cap rock


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Related to cap rock: reservoir rock, source rock

cap rock

[′kap ‚räk]
(geology)
An overlying, generally impervious layer or stratum of rock that overlies an oil- or gas-bearing rock.
Barren vein matter, or a pinch in a vein, supposed to overlie ore.
A hard layer of rock, usually sandstone, a short distance above a coal seam.
An impervious body of anhydrite and gypsum in a salt dome.
References in periodicals archive ?
The rare desert rains find their way through cracks in the cap rock and dissolve the salt to form small caves that flow down toward the Dead Sea.
In geological aspects, the tightness of the cap rock is the basis to ensure the security of oil storage.
Blunt, "Reactive transport modelling of geologic C[O.sub.2] sequestration in saline aquifers: The influence of pure C[O.sub.2] and of mixtures of C[O.sub.2] with C[H.sub.4] on the sealing capacity of cap rock at 37[degrees]C and 100bar," Chemical Geology, vol.
The transitional reservoir (trans-res) sandstones from the South Kandava onshore structure (located 0.2-0.3 m below the Lower Ordovician cap rock formation) are characterized by a higher carbonate cement content than the other studied pure reservoir sandstones.
There are countless, and even famous, examples of oil explorers and geologists finding all the right conditions for an oilfield only to discover, when the exploration well drill bit finally reaches the reservoir, that the oil was drained away due to a hole in the cap rock. The most dramatic case of this was "Mukluk," a very expensive well drilled by Sohio Petroleum (now BP) in 1981 in Harrison Bay off the Colville River delta of the North Slope.
The data collected by the project on the rock structures in which the C[O.sub.2] will be stored, the sealing cap rock and other features of the stores will be modelled and analysed to assess the stores' capability to securely contain C[O.sub.2].
Vari-Stem offers increased fragmentation, fracturing and cap rock breakage; and reductions in fly rock, air blast, stemming ejection, dust, noise and oversized rock.
It can also deform a bitumen formation so badly as to "reduce rock strength, induce new fractures or re-activate existing fractures posing contained risk of containment or breach of cap rock," say experts at the giant oil servicing company Schlumberger.
*Note: If a seismic amplitude anomaly caused by the interface of a cap rock and a reservoir rock is further supported by a so called AVO effect the chances for the presence of hydrocarbons in the reservoir rock is often greatly increased.
Third is a four-way tie between Tanqueray Malacca, Fords gin, Cap Rock Colorado Organic gin and Uncle Val's Botanical gin.
In order to achieve the highest detection performances, antennas should be placed away from the periphery of the dome (including its cap rock).
"The scale of the mine is such that many large, non-vegetated flat open areas containing removed and graded cap rock within the 1,550-acre site could potentially be used for utility -scale solar development," the report says.