Geothermal Energy Prospects in Khairpur District: Subsurface Analysis for Community-Level Electricity Generation

Geothermal energy provides reliability with a constant flow of energy despite weather and geopolitical conditions. In Pakistan, the source of geothermal energy has been buried for years and waiting to be unearthed, and the condition of power supply and demand in Pakistan has been very crucial for decades. Thus, the significance of a nonrenewable energy source for power supply in Pakistan is an utmost requirement of time. The problem with unearthing geothermal energy in Pakistan is that it requires enormous funds and infrastructure. Henceforth, in this paper, a technical feasibility study is conducted on a geothermal source concealed in the subsurface of Khairpur Mirs District located in the province of Sindh, Pakistan. In fact, the selected location is a gas field where the produced fluid (gas and water) possesses an average temperature of 130 °C. The investigation in this study is conducted by collecting rock and fluid samples from selected gas fields and subjected to laboratory analysis. For rock samples, X-ray diffraction and scanning electron microscopy tests are conducted to evaluate the feasibility of fluid and thermal flow. Further, water samples are tested for PVT (pressure-volume-temperature) properties and thermal conductivity. Moreover, the electricity supply from evaluated tests is predicted, which will be provided to the local community settled near the gas field. The results of this study reflected that the crystallographic phase is present in each sandstone rock sample, which makes it highly feasible for fluid and thermal flow. The PVT test revealed that water samples reached the isothermal compressibility of 379.072 1/psi × 10⁶ with a density of 0.8503 g/cm³ at 130 °C. The thermal conductivity of oilfield water reached from 2.3 to 2.6 W/(m K) within 12 days, which is a positive sign of thermal conductivity escalation. Eventually, it is projected that 116,691.66 kWh/day of electricity can be produced by installing a small-scale geothermal power producing plant at the wellsite benefiting more than 46,676 people settled in the nearby vicinity of the geothermal well. Concludingly, this study supports the production of wellsite geothermal energy generation for community-level consumers settled in mobile locations of Khairpur Mirs District. The concept of using existing infrastructure of gas fields not only saves economic and logistic challenges but also resolves the surface handling problem of high-temperature fluid production at the wellhead.