Exploration

INTRODUCTION

Dewhurst Group (DG) is an American geoscientific and engineering company providing specific services for global geothermal exploration, development, and financing. Our recognized geologists, geophysicists, and engineers have many years of experience in geothermal-energy generation. The goal of our service is to reduce project-development risk in a pragmatic, iterative, and cost-effective manner. Final service products include, but are not limited to: conceptual geological and reservoir models, reservoir analyses, drilling engineering, project management, civil and infrastructure management, productivity simulations, and bankable technical-feasibility studies.

EXPLORATION

Exploration is the first step in developing a potential resource. DG provides pragmatic, cost-effective solutions for both surface and subsurface operations. Our exploration services range from early desktop studies and remote-sensing applications, to geoscientific field studies including geology, geophysics, and geochemistry. In order to maximize the value of past efforts, we provide legacy-data review and data-gap analyses, so that previous operations may be integrated into customized solutions for our clients. DG understands the importance of risk mitigation in the exploratory phase of geothermal development. Risk mitigation is central to our philosophy, which strives for high-value exploratory investment and low-risk solutions.

Geology

Geological studies are critical to the success of a geothermal project and provide preliminary data on resource characteristics such as reservoir type, scope, working fluid, capacity, accessibility, and potential risk-mitigated target areas. DG’s geologists can provide the following services, as well as customized solutions:

• Geologic mapping
• Identification of geothermal mineralization
• Structural and stratigraphic maps and interpretations
• Detailed fault and fracture characterization and analyses
• Network integration and analysis of discrete fracture reservoirs
• Spatial Spectral Analysis (SPAN)
• Terrestrial and airborne LiDAR project management

Geophysics

Geophysics is the primary industry-standard science for defining the dimensions and structure of a geothermal field, both on the surface and at depths where the reservoir and main structures related to permeability are found. Our geoscientific team has expertise in related fields that allow us to perform field campaigns and appropriate interpretation and analysis. DG’s team is well versed in the methods of volcanology, geophysics, inversion theory, and data interpretation, all of which are key to project success. Our portfolio of geophysical services includes:

• Resistivity and magnetotelluric surveys:
‐ Broadband Magnetotellurics (BMT)
‐ Low-frequency Magnetotellurics (LMT)
• Electromagnetics (EMT)
• Shallow Temperature Probe (STP) observations
• Gravimetric and magnetic surveys and analyses

Geochemistry

Geochemical techniques are useful for monitoring, sampling, and analyzing fluids (both liquids and vapors) from hot springs, fumarole emissions, gases, surface water, and precipitation, in order to identify regions of potential upflow, outflow, and recharge. Geochemistry can also be used to determine the fluid-mineral equilibration temperatures of a geothermal system. Fluid characterization is crucial to initiate development procedures such as well design, well siting, power plant design, and even reservoir engineering. Our team of field geochemists is experienced in geothermal studies and has worked on projects that have successfully transitioned from exploration to development.

Conceptual and Reservoir Modeling

DG integrates diverse exploratory data (acquired through field campaigns in geology, geophysics, geochemistry, hydrogeology, and temperature measurements) to model a potential geothermal reservoir. Such an integrated model is highly dependent on the quality and quantity of data collected by field operations in the exploration phase. In the modeling phase, DG determines appropriate strategies to conclude exploratory procedures and initiate development. Modeling can lead to the advancement of well planning, drill-site selection, future simulations, reservoir capacity estimation, and power plant design. Our modeling services include:

• Conceptual integration and interpolation of data
• Reservoir geometry and geodynamics
• Reservoir monitoring
• Numerical reservoir modeling
• Conceptual reservoir modeling
• Spatial interpolation
• Determination of drilling targets
• Reservoir development concepts
• 3D conceptual model development
• Reservoir capacity modeling
• Make-up well targeting and planning
• Production and injection operations
• Well maintenance
• Resource optimization and expansion