Choosing a location for oil drilling is by no means a straightforward process. It involves extensive planning, the collaboration of various scientific parties and a great deal of patience. With factors ranging from geology to costings, from the presence of infrastructure to the proof of prior development, choosing a new oil field is a multi-layered and complex process. The team here at TriStone Holdings Ltd, who themselves plan on developing a new prospect in the US, wanted to look at the key variables informing the process behind choosing an oil field.
The Prospect Profile
First and foremost, you obviously have to determine and pick somewhere that will yield good levels of oil. There’s no point setting up an oil field where there is none! With that in mind, the most important stage in choosing a location for a new oil field is the geological profile conducted by a petroleum geologist. Oil is typically located within sedimentary rock basins and once a potential area has been located, the geologist must carry out a geophysical survey in order to look at the following aspects:
- Source. The source rock is that which generates the hydrocarbons (the oil) deep underground.
- Reservoir. The reservoir rock is where the hydrocarbons from the source rock seep into, and are subsequently held in a trap.
- Seal. The seal prevents the hydrocarbons escaping the reservoir rock.
- Trap. This is where the hydrocarbons are held in a quantity where it becomes profitable for a drilling company to drill into and extract. It comes in the form of a stratigraphic trap in the case of sandstones and structural traps in carbonate rocks.
- Timing. The formation must indicate a specific sequence of events, geologically speaking.
- Maturation. The source rock must undergo immense heat and pressure to lead to the production of the resulting oil.
- Migration. The process whereby oil moves from its initial source rock into the reservoir rock.
These factors help the geologist build up a profile determining the viability of the land in question as a potential oil field. Should they offer a positive picture – as may be provided by processes such as seismic reflection and mud-logging – then, and only then, can oil companies look towards the next selection criteria.
Having ascertained that a prospect is indeed viable from a drilling perspective, the next step is to assess its feasibility, economically speaking. Drilling operations, even when run optimally and with today’s help from automation and AI, are not cheap affairs. It’s tricky, however, to put an exact costing on what oil yield is needed for the venture to be profitable, especially when there’s such variability in the oil market, even day to day.
When you then factor in the global trends towards more sustainable energy sources and increasingly scrupulous legislation and government pressure, you have to be sure that an oil well will make its money back, and then some. The economic modelling for TriStone Holdings’ own prospect: The Viola Prospect, for example, has confirmed excellent potential for the commercial production of oil; when choosing a new oil field, given that there’s so little room for error, you have to have this degree of surety.
Something which greatly affects the economics of a drilling project is the infrastructure surrounding an oil prospect. Considerations must be borne in mind with regards to transporting not only the fuel itself through tankers and pipelines, but the site’s operations as well.
Do you choose a well with lower yield but better, existing infrastructural frameworks? Or do you look to investigate a high-production prospect, but one which will require an entire infrastructure, including roads and pipelines, to be set up from scratch? This is a difficult enough question, in itself, but it isn’t even as cut-and-dry as that. This is because you need to factor in other considerations like environmental concerns.
Creating new roads, for example, can have substantial ramifications on the immediate area, with regards to CO2 emissions and the distribution of nutrients within local ecosystems. Oil companies must consider these infrastructural implications almost as carefully as they do the site and its geology itself.
It’s all very well finding a potentially successful development, but what about once that well has run dry? Most oil companies now are looking for extensive prospects that provide upside potential for future commercial oil projects beyond the initial drilling project. The Viola Prospect, for example, has a large 480-acre lease block with which to work in the future.
Another consideration relates to using oil fields when there’s no oil left. It concerns how oil fields can be used once all their recoverable oil has been welled. Whereas previously, companies may simply have abandoned these fields, nowadays the depleted oil fields are being used for the storage of gases like carbon dioxide. They make ideal candidates for this given their impervious physical characteristics.
As you may can see, then, drilling isn’t solely about the presence of the black stuff underground. The choice of an oil field has to factor in a whole raft of considerations. Considerations beyond the initial ‘presence of oil?’ question. If finding an oil field that met all the above criteria was easy, then everybody would do it! The complexity of discovering such prospects takes time and serious expertise.
If you’d like to find out more about our new oil field, then get in touch! Contact TriStone Holdings today on 0800 055 7079. Over the past few months, we’ve featured in several industry publications, click here to find out more!