Oilfield Glossary

BOE – Barrels of Oil Equivalent – is a method of equating the energy produced by a hydrocarbon gas to a standard oil measurement. one barrel of oil has about the same heat producing capacity as 6,000 ft3 of gas at standard conditions

BOPD – Barrels of oil produced per day.

Bonus – The amount of money paid to a mineral owner up front upon the signing of a lease. This is typically a one time payment for a lease agreement, however this lease component can be negotiable in value and in frequency of payment.

Blowout – an uncontrolled flow of gas, oil, or other well fluids into the atmosphere or into an underground formation. a blowout, or gusher, can occur when formation pressure exceeds the pressure applied to it by the column of drilling fluid. Blowouts are usually prevented with the use of a blowout preventer.

Chalk – a soft, white, powdery limestone consisting chiefly of fossil shells of foraminifers.

Commitment Letter – A letter from an oil or land company that typically offers a mineral owner a specified bonus amount, royalty rate percentage, and a lease term for their minerals. Signing this letter commits the mineral owner to signing a “Standard Lease” with the offering company. Typically the “Standard Lease” is signed without the benefit of negotiating the terms of the lease.

Hydralic Fracturing – An operation in which a specially blended liquid is pumped down a well and into a formation under pressure high enough to cause the formation to crack open, forming passages through which oil can flow into the wellbore. Sand grains, aluminum pellets, glass beads, or similar materials are carried in suspension into the fractures.

Lease Term – The term of the lease, usually in years. 5 year terms are industry standard, however these terms are negotiable.

Lineament – any long natural feature on the surface of the earth, such as a fault, esp as revealed by aerial photography.

Log – A systematic recording of data, such as a a driller’s log, mud log, electrical well log, or radioactivity log. many different logs are run in wells to obtain various characteristics of downhole formations.

Mineral Owner – A person(s) who own the subsurface minerals under a parcel of land. Minerals may be allocated by specific name such as “Coal Only”, Oil and Gas” or by strata as called out in a minerals lease agreement.

Negotiated Lease – A lease that has been negotiated with the leasing oil company by the mineral owner. Typically conducted with the assistance of an oil and gas attorney representing the interests of the mineral owner.

Play – the extent of an oil bearing formation, or the activities associated with petroleum development in an area

Proppant – A granular substance (sand grains, aluminum pellets, or other material) that is carried in suspension by the fracturing fluid and that serves to keep the cracks open when fracturing fluid is withdrawn after a fracture treatment.

Porosity – The percentage that the volume of the pore space bears to the total bulk volume. the pore space determines the amount of space available for storage of fluids.

Permeability – The ability of a rock to transmit fluid through the pore spaces. Porosity and Permeability are not directly related as a rock may possess high porosity but have low permeability.

Royalty – the percentage of the revenue of from hydrocarbons produced from a well paid to the mineral owner.

SPUD In – To begin drilling; to start the hole.

Standard Lease – A lease prepared by the oil company that is typically written to favor their interests over those of the mineral owner.

Section – a section is an area nominally one square mile, containing 640 acres

Surface Owner – A person(s) who own the surface rights to a property.

Surface Lease – A lease negotiated by an oil company with a surface owner for rights to access their subsurface minerals using the surface owners property.

Sonic log – A type of acoustic log that records the travel time of sounds through objects, cement, or formation rocks. often used to determine whether voids exist in the cement behind the casing in a wellbore

Tight formation – A petroleum- or water-bearing formation of relatively low porosity and permeability.

TD – Total Depth of a well. In horizontal wells this includes the total feet drilled, not necessarily the absolute depth of a well.

Township – A survey township is simply a geographic reference used to define property location for deeds and grants as surveyed and platted by the General Land Office (GLO). A survey township is nominally six miles (sections) square

Vitrinite reflectance (VF) – is used for determining the thermal maturity of the shale.  Vitrinite reflectance is sensitive to temperatures that correlate to hydrocarbon generation (60 to 120 degrees C).  Generally, onset of oil generation in an oil-prone shale is a VF of 0.6% and a VF of >1.35%, while the onset of generation in a gas-prone shale is a VF of 0.8% and a VF of >2%

Vitrinite – Vitrinite is one of the primary components of coals and most sedimentary kerogens. Vitrinite is a type of maceral, where “macerals” are organic components of coal analogous to the “minerals” of rocks. Vitrinite has a shiny appearance resembling glass (vitreous). It is derived from the cell-wall material or woody tissue of the plants from which coal was formed.

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