geology Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...

, a petroleum play, or simply a play, is a group of

oil field A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence ...

s or prospects in the same region that are controlled by the same set of geological circumstances. The term is widely used in the realm of exploitation of hydrocarbon-based resources. The play cycle normally exhibits the following steps: # initial observations of a possible oil reserve # testing and adjustments to initial estimates of extraction # high success in locating and extracting oil from a reserve # lower success as the reserve is depleted # continued decrease in further exploration of the region A particular

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostra ...

structural A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such ...

geologic setting is also often known as a ''play.'' For example, in a relatively unexplored area (such as the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...

) one might speak of the "Paleozoic play" to refer to the potential oil reserves that might be found within

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

strata. In a well-explored basin such as the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

, explorers refer to the "Wilcox play" or the "Norphlet play" to collectively designate the production and possible production from those particular geological formations, of

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

and

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

age respectively.https://pubs.usgs.gov/of/2017/1111/ofr20171111.pdf A play may also be a broad category of possible reservoirs or rock types, as in the

turbidite A turbidite is the geologic deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing Turbidites wer ...

play of offshore

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

or the carbonate play in the East

Java Sea The Java Sea ( id, Laut Jawa, jv, Segara Jawa) is an extensive shallow sea on the Sunda Shelf, between the Indonesian islands of Borneo to the north, Java to the south, Sumatra to the west, and Sulawesi to the east. Karimata Strait to its nort ...

, or to the structural geology of the setting, as in the ''sub-upthrust play'' of

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

. Sometimes the word ''play'' is applied to a geographic area with hydrocarbon potential, as the South Texas play or the Niger Delta play, but usually "play" is used with the sense of restricting discussion to exploring a particular geologic setting. Thus one might have both the Wilcox play and the Norphlet play (among others) in partially overlapping areas of the coast of the Gulf of Mexico; the ''Gulf of Mexico deep-water play'' might or might not include elements or particular locations appropriate to either the Wilcox or the Norphlet, or both. The term is one of convenience for discussion, and may refer to geologic time intervals, rock types, structures, or some combination of them.

References

Further reading