Compaction and cementation of sediments to the degree that they become coherent, relatively solid rock

(a)  

Containing chert, a sedimentary rock and a variety of quartz made of extremely fine-grained, or cryptocrystalline, silica, also called chalcedony

(a)  

Containing shale, a fine-grained, fissile, detrital sedimentary rock formed by consolidation of clay- and silt-sized particles into thin, relatively impermeable layers.

(a)  

Containing tuff, which is lithified volcanic ash

(a)  

Containing vugs, which are cavities, voids or large pores in a rock that are commonly lined with mineral precipitates

(a)  

Contaminated with sulfur or sulfur compounds, especially hydrogen sulfide

(a)  

Continental shelf, or the area at the edges of a continent from the shoreline to a depth of 200 m [660 ft], where the continental slope begins

(a)  

Dense, fine-grained carbonate mud or rocks composed of mud that forms by erosion of larger carbonate grains, organic precipitation (such as from algae), or inorganic precipitation

(a)  

Describing a relatively impermeable reservoir rock from which hydrocarbon production is difficult

(a)  

Describing material deposited in or growing in a marsh

(a)  

Describing parallel or subparallel, closely-spaced, overlapping or step-like minor structural features in rock, such as faults and tension fractures, that are oblique to the overall structural trend

(a)  

Describing rocks or sediments containing particles that are silt- or clay-sized, less than 0.625 mm in size

(a)  

Describing sandy-textured rock or sediment

(a)  

Describing sedimentary rock that contains clay minerals

(a)  

Describing the environment and conditions of the marine zone between low tide and the edge of the continental shelf, a depth of roughly 200 m [656 ft]

(a)  

Different from what is typical or expected, or different from what is predicted by a theoretical model

(a)  

Directionally uniform, such that the physical properties of the material do not vary in different directions

(a)  

Exploration activity located in offshore areas where water depths exceed approximately 600 feet [200 m], the approximate water depth at the edge of the continental shelf

(a)  

Fine-grained sediments less than 0.0039 mm in size

(a)  

Folded structures associated with strike-slip faults

(a)  

For hydrocarbons to move from their source into reservoir rocks

(a)  

Formation water with low salinity

(a)  

Gas produced from a relatively impermeable reservoir rock. Hydrocarbon production from tight reservoirs can be difficult without stimulation operations

(a)  

Gas that is dissolved in a liquid, such as water or oil

(a)  

Generally, the study of how matter deforms and flows, including its elasticity, plasticity and viscosity

(a)  

Geologic components and processes necessary to generate and store hydrocarbons, including a mature source rock, migration pathway, reservoir rock, trap and seal.

(a)  

Global sea level variations. Changes in sea level can result from movement of tectonic plates altering the volume of ocean basins, or when changes in climate affect the volume of water stored in glaciers and in polar icecaps

(a)  

Having directionally dependent properties

(a)  

In folded rocks, the imaginary surface bisecting the limbs of the fold

(a)  

In plate tectonics, a failed rift arm

(a)  

In sequence stratigraphy, a section of fine-grained sedimentary rocks that accumulated slowly, thereby representing a considerable span of time by only a thin layer

(a)  

In the case of a body of rock, to be exposed at the surface of the Earth

(a)  

In the original location or position, such as a large outcrop that has not been disturbed by faults or landslides

(a)  

Incorporation of water into the atomic structure of a mineral, i.e., the chemical combination of water and another substance

(a)  

Innermost layer of the Earth.

(a)  

Layers of sedimentary rock.

(a)  

Lithified volcanic ash

(a)  

Located down the slope of a dipping plane or surface

(a)  

Located up the slope of a dipping plane or surface. In a dipping (not flat-lying) hydrocarbon reservoir that contains gas, oil and water, the gas is updip, the gas-oil contact is downdip from the gas, and the oil-water contact is still farther downdip

(a)  

Location relative to the boundary of a tectonic plate, particularly a boundary along which plate tectonic activity is occurring or has occurred.

(a)  

Mass per unit of volume.

(a)  

Material deposited in an alluvial environment, typically detrital sediments that are poorly sorted

(a)  

Materials, especially rock masses, that formed in their present location and have not been transported

(a)  

Materials, especially rock masses, that formed in their present location and have not been transported

(a)  

Minute organisms that float or drift passively near the surface of oceans and seas

(a)  

Natural gas that contains less methane (typically less than 85% methane) and more ethane and other more complex hydrocarbons.

(a)  

Natural gas that occurs in the absence of condensate or liquid hydrocarbons, or gas that has had condensable hydrocarbons removed

(a)  

Natural gas, predominantly methane [CH4], generated during coal formation and adsorbed in coal

(a)  

Naturally-occurring, inflammable organic matter formed from kerogen in the process of petroleum generation that is soluble in carbon bisulfide.

(a)