 Kms. For interpretation of this part of Seismic section, four reflectors and 2 faults are marked on the basis of prominent reflections from subsurface horizons due to changes in lithology and diffractions. Using the RMS velocity given in the velocity panels on seismic section for selected shot points, calculate the time on constant velocity interval of 100m/sec Then using these calculated time and velocity values prepare the Iso-velocity graph and Iso-time graph (for mean line method) by taking constant velocity and time respectively, In Mean line Method of velocity estimation, a velocity vs time graph is prepared. From this graph, a mean average velocity is determined. From Seismic Section, arrival times (two ways) of each marked reflector are determined, Using these arrival times, Time Section is prepared. Also using these arrival times, calculate the average velocity for these times on mean line graph and then the depth of each reflector has been calculated using s(vt)/2 and is represented in Depth Section. Depth Section provides a reliable picture of reflectors and structures present in the subsurface of the area. Well correlation is also done, which satisfy the calculated depths, so horizons have been marked Interpretation of the Project Area shows that, extensional regime and calm environment prevails in the area. Reflectors are almost flat-lying, whereas Horst and Graben structures have been found. Supervised by Mr. Rashid Jamil

2907-01-01T00:00:00Z Mohsin Abbas, 09-262242-028 http://hdl.handle.net/123456789/21804 2026-10-07T10:42:03Z 2026-01-01T00:00:00Z

Evaluation of Seismic Stations Performance and Background Noise Levels in Northern Pakistan Using Power Spectral Density Analysis Mohsin Abbas, 09-262242-028 Anything built from a seismic recording inherits the imperfections of that recording, whether it is a routine earthquake location or a probabilistic hazard assessment. This study assesses the recording performance of four broadband stations of the Pakistani seismic network, at Islamabad, Jhelum, Lahore and Peshawar, using a common set of eight regional earthquakes recorded during 2017 with magnitudes of 4.0 to 5.2 and epicentral distances of 115 to 1314 km. P-wave arrival times were picked by hand and compared with times predicted from a standard velocity model, which gives one residual per event-station pair. Those residuals were then summarised at each station across the eight events. The four stations do not perform alike. Islamabad has the smallest residuals, a mean of 13.79 s and a root-mean-square of 17.22 s, and it records the lowest value for five of the eight events. Peshawar has the largest, 27.53 s and 29.67 s, and the highest value for six of the eight. Its mean and median sit close together, so its residuals are uniformly large rather than distorted by a few outliers. Jhelum and Lahore fall between the two at 20.79 s and 21.04 s, close enough to be indistinguishable on a sample this size, though they arrive there by different routes: Lahore's figure rests on a single extreme value, while Jhelum's builds up evenly. Correlation with epicentral distance separates the stations more sharply than the residual sizes do. Islamabad shows no dependence (r = +0.13, p = 0.75). Lahore and Jhelum both give strong Pearson correlations, r = +0.81 and r = +0.77, but both weaken substantially under rank correlation, which means a handful of distant events is driving them. Peshawar's correlation is moderate (r = +0.68), and here the Pearson and Spearman values agree. The increase with distance at Peshawar is therefore real, and it sits on top of an offset that is already present at the shortest distance. Power spectral density analysis, referenced to the Peterson (1993) noise models, places all four stations between the low- and high-noise bounds, and nearer the high-noise bound at short and intermediate periods. Twenty-eight of the thirty-two records reach maximum power between 0.93 and 1.98 s. That the same band recurs across a tenfold range of epicentral distance points to shallow structure beneath each site rather than to the source or the propagation path. The clearest result comes from setting the two analyses side by side. Peshawar records the strongest and most reproducible spectra of the four stations and still carries the largest residuals; Islamabad shows the reverse. Signal strength therefore does not account for timing performance. That points towards station timing, metadata or picking practice rather than towards siting or instrumentation. The study closes with station-specific recommendations, and the same approach can be applied to further stations using records the network already produces. Supervised by Dr. Muhammad Fahad Mehmood

2026-01-01T00:00:00Z Sarmad Azhar, 01-262232-026 http://hdl.handle.net/123456789/21772 2026-10-06T13:16:07Z 2026-01-01T00:00:00Z

