Oil & Gas Terms in Category E

Elevator links

Cylindrical bars that support the elevators and attach them to the hook.

Also called elevator bails.

Elevator bails

See elevator links

Expansion joint

A device used to connect long lines of pipe to allow the pipe joints to expand or contract as the temperature rises or falls.

Expendable plug

A temporary plug set of a psa, landed in a production packer to convert it to a bridge plug.


An elastic material made of synthetic rubber or plastic; often the main component of the packing material in blowout preventers and downhole packers.


The decomposition of a chemical compound brought about by the passage of an electrical current through the compound or through the solution containing the compound.

Corroding action of stray current is caused by electrolysis

Effective porosity

The percentage of the bulk volume of a rock sample that is composed of interconnected pore spaces that allow the passage of fluids through the sample.

See porosity.

Electric line

See electric well log


Abbr: equivalent circulating density.

Effective permeability

A measure of the ability of a single fluid to flow through a rock when another fluid is also present in the pore spaces.

Compare absolute permeability, relative permeability.