The Rock Well Technique utilizes well-established mining and drilling practices to tunnel beneath mature, depressurised, shallow oil reservoirs and drill a high number of closely-spaced up-ward sloping horizontal wells into the oil-bearing zone from a sequence of underground chambers (drill stations). The oil is extracted through gravity drainage, collected in underground facilities and pumped to the surface.

The construction of the tunnel and drill stations provides an underground platform from which to drill for oil. The proximity and location of the drill stations below the reservoir result in low per well drilling and completion costs compared with conventional drilling methods: distance to the reservoir is relatively short, drilling in non-reservoir rock is minimized, and no downhole equipment is required to produce the oil.

This allows for a high number of wells to be drilled into the oil-bearing zone. Compared to conventional drilling methods, the resulting well density produces extensive and efficient reservoir contact, which, combined with the constant effect of gravity drainage, produces high recovery factors relative to conventional primary, secondary and tertiary recovery techniques.

Please refer to Professor Michael Economides' report summarizing an investigation on gravity drainage conducted by petroleum engineers at Texas A&M University.

The company uses specific reservoir assessment criteria to identify oil fields that are optimal for the application of the Rock Well Technique. The target assets are typically large, mature, depressurised fields in advanced stages of decline, with quantifiable reserves of stranded oil. Consequently, as Rock Well operates in mature oil fields that are currently in operation or stripper production there is usually an extensive amount of current and historical data available on these target fields, such as production logs, core samples and reservoir information, which enables accurate reservoir mapping and provides strong evidence of the presence of oil. Similarly, there generally tends to be existing, easily accessible surface infrastructure, such as pipelines, roads, railroads and access to refineries, that enables an immediate route to market.

The nature and location of the target assets, combined with some of the key features of RWT, significantly mitigates many of the key risks associated with oil production and greatly reduces exploration costs.

In addition, RWT has a beneficial environmental impact on its target assets. The move to underground operations, typically with only one or two single surface access points , combined with consolidated production facilities , allows for minimal surface disturbance. The transition from conventional surface production to RWT development and production allows land previously disturbed by the latter to be reclaimed and returned to nominal natural condition.

Rock Well's approach to the environment.