Quantitative Reservoir Characterization by Integrating Rock Physics Analysis and Seismic Inversion, Offshore Indus Basin of Pakistan Sarmad Azhar, 01-262232-026 The Offshore Indus Basin, along Pakistan's passive continental margin in the Arabian Sea, holds a thick Cenozoic clastic succession with all the essential petroleum system elements, yet remains lightly drilled and commercially unproven. Conventional seismic interpretation maps structure adequately but cannot uniquely resolve porosity, lithology, and fluid saturation at the resolution exploration decisions require. This study addresses that gap by applying an integrated quantitative reservoir characterization workflow — combining petrophysical evaluation, structural seismic interpretation, modelbased acoustic impedance inversion, and rock physics analysis to a Miocene–Pliocene clastic interval within the basin. The dataset comprises eleven 2D seismic lines and wireline logs from three wells, two of which carry the log suite required for petrophysical evaluation. The reported tops place all three wells on a common chronostratigraphic scheme but are too widely spaced to define reservoir units, so four reservoir intervals were established within that framework by gamma ray and deep resistivity correlation, two in the Late Miocene and two in the Middle Miocene, and all subsequent analysis was conducted within them. Petrophysical analysis in GVERSE yielded shale volume (Larionov non-linear correction), average and effective porosity, and water saturation. Seismic interpretation in Kingdom, calibrated by synthetic seismograms, produced fault and horizon picks and time and depth structure maps for four key horizons. Model-based post-stack inversion in Hampson-Russell was applied to two of the strike lines, SPC-86-9007 and SPC-86-9019, and rock physics crossplots of Vp/Vs against P-impedance, bulk density and S-impedance, colour-coded by computed gamma ray, supplied the litho-fluid discrimination template. The results define a vertically stacked sand–shale system in which reservoir quality is governed principally by clay content. All four intervals are shale-rich when averaged over their gross thickness, with shale volumes of 51 to 77 per cent, and the clay correction reduces average porosities of 21 to 32 per cent to effective porosities of 6 to 11 per cent. Water saturations are high throughout, at 80 to 98.5 per cent. The deeper PakCan-01 interval at 2700–2730 m is the cleanest and returns the highest effective porosity and hydrocarbon saturation, at 10.02 and 20.01 per cent; the two Sadaf-01 intervals return 10.64 per cent hydrocarbon saturation; and the shallower PakCan-01 interval at 1710–1770 m is effectively water-bearing at 1.50 per cent. Inversion, validated by well-tie correlations of approximately 0.99, imaged laterally coherent low-impedance anomalies confined to theviii reservoir interval on both inverted lines and spatially coincident with fault-bounded structural closures persistent across all four mapped horizons. Because the computed water saturations are high and the shale volumes substantial, those anomalies are attributed principally to variation in clay content and porosity rather than to fluid fill, and the crossplots separate the data by lithology more clearly than by fluid. The fluid interpretation therefore remains an inference from elastic response rather than a measurement; pre-stack simultaneous inversion, shear velocity control in more than one well, and 3D coverage are recommended as the next steps. Supervised by Dr Iqbal Hajana

2026-01-01T00:00:00Z Muhammad Rashid, 01-262232-017 http://hdl.handle.net/123456789/21947 2026-10-27T11:42:39Z 2026-01-01T00:00:00Z

Application of Post-Stack Seismic Inversion for the Characterization of Porous Reservoir Sand, Gambat Block, Central Indus Basin, Pakistan Muhammad Rashid, 01-262232-017 The Lower Goru C-sand of the Gambat Block, Central Indus Basin, is a proven gas reservoir whose quality varies sharply over short distances. Lateral facies change, diagenetic porosity heterogeneity and fault compartmentalization produce amplitude responses that conventional interpretation cannot resolve unambiguously, and only three wells penetrate the productive interval. This study characterizes the porous reservoir sand by combining four methods: petrophysical evaluation of Tajjal-1, Tajjal-2 and Tajjal-3 in GVERSE Petrophysics; structural and stratigraphic interpretation of a 3D seismic volume in IHS Kingdom; post-stack seismic inversion; and AVO analysis with supporting rock physics, both carried out in CGG Hampson-Russell. Petrophysical evaluation identifies the reservoir intervals as clean quartzose sandstone with low shale volume, developed effective porosity, elevated deep resistivity and reduced water saturation. Neutron-density crossover within the clean sands, corroborated by the density-neutron and M-N cross plots, indicates gas rather than brine. Seismic interpretation traces the Upper Goru marker, the Lower Goru marker and the C, B and A sand intervals across three inlines and three crosslines. The horizons are laterally persistent in both structural directions and gently deformed, cut by a single fault near Tajjal-3, and the gridded picks were converted to depth using velocities from the wells. Model-based inversion weas applied to the same volume. At Tajjal-1 the sparse-spike result reaches a correlation of 0.9888 with a residual error of 0.1968, and the model-based result 0.9986 with an error of 0.0829. Both resolve the porous sands as laterally coherent low-impedance zones at the same positions, and the horizon maps of the top C and top B intervals show corresponding fairway patterns, which indicates that the mapped distributions do not depend on the choice of algorithm. Gassmann fluid substitution and angle-gather modeling identify an AVO class 2 response, in which the reflection is weak at normal incidence and its magnitude increases with offset. The Vp-Vs, acoustic impedance against Poisson's ratio, and lambda-rho against mu-rho cross plots separate gas sands from brine sands and shales, and extended elastic impedance at a chi angle of 32° gives the clearest discrimination obtained in the study. The low-impedance fairways mapped on the top B interval are the most prospective targets in the block. Because the reservoir is weak at near offsets and develops its amplitude only at far offsets, its AVO signature can be overlooked where a class 3 response is assumed Supervised by Dr Fahad Mehmood

2026-01-01T00:00:00Z