This is a ‘go-to’ guide for decision makers and professional explorers – of the suitability and applicability of each technology in a variety of geological settings. The guide looks at specific hurdles for de-risking the subsurface, such as hard chalk at seabed, salt and basalt and indicates what the optimal technology combinations are best to overcome them. It also gives an indicative cost required for each technology broadly relative to that of a conventional seismic survey.

This book demonstrates that there are other approaches that when used alone, or in conjunction with seismic, can considerably reduce the uncertainty and risk of a given opportunity. Non-seismic technologies have a risk reduction role throughout the exploration value chain, from frontier basin entry exploration through to development and production and on into carbon capture and storage.

Integration is a theme running through our commentary alongside designing the survey with an understanding of the geological model you plan to validate. This is particularly the case with gravity/magnetics and Full Tensor Gradiometry (FTG) techniques for which there are non-unique outcomes for a given gravity response. Hence their best application is when using in combination with either refraction seismic or conventional reflection seismic.

As well as providing direct imaging in their own right, gravity and refraction seismic add significant value in helping to greatly improve the migration of seismic data. This is particularly the case when seismic data quality is compromised due to the presence of difficult lithologies in the overburden (e.g. salt, basalt and chalk) or to increase the resolution at depth. We review of marine electromagnetic methods, in which we explain that if correctly applied, in the right geological conditions, marine electromagnetic has an important role to plan in prospect de-risking and reservoir management.

The chapter describes the exploration process which is focussed on building a geological model of the subsurface which predicts the presence of hydrocarbons, and through a process of investment, reduces the uncertainty of the model so the risk of project failure is acceptable.

A staged approach for exploring for, and producing, oil and gas is described. First, explorers screen basins and find potentially prospective hydrocarbon provinces. Following this regional screening, they identify specific plays that may contain the elements for a working petroleum system (reservoir, source rocks and seal). Then, following a successful exploration programme that identified hydrocarbons, the next stage appraises the scale and productive characteristics of the discovery in order to design an effective, economic development. The traditional final stage is the production of the discovered hydrocarbons, where this is commercially attractive. In many basins the economic life of a reservoir is being extended to allow for the sequestration of carbon dioxide as a vital element in our ability to reduce carbon emissions.

The application of geophysical technologies to each stage of the exploration and production process is described through an articulation of the key problem that needs to be solved. The choice of which technology to use is determined by the geophysical property change and its scale.