Seismic Characterization to Identify Geological Structures and Petroleum Play in Lower Indus Basin, Pakistan

The Cretaceous shale intervals of Talhar and Sembar Formations – distributed in the Lower Indus Basin of Pakistan – are organic-rich shales that can act as shale gas plays. Two-dimensional seismic using synthetic modeling has been carried out in Khewari oil field to identify petroleum plays. This work was completed with the help of eight seismic processed and migrated lines. Based on structural interpretation different geological structures were marked. The seismic character, continuity, and coherency in seismic reflection patterns indicate that the area is under an extensional regime with normal faults pattern associated with horst and graben structure. This structure is favorable for the accumulation of hydrocarbon. The shales of Talhar and Sembar formations are overlying Chilton limestone, which is a proven reservoir. The isopach maps show that Talhar Shales and Sembar Formation are dipping towards the northeast. Precisely to characterize the reflector, a synthetic seismogram was employed to tie well tops and seismic profiles

Integrated Study of Geotechnical and Geophysical Methods to Assess the Soil Corrosion Potential for Construction Site

Corrosion of subsurface steel structures is very critical issue especially in moisture subsoil. The use ofphysiochemical properties such as pH, salts concentration, electrical resistivity is very common to quantify corrosivenature of subsoil. However, the laboratory measurements of these parameters are quite difficult due to time and budgetconstraints. In this work soil corrosion potential of a power plant site was evaluated using geophysical and geotechnicalinvestigations. Soil samples were collected from 15 boreholes drilled up-to 50 m depth for laboratory testing whereas 3probes of four electrodes vertical electrical sounding (VES) using Wenner configuration were also performed tomeasure the electrical resistivity of the subsurface soil up to 50 m depth. According to the USCS soil system silty clay(CL-ML) was interpreted as dominant material in all boreholes as shallow depth. Poorly graded sand (SP) including silt(SM) was found of variable depth in almost each borehole. The true resistivity values at the depth of 30 meters liesbetween the 19.9 ohm- meters to 59.8 ohm meters. All observation points of electrical resistivity survey VES-I, VES-IIand VES-III near-surface material show moderate soil corrosion potential which is favorable for design of earthing. Upto depth of 4 m, the values of resistivity 52.6 to 59.8 ohm-meters shows adequate estimation of corrosion. According tothe International standard these curves belong to bell type or K type curve of resistivity model. Their resistivity valueswith respect to depth show low to moderate corrosion potential which is satisfactory for construction at this depth afterapplying the nominal cathodic protections. Thus, electric pipe lines may be installed at this depth

Delineation of Ground Water Recharge Potential Zones in Lahore District, Punjab, Using Remote Sensing and GIS Techniques

Lahore is the provincial capital of Punjab and the second most populous city in Pakistan. Aquifer recharge rates have been continuously decreasing over a long period of time, which has caused a significant decline in the water table level. Rapid population growth, urban development, and industrialization have all raised the demand for water supplies. Due to significant infrastructural development, a considerable portion of the land is now impervious and rainfall now drains as surface runoff rather than recharging the aquifer level. Average annual rainfall, one of the primary sources used to replenish the Lahore aquifer, is insufficient to prevent the depletion of the water table, and River Ravi stays almost dry except in rainy seasons. Geographic information system (GIS) and remote sensing (RS) techniques are used to find suitable areas for replenishment in the Lahore aquifer system in order to enhance sustainability and prevent decreasing groundwater levels. Distance from the water channel, land use/land cover (LULC), slope, geology, drainage density, rainfall, lineament density, and soil type are the eight layers that have been integrated with the GIS overlay analysis. Thematic maps are generated using both conventional and remote sensing data. These maps are eventually converted to raster data. Very good, good, moderate, poor, and very poor are the five zones that have been delineated. A good to very good suitable part was found to constitute 46.34% of the total study area