Spectral decomposition-based temperature and water saturation-constrained dynamical simulations detect high-temperature geothermal energy resource

Quantitative-based reflection seismic reservoir simulations have revolutionized the imaging and characterization of sub-surface renewable energy resources, e.g., geothermal reservoir systems (GS). These GS have proven reserves of hydro-geothermal reservoir fluids zones (HRZ) within the depleted oil and gas field. These HRZs can develop cost-economic steam-to-electricity conversion systems. These HRZs can be converted into electricity after generating steam from high-temperature GS. However, imaging and characterization of HRZ within these GS are highly constrained by the fluctuations of anisotropic parameters, e.g., temperature, fluids phases of water-saturation, fracture intensity, salinity, fractured permeable zones, velocity, and density. These anisotropic parameters have a vital impact on seismic acoustic impedance (product of density and velocity). Hence, they create ambiguous seismic acoustic impedance signatures, which have a vital role during the imaging of GS. HRZ of GS is developed within the depleted oil and gas field. These GS are entirely constrained to the sub-surface geological settings. These sub-surface geological settings are developed within the typical depositional systems, which host the HRZ of GS. The accurate imaging and characterization of these GS is highly dependent on the optimizations of advanced imaging tools and their desired parameterizations. The seismic reflection and refraction data are the most advanced tools for imaging the sub-surface GS resources. However, the seismic reflection has a better resolution than the seismic refraction surveys. Therefore, there are certain frequency contents, which are responsible for accurately imaging these GS. Even the bandlimited seismic reflection data is also dependent on the selection of tuning frequency. So, this tuning frequency content is the key element in the accurate imaging and characterization of GS. This tuning frequency content is achievable using the continuous wavelet transforms (CWT) technology of spectral decompositions. CWT provides a better frequency resolution at lower frequencies and higher time resolution at higher frequencies. That's why the CWT spectral waveform-based inverted reservoir simulations were developed for this pilot phase. This initiative allows for assessing the potential of GS within the exploration zones. Therefore, this study achieves these implications by utilizing the zero-phase spectral waveform-based lateral temperature variability reservoir simulations (TRSM) and 90° phase reversal spectral waveform-based lateral water-saturation variability reservoir simulations (WRSM) to identify the favourable locations for GS within the NNE-Indus Onshore. The conventional 40-Hz spectral waveform couldn't identify the fault re-activated strata. This might not have impacted vertical migrations within HRZ due to tuning effects. TRSM at 250–300 °C seismic-based temperatures (STemp) have simulated 2172–2185 m/s velocity, 2.117–2.12 g/c.c density, and 18–19 m thickness of GS. This implicates the thermal expansion, development of a dense-fractures network, and permeable pockets within the HRZ of GS. TRSM at 100–150 °C STemp has also simulated 2240–2280 m/s velocity, 2.132–2.139 g/c.c density, and 12–13 m thickness of GS. This implicates the thermal breakthrough due to thermally cooled (contracted) reservoirs and poor fracture networks with impermeable pockets within GS. WRSM at 90–95 % seismic-based water-saturations (SWater) have simulated 2651–2678 m/s velocity, 2.231–2.235 g/c.c density, and 18–20 m thickness of GS. This implies that smooth fluids flow with the lowest salinity within the HRZ of GS. WRSM at 70–75 % SWater have simulated 2524–2562 m/s velocity, 2.218–2.21 g/c.c density, and 17–18 m thickness of GS. This implicates the poor and undulated fluids flow with increased salinity within HRZ of GS. However, the conjunction of TRSM and WRSM at 200–250 °C STemp and 80–85 % SWater has resolved a strong lateral high-amplitude anomaly between the 2210-2185 and 2627–2651 m/s simulated velocities, 2.12–2.129 and 2.215–2.231 g/c.c simulated densities, and 16–18:21–23m simulated thickness. Spectral waveform-based linear regression shows a strong R2 > 0.97 between STemp and SWater. This indicates the presence of pure stratigraphic-based HRZ resources of GS within the 650m offset distance from the parent well (Miano-08). Consequently, it commends the horizontal well-path trajectory for drilling the GS at 35° along meandering channelized sedimentary-fluxed GS at <1° inclined stratigraphic trap. Subsequently, these simulations develop a thermal-porosity high-temperature renewable GS proto-type. This prototype has the potential for converting steam to electricity. Hence, the GS proto-type has strong implications for a successful pilot phase installation of GS and starting the electricity production from huge and high-temperature steam reserves. Consequently, the presented workflow can serve as an analogue to extract the steam for cost-economic electricity production from global GS.