Glossary

Depleted Well
Unproductive well or one not permitting profitable development of petroleum.

Dry Gas
Natural gas taken from a well almost entirely lacking in liquid hydrocarbons; also designates a processed gas.

Field
Geographic zone composed of one or several deposits of hydrocarbons and sharing the same infrastructure or a common infrastructure.

Formation
Subterranean layer composed essentially of the same rock or rocks of the same type and thickness.

Fracturation
Operation consisting of pumping special fluids under pressure into the well in order to crack the producing layer and with the goal of facilitating the flow of fluids from the reservoir to the well.

Geophone
Sensor that detects sounds in the field of seismic surveys.

Geophysics
Science concerned with the physical features and phenomena of the Earth.

Hydrocarbons
A big family of organic compounds existing in liquid, solid or gaseous form and composed solely of carbon and hydrogen, the basis of all petroleum products.

Light Crude Petroleum
Petroleum of low density in the liquid state that flows easily at the ambient temperature.

P&A (plugged and abandoned)
Conversion of a drilled well to present no danger to the environment or to supply drinking water, while leaving it indefinitely without further attention.

Permeability
Property of a rock reservoir allowing fluids to pass through easily; predisposition of such a migration.

Porosity
Volume of space (pores) in the rock, likely to have absorbed petroleum and gas (as a sponge absorbs water); open or empty space in the rock.

Sandstone
Compact sedimentary rock composed mainly of quartz and feldspar. Common, it encloses accumulations of petroleum, natural gas or water.

Sedimentary Rock
Rock formed by the accumulation of sediments or organic materials and, consequently, likely to contain hydrocarbons.

Seismic Surveys
Method of gathering and recording shock waves emitted and reflected from subterranean rock layers with a view to creating detailed models.

Trap
Porous and permeable rock surmounted and delimited by impermeable, non-porous rock, hindering the migration of petroleum and gas that accumulate there